A total of 28 accessions of rice (Oryza sativa L.) germplasms were collected from International Rice Research Institute (IRRI), Philippine and Gene Pool of China National Rice Research Institute (CNRRI). These germpla...A total of 28 accessions of rice (Oryza sativa L.) germplasms were collected from International Rice Research Institute (IRRI), Philippine and Gene Pool of China National Rice Research Institute (CNRRI). These germplasms were attributed as a Donor Gene Pool, consisting of 27 diverse morphological marker lines with each having a unique valuable trait (gene), and the recurrent parent-Zhefu 802, an early-season indica cultivar in south of China in the 1980s and 1990s. A set of 27 isogenic lines with 2-3 markers on every chromosome were obtained after more than 10 successive backcrosses. Moreover, 15 accessions of double-marker isogenic lines were developed by further pyramiding markers on the same chromosome. Key agronomic traits such as heading date, plant height, tillering number and panicle length in this set of lines were similar to that of Zhefu 802 except the marker traits.展开更多
[Objective] The study aimed to provide theoretical basis for development and application of molecular marker breeding technique to obtain Bombyx mori near-isogenic lines （NILs）. [Method] Thermotolerance gene was int...[Objective] The study aimed to provide theoretical basis for development and application of molecular marker breeding technique to obtain Bombyx mori near-isogenic lines （NILs）. [Method] Thermotolerance gene was introduced into sensitive variety Ou17 by developing NILs and recurrent backcross,then through six generations of backcross,thermotolerance-assisted selection,and two generations of self-cross. [Result] Bombyx mori NILs carrying thermotolerance gene （new germplasm） were produced. Meanwhile,thermotolerance level of progenies of each backcross and molecular markers of NILs were determined,and then attempts were made to produce practical thermotolerance hybrids by using thermotolerance varieties whose thermotolerance gene is linked to SSR markers. [Conclusion] The study successfully construct thermotolerance NILs,monitor thermotolerance level and breeding results of progenies of each backcross,and determine molecular marker of NILs.展开更多
Based on both cDNA sequence of barley powdery mildew resistance control element Mlo and DNA sequence of the known putative disease resistance gene from Triticum monococcum L., we designed some primers to amplify resis...Based on both cDNA sequence of barley powdery mildew resistance control element Mlo and DNA sequence of the known putative disease resistance gene from Triticum monococcum L., we designed some primers to amplify resistant homologous sequences in the near isogenic lines (NILs) of powdery mildew resistance using RT-PCR method. Two expressed cDNA fragments were isolated from wheat genome. One showed 83% homology to the Mlo gene of barley. The other contained two possible open reading frames (ORFs). NBS conservative domains 2, 3 of disease resistance gene and 13 LRR structures similar to rice Pib protein terminal were found respectively in the two ORFs. It indicated that the latter fragment belongs to NBS-LRR-like genes. The obvious difference of RT-PCR products was observed between the before challenged and the challenged for 72 h by Blumeria graminis f. sp. tritici, which, implied that this sequence could be associated with disease resistance of wheat. Using nulli-tetrasomic lines of 'Chinese Spring', the NBS-LRR-like gene had been located on chromosome 1D.展开更多
In this study,silkworm strain T6,tolerant to fluoride,and silkworm strain 733xin,highly sensitive to fluoride,were used to construct the near-isogenic lines.300 random primers were used in RAPD amplification to DNAs o...In this study,silkworm strain T6,tolerant to fluoride,and silkworm strain 733xin,highly sensitive to fluoride,were used to construct the near-isogenic lines.300 random primers were used in RAPD amplification to DNAs of these lines.A molecular marker named S207 was found linked to the fluoride tolerance gene.Examination to F 2 segregated individuals of the above lines verified that this molecular marker was reliable.Subsequently,the molecular marker was cloned into a T vector (pUCm-T) for sequencing.Comparing with sequences available in the GenBank showed that this molecular marker was novel.We plan to convert it into a SCAR marker to facilitate establishment of a molecular marker assisted breeding system.展开更多
USSR5, a japonica rice variety from the former Soviet Union, is an extremely early maturing rice variety. To elucidate the genetic basis for its early heading, genetic analysis was carried out by crossing it with a se...USSR5, a japonica rice variety from the former Soviet Union, is an extremely early maturing rice variety. To elucidate the genetic basis for its early heading, genetic analysis was carried out by crossing it with a set of major gene nearly isogenic lines （NIL） and QTL-isogenic lines. The early heading of USSR5 was attributed to the presence of photoperiod-insensitive alleles at E1 and Se-1 gene, the photoperiod-sensitive inhibitor gene i-Se-1, and the dominant earliness gene Ef-1. Analysis of a backcrossed population （BCIF1） derived from the cross USSR5 x N22 indicated that two quantitative trait loci （QTL） for early heading were located on chromosomes 7 and 8, accounting for 27.4% and 11.2% of the phenotypic variance, respectively, with both early alleles originating from USSRS. From an F2 population of the same cross, early heading QTLs were detected on chromosomes 1, 2, 7, 9, and 10, with individual QTL accounting for between 4.1% and 15.4% of the phenotypic variance. Early heading alleles at four of these five QTLs originated from USSRS. A comparison of chromosomal locations suggests that one of these QTLs may be identical with the known gene Hd4 （E1）. The relationship between the other QTLs and known genes for heading date are not clear. USSR5 is a promising source for propagating earliness for the development of improved early heading rice varieties.展开更多
Genetic polymorphism of the major histocompatibility complex （MHC） B-LBⅡ gene was studied by amplification of exon 2 using PCR, followed by cloning and DNA sequencing in eight indigenous Chinese chicken populations...Genetic polymorphism of the major histocompatibility complex （MHC） B-LBⅡ gene was studied by amplification of exon 2 using PCR, followed by cloning and DNA sequencing in eight indigenous Chinese chicken populations. To reveal the genetic variation of the B-LB Ⅱ gene, 37 types of patterns detected by PCR-SSCP were investigated first, which would be used to screen novel B-LB Ⅱsequences within the breeds. The types of PCR-SSCP patterns and final sequencing allowed for the identification of 31 novel MHC B-LBⅡ alleles from 30 unrelated individuals of Chinese chickens that were sampled. These are the first designators for the alleles of chicken MHC B-LBⅡ gene based on the rule of assignment for novel mammalian alleles. Sequence alignment of the 31 B-LB Ⅱ alleles revealed a total of 68 variable sites in the fragment of exon 2, of which 51 parsimony informative and 17 singleton variable sites were observed. Among the polymorphic sites, the nucleotide substitutions in the first and second positions of the codons accounted for 36.76% and 35.29%, respectively. The sequence similarities between the alleles were estimated to be 90.6%-99.5%. The relative frequencies of synonymous and nonsynonymous nucleotide substitutions within the region were 2.92%±0.94% and 14.64%±2.67%, respectively. These results indicated that the genetic variation within exon 2 appeared to have largely arisen by gene recombination and balancing selection. Alignment of the deduced amino acid sequences of the β1 domain coded by exon 2 revealed 6 synonymous mutations and 27 nonsynonymous substitutions at the 33 disparate sites. In particular, the nonsynonymous substitutions at the putative peptide-binding sites are considered to be associated with immunological specificity of MHC B-LB Ⅱ molecule in Chinese native chickens. These results can provide a molecular biological basis for the study of disease resistance in chicken breeding.展开更多
This paper studies the offspring＇s genotype frequency of the selfing population on multiple alleles with limited loci.A recursive algorithm is given for it.It is discovered that the genotype frequency of homozygous g...This paper studies the offspring＇s genotype frequency of the selfing population on multiple alleles with limited loci.A recursive algorithm is given for it.It is discovered that the genotype frequency of homozygous gene of limited loci increases by generations.Relative increment reduces by generations and the genotype frequency tends to a definite value finally.The genotype frequency of limited loci with hybrid gene tends to 0 finally.But it is possibility that the genotype frequency increases in previous generations then reduces later.It is found that the number of the hybrid gene are more,the speeds tending to 0 are quicker.展开更多
[Objective] The study aimed to explore the method for directional breeding of a male-sterile line in oval-ecotype Chinese cabbage. [Method] Based on ＂Multiple Allele Hypothesis of Genic Male Sterile Chinese Cabbage＂...[Objective] The study aimed to explore the method for directional breeding of a male-sterile line in oval-ecotype Chinese cabbage. [Method] Based on ＂Multiple Allele Hypothesis of Genic Male Sterile Chinese Cabbage＂, an inbred line ＇06048＇ of oval ecotype was used as the receptor, and male fertile plant of ＇AB12＇ was used as the donor line. Crossing, backcross, selfing, testcross and sibling were ap- plied to transfer the multiple alleles under the directional genetic model. [Result] Segregation ratio of every generation was consistent with theoretical value. A new male sterile line with 100% male sterility and ＇06048＇ horticultural traits was ob- tained successfully, which accomplished the transfer of male sterile multiple allele and horticultural characters of receptor line at the same time. [Conclusion] The re- search verifies that the model of directional transfer is feasible, provides a theoreti- cal basis for the directional transfer of Chinese cabbage with other horticultural traits whose genotype is msms. The model can also be applied to other Brassica crops, to generate genetic male sterile lines with specific botanical traits and high-quality economic traits.展开更多
[ Objective] This study was to breed rice cultivars with multi-resistance to Orseolia oryzae （Wood-Mason）. [ Method] The Guangxi local cultivar GX-M001 （Jiangchao） with high resistance to Orseolia oryzae （Wood-Ma...[ Objective] This study was to breed rice cultivars with multi-resistance to Orseolia oryzae （Wood-Mason）. [ Method] The Guangxi local cultivar GX-M001 （Jiangchao） with high resistance to Orseolia oryzae （Wood-Mason） was used to hybrid with the known resistance cultivars ＂Kangwenqingzhan＂ （harboring GM5 gene）, OB677（ harboring GM3 gene） from Sri Lanka, HT1350 and high yield end quality cultivar ＂ Guiruanzhan＂. [ Result] Through pyramiding the multi-resistant genes via routine hybridization, the general resistances of the hybrids were remarkably enhanced. The grades of resistance were also improved, many of the combinations were endowed with a resistance at immune level （grade 0） ; and interestingly, the respective hybridization of GX-M001 （high resistance） with OB677（ medium resistance） and HT1350（suscepti- ble） also generate two lines at immune level, which is probably the effects of additive effects of genes.[ Conclusion] By routine hybridization, multiple genes were successfully pyramided, thus generating novel rice lines with multiple resistances. For the rice breeding scientists at the grass-roots level, the resistance-resistance pyramiding is an effective approach to breed high resistance cultivars.展开更多
Inflammation has been shown to play an important role in the progression of Alzheimer＇s disease （AD）. Recent epidemical study indicates that the incidence of AD in some populations is substantially influenced by th...Inflammation has been shown to play an important role in the progression of Alzheimer＇s disease （AD）. Recent epidemical study indicates that the incidence of AD in some populations is substantially influenced by the gene polymorphisms of the inflammation mediators. Meanwhile, an ensured risk factor, the ApoE ε4 allele is also reported to directly promote inflammation. Accordingly, it appears that an individual genetic background has partly determined his predisposition for AD by the extent of the inflammation response to the chronic stimulus by β-amyloid peptide （Aβ） deposits and other antigen stressor in the elderly. Hence we present a hypothesis that the inflammation genotypes may contribute to AD susceptibility. This may provide a new orientation both for future identification of individuals at risk and for personalized medication.展开更多
Objective: To study the features of microsatellite alterations on chromosome 8 and their asso- ciation with clinicopathological characteristics of hepatocellular carcinoma (HCC). Methods: Ten highly- ...Objective: To study the features of microsatellite alterations on chromosome 8 and their asso- ciation with clinicopathological characteristics of hepatocellular carcinoma (HCC). Methods: Ten highly- polymorphic microsatellite markers on chromosome 8 were selected to be detected for loss of heterozygosity (LOH), microsatellite instability (MSI) and allelic imbalance (AI) in 56 HCC using MegaBACE 500 auto- matic DNA analysis system. Results: LOH was found in 37 of 56 HCC (66.1%) on at least 1 locus, and the top three loci were D8S261(53.5%), D8S1721(52.5%) and D8S1771(52.5%). LOH frequency on D8S277 was signi?cantly higher in cases positive for serum HBsAg than in those negative for HBsAg (P <0.01). Similarly, LOH on D8S261, D8S298 and D8S1733 occurred more frequently in patients with negative HB- sAg than those with positive HBsAg (P <0.01). LOH on D8S298 and D8S1771 was more frequent in those tumors larger than 3 cm in size (P <0.05 or P <0.01). LOH frequencies of D8S1721 were signi?cantly higher in the patients with absent or not intact tumor capsule than in those with intact tumor capsule (P <0.05). LOH on D8S298 and D8S1771 was more frequently detected in tumors with intrahepatic metastasis than in those without intrahepatic metastasis (P <0.01). MSI was found in 12.5% (7/56) cases, and AI was found in 19.6% (11/56), no correlation was found between MSI and AI and clinicopathological character- istics of HCC. Conclusion: Frequent microsatellite alterations on chromosome 8 existed in HCC. LOH, which represents tumor suppressor gene pathway, plays a more important role in hepatocarcinogenesis; MSI representing mismatch repair gene pathway ranks next. LOH at a particula locus is associated with the clinicopathological parameters of human HCC.展开更多
The study aims at exploring the possibility of using the recovery ability af- ter drought stress-rewatering at vegetative growth stage as the evaluating index in water use efficiency （WUE） of winter wheat varieties....The study aims at exploring the possibility of using the recovery ability af- ter drought stress-rewatering at vegetative growth stage as the evaluating index in water use efficiency （WUE） of winter wheat varieties. ＇Jing 411 ＇, ＇Jinmai 47＇ and their 34 near isogenic lines （NILs） were used as test materials. Semi-automatic rainproof shelter and the percolating pools were used for simulating drought treat- ment. After suffering severe drought stress, winter wheat crops were rewatered at early jointing stage. The biomass accumulation after rewatering was determined as recovery ability index. In the meanwhile, plant height in the end of vegetative growth stage was measured, and WUE of varieties/lines was also determined. Thereafter, the differences in recovery ability, plant height and the population WUE, together with the correlation between recovery ability and population WUE were analyzed, respectively. The results showed that there were significant differences in recovery ability among some varieties/lines. The recovery ability was affected by both geno- type and environment, and the interaction existed in these two factors. Significant differences existed in plant height and population WUE among the 34 NILs along with their parents. There was a significantly positive correlation between recovery ability and plant height of varieties/lines. Recovery ability and plant height were very significantly and positively correlated with population yield WUE respectively. The re- sults indicated that recovery ability after drought stress-rewatering could be used as an evaluating index of population WUE under drought condition.展开更多
Vertical polyamide gel electrophoresis was used to investigate isozyme polymorphisms among different isolates （including wild and cultivated） of Porphyra katadai, Porphyra oligospermatangia, Porphyra yezoensis, Porp...Vertical polyamide gel electrophoresis was used to investigate isozyme polymorphisms among different isolates （including wild and cultivated） of Porphyra katadai, Porphyra oligospermatangia, Porphyra yezoensis, Porphyra haitanensis, and a hybridize species （Porphyra yezoensis x Porphyra haitanensis） sampled from China. Whereafter, the analyses of probable minimum loci numbers, observed alleles sum, genetic diversity, and unweighted pair-group arithmetic average （UPGMA） cluster were carded out. After initial activity and resolution testing of bands of 23 enzymes, 6 of them （MDH, ME, LDH, GDH, IDH and G-6-PDH） were proved to be appropriate for analysis of the full sample set. The probable minimum numbers of loci and alleles analyses showed that the five species of Porphyra had an extraordinary consistent result in ME loci and alleles. However, P. katadai and P. oligospermatangia differed from other three species of Porphyra in LDH and GDH loci and alleles. P. katadai was independent in the analyses of MDH and P. oligosperTnatangia and P. haitanensis differed from other three species in IDH analyses. Moreover, P. yezoensis and P. haitanensis were apart from other three species in G-6-PDH analysis. Taking one with another, P. katadai was relatively separated in the probable minimum numbers of loci and alleles analyses. The results indicated that the genetic variation among the five Porphyra species was limited with a genetic identity of 0.7550. The hybridize species （P. yezoensis x P. haitanensis） seemed to be high homologue with P. oligospermatangia, unexpectedly got relatively lower average genetic identities with both P. yezoensis and P. haitanensis. The 4 strains of P. yezoensis were relatively divergent with an average genetic identity of 0.7428, and P. katadai presented the most differentiated, compared with other species, which consistented with the result summarized in the probable minimum numbers of loci and alleles analyses.展开更多
Although a growing number of both sequence-based and microsatellite nuclear loci have been used to infer genetic structures, their relative efficiencies remain poorly understood. In our study, we used the Green-backed...Although a growing number of both sequence-based and microsatellite nuclear loci have been used to infer genetic structures, their relative efficiencies remain poorly understood. In our study, we used the Green-backed Tit (Parus monticolus) to explore the resolving ability of these two types of markers. The south-western and central mitochondrial DNA (mtDNA) phylogroups were divergent to some extent in sequence-based nuclear data, while mixed together in microsatellites data. The F ST values among clades were about four times lower in microsatellite loci than those in sequence-based nuclear loci. We are of the opinion that size homoplasy may have contributed to the inability of microsatellites to uncover differentiation. Our results suggest that sequence-based nuclear loci outperformed microsatellite loci in detecting population structures, especially those focused on populations with large effective population sizes. There was no significant correlation between F ST values and allelic size variability, which suggested that the efficiency of microsatellite loci in detecting genetic structure may be independent of their polymorphism. F ST is better than R ST in detecting intraspecific divergence due to the high variance of R ST . In agreement with sequence-based nuclear loci, microsatellite loci did resolve the genetic distinctness of the Taiwan Residents phylogroup. The genetic differentiation between the Taiwan Residents and continental clades may involve allopatric divergence without gene flow.展开更多
A SIT-BJT model is proposed for static induction thyristors （SITh） operation in the blocking state. On the basis of the physical mechanism, this model is presented analytically in terms of governing equations that l...A SIT-BJT model is proposed for static induction thyristors （SITh） operation in the blocking state. On the basis of the physical mechanism, this model is presented analytically in terms of governing equations that link the electrical parameters to the structural parameters. The model is verified by numerical simulation and theoretical analysis. Based on the model, the variations of the electrical parameters such as the potential barrier, the anode junction voltage drop, and the current amplification factor are studied and discussed.展开更多
AIM： To identify the variants in U rase 1 （UGT1A1） gene in Gilbert＇s syndrome （GS） and to estimate the association between homozygosity for TA insertion and GS in India, as well as the frequency of TA insertion ...AIM： To identify the variants in U rase 1 （UGT1A1） gene in Gilbert＇s syndrome （GS） and to estimate the association between homozygosity for TA insertion and GS in India, as well as the frequency of TA insertion and its impact among normal controls in India. METHODS： Ninety-five GS cases and 95 normal controls were selected. Liver function and other tests were done. The promoter and all 5 exons of UGT1A1 gene were resequenced. Functional assessment of a novel trinucleotide insertion was done by in silico analysis and by estimating UGT1A1 promoter activity carried out by ludferase reporter assay of appropriate constructs in Hep G2 cell line. RESULTS： Among the GS patients, 80% were homozygous for the TA insertion, which was several-fold higher than reports from other ethnic groups. The mean UCB level was elevated among individuals with only one copy of this insertion, which was not significantly different from those with two copies. Many new DNA variants in UGT1A1 gene were discovered, including a trinucleotide （CAT） insertion in the promoter found in a subset （10%） of GS patients, but not among normal controls. In-silico analysis showed marked changes in the DNA-folding of the promoter and functional analysis showed a 20-fold reduction in transcription efficiency of UGT1A1 gene resulting from this insertion, thereby significantly elevating the UCB level. CONCLUSION： The genetic epidemiology of GS is variable across ethnic interactions among UGT1A1 groups and the epistatic promoter variants modulate bilirubin glucuronidation.展开更多
To lay background for studying rejection mechanisms in xenotransplantation and developing the strategies for intervention, class I genes of swine leukocyte antigens (SLA) of three Chinese pig strains Bm, Gz and Yn wer...To lay background for studying rejection mechanisms in xenotransplantation and developing the strategies for intervention, class I genes of swine leukocyte antigens (SLA) of three Chinese pig strains Bm, Gz and Yn were cloned and sequenced. The cDNA of the class I loci P1 and P14 were amplified by RT-PCR and subjected to insert into sequencing vectors. All six allelic sequences we examined, each two for one Chinese strain, are not identical to those reported, which allows these novel sequences receiving their accession numbers AY102467- AY102472 from GenBank. This study further reveals that the homologies of MHC class I genes in their primary structures and the deduced amino acids between Chinese pigs (SLA) and human (HLA-A*0201) are better than those between pigs and mice (H-2Db/H-2Kb). The comparison also indicates that the amino acid residues critical for recognition by human KIRs are altered in the swine class I molecules. The amino acids responsible for binding human CD8 coreceptor are largely conserved although there are two critical residues substituted. A functional test indicated that the human T cells specific for the prokaryotically expressed SLA Plprotein could respond quite well in vitro to the class I-positive swine chon-drocytes and PBMCs in presence of human APCs. This implies that, due to the substitution of two critical residues, the inaccessibility of human CD8 coreceptor to swine class I molecule might be contributable to the indirect pathway that the human T cells have to use for recognizing the SLA class I xenogeneic antigens.展开更多
AIM： To examine an association between the cytotoxic Tlymphocyte antigen 4 （CTLA4） gene that plays a role in downregulation of T-cell activation and inflammatory bowel disease consisting of ulcerative colitis （UC...AIM： To examine an association between the cytotoxic Tlymphocyte antigen 4 （CTLA4） gene that plays a role in downregulation of T-cell activation and inflammatory bowel disease consisting of ulcerative colitis （UC） and Crohn＇s disease （CD） in the Japanese.METHODS： We studied 108 patients with UC, 79 patients with CD, and 200 sex-matched healthy controls, with respect to three single nucleotide polymorphisms （SNPs） in CTLA4, such as C-318T in the promoter region, A＋49 Gin exon 1 and G＋6230A in the 3＇ untranslated region （3＇-UTR） by a PCR-restriction fragment length polymorphism method, and to an （AT）, repeat polymorphism in 3＇-UTR by fragment analysis with fluorescence-labeling on denaturing sequence gels. Frequency of alleles and genotypes and their distribution were compared statistically between patients and controls and among subgroups of patients, using X^2 and Fisher exact tests.RESULTS： The frequency of ＂A/A＂ genotype at the G＋6230A SNP site was statistically lower in UC patients than in controls （3.7% vs 11.0%, P = 0.047, odds ratio （OR） = 0.311）. Moreover, the frequency of ＂G/G＂ genotype at the A＋49G SNP site was significantly higher in CD patients with fistula （48.6%） than those without it （26.2%）（P = 0.0388, OR=2.67）.CONCLUSION： The results suggest that CTLA4 located at 2q33 is a determinant of UC and responsible for fistula formation in CD in the Japanese.展开更多
AIM： To determine the association between the HLADRB1 alleles and perinuclear anti-neutrophil cytoplasmatic antibodies （p-ANCA） positive in Mexican patients with ulcerative colitis （UC）. METHODS： Ninety Mexican ...AIM： To determine the association between the HLADRB1 alleles and perinuclear anti-neutrophil cytoplasmatic antibodies （p-ANCA） positive in Mexican patients with ulcerative colitis （UC）. METHODS： Ninety Mexican mestizo patients （45 females） with UC, confirmed by biopsy, were studied. High resolution HLA typing was performed by PCR-SSO reverse dot blot and PCR-SSP. Molecular typing techniques were applied to define HLA-DRB1 alleles. Enzyme-linked immunosorbent assay and immunofluorescence techniques were used to detect p-ANCA. RESULTS： Forty-eight （53%） UC patients were positive for p-ANCA by ELISA and IF. We found that p-ANCA- positive UC patients had a significantly increased frequency of HLA-DR7 compared with p-ANCA-negative controls （22% vs 5.1%; pC=0.02, OR=5.2, CI 95%： 1.06-37.82）. Disease activity was scored as severe in 20 patients, moderate in 8, mild in 14 and no activity in the remaining 38 patients according to the Truelove and Witts criteria. Subgroup analysis showed a significantly increased frequency of the HLA-DRB1＊07 allele in 15 of 20 UC patients with severe activity of UC and p-ANCA positivity [100% vs 0%; pC=0.0000001; OR=35]. No significant differences were found between p-ANCA positive patients, HLA-DR alleles and other clinical features such as extraintestinal manifestations, proctocolectomy and extension.CONCLUSION： The HLA-DRB1＊07 is associated with p-ANCA positive UC Mexican patients.展开更多
文摘A total of 28 accessions of rice (Oryza sativa L.) germplasms were collected from International Rice Research Institute (IRRI), Philippine and Gene Pool of China National Rice Research Institute (CNRRI). These germplasms were attributed as a Donor Gene Pool, consisting of 27 diverse morphological marker lines with each having a unique valuable trait (gene), and the recurrent parent-Zhefu 802, an early-season indica cultivar in south of China in the 1980s and 1990s. A set of 27 isogenic lines with 2-3 markers on every chromosome were obtained after more than 10 successive backcrosses. Moreover, 15 accessions of double-marker isogenic lines were developed by further pyramiding markers on the same chromosome. Key agronomic traits such as heading date, plant height, tillering number and panicle length in this set of lines were similar to that of Zhefu 802 except the marker traits.
基金Supported by Jiangsu High-tech projects(BG2007322) "Good feature of new varieties of Silkworm BreedingPh.D., University of Jiangsu Science and Technology Fund~~
文摘[Objective] The study aimed to provide theoretical basis for development and application of molecular marker breeding technique to obtain Bombyx mori near-isogenic lines （NILs）. [Method] Thermotolerance gene was introduced into sensitive variety Ou17 by developing NILs and recurrent backcross,then through six generations of backcross,thermotolerance-assisted selection,and two generations of self-cross. [Result] Bombyx mori NILs carrying thermotolerance gene （new germplasm） were produced. Meanwhile,thermotolerance level of progenies of each backcross and molecular markers of NILs were determined,and then attempts were made to produce practical thermotolerance hybrids by using thermotolerance varieties whose thermotolerance gene is linked to SSR markers. [Conclusion] The study successfully construct thermotolerance NILs,monitor thermotolerance level and breeding results of progenies of each backcross,and determine molecular marker of NILs.
文摘Based on both cDNA sequence of barley powdery mildew resistance control element Mlo and DNA sequence of the known putative disease resistance gene from Triticum monococcum L., we designed some primers to amplify resistant homologous sequences in the near isogenic lines (NILs) of powdery mildew resistance using RT-PCR method. Two expressed cDNA fragments were isolated from wheat genome. One showed 83% homology to the Mlo gene of barley. The other contained two possible open reading frames (ORFs). NBS conservative domains 2, 3 of disease resistance gene and 13 LRR structures similar to rice Pib protein terminal were found respectively in the two ORFs. It indicated that the latter fragment belongs to NBS-LRR-like genes. The obvious difference of RT-PCR products was observed between the before challenged and the challenged for 72 h by Blumeria graminis f. sp. tritici, which, implied that this sequence could be associated with disease resistance of wheat. Using nulli-tetrasomic lines of 'Chinese Spring', the NBS-LRR-like gene had been located on chromosome 1D.
文摘In this study,silkworm strain T6,tolerant to fluoride,and silkworm strain 733xin,highly sensitive to fluoride,were used to construct the near-isogenic lines.300 random primers were used in RAPD amplification to DNAs of these lines.A molecular marker named S207 was found linked to the fluoride tolerance gene.Examination to F 2 segregated individuals of the above lines verified that this molecular marker was reliable.Subsequently,the molecular marker was cloned into a T vector (pUCm-T) for sequencing.Comparing with sequences available in the GenBank showed that this molecular marker was novel.We plan to convert it into a SCAR marker to facilitate establishment of a molecular marker assisted breeding system.
基金This work was supported by the National Natural Science Foundation of China (No. 30571142), the 948 Project from the Ministry of Agricultue (No. 2004-Z24), Jiangsu Province High Technology Foundation (No. BG2004303), the Key Technology of Agricultural Structural Adjustment (No. 05-01-05B) and PCSIRT.
文摘USSR5, a japonica rice variety from the former Soviet Union, is an extremely early maturing rice variety. To elucidate the genetic basis for its early heading, genetic analysis was carried out by crossing it with a set of major gene nearly isogenic lines （NIL） and QTL-isogenic lines. The early heading of USSR5 was attributed to the presence of photoperiod-insensitive alleles at E1 and Se-1 gene, the photoperiod-sensitive inhibitor gene i-Se-1, and the dominant earliness gene Ef-1. Analysis of a backcrossed population （BCIF1） derived from the cross USSR5 x N22 indicated that two quantitative trait loci （QTL） for early heading were located on chromosomes 7 and 8, accounting for 27.4% and 11.2% of the phenotypic variance, respectively, with both early alleles originating from USSRS. From an F2 population of the same cross, early heading QTLs were detected on chromosomes 1, 2, 7, 9, and 10, with individual QTL accounting for between 4.1% and 15.4% of the phenotypic variance. Early heading alleles at four of these five QTLs originated from USSRS. A comparison of chromosomal locations suggests that one of these QTLs may be identical with the known gene Hd4 （E1）. The relationship between the other QTLs and known genes for heading date are not clear. USSR5 is a promising source for propagating earliness for the development of improved early heading rice varieties.
基金This work was supported by "948" Project of China (No. 2001-361), Chinese National Programs for High Technology Research and Development (No. 2004AA222170), and Key Project of Chinese National Programs for Fundamental Research and Develop-ment (No. G2000016103).
文摘Genetic polymorphism of the major histocompatibility complex （MHC） B-LBⅡ gene was studied by amplification of exon 2 using PCR, followed by cloning and DNA sequencing in eight indigenous Chinese chicken populations. To reveal the genetic variation of the B-LB Ⅱ gene, 37 types of patterns detected by PCR-SSCP were investigated first, which would be used to screen novel B-LB Ⅱsequences within the breeds. The types of PCR-SSCP patterns and final sequencing allowed for the identification of 31 novel MHC B-LBⅡ alleles from 30 unrelated individuals of Chinese chickens that were sampled. These are the first designators for the alleles of chicken MHC B-LBⅡ gene based on the rule of assignment for novel mammalian alleles. Sequence alignment of the 31 B-LB Ⅱ alleles revealed a total of 68 variable sites in the fragment of exon 2, of which 51 parsimony informative and 17 singleton variable sites were observed. Among the polymorphic sites, the nucleotide substitutions in the first and second positions of the codons accounted for 36.76% and 35.29%, respectively. The sequence similarities between the alleles were estimated to be 90.6%-99.5%. The relative frequencies of synonymous and nonsynonymous nucleotide substitutions within the region were 2.92%±0.94% and 14.64%±2.67%, respectively. These results indicated that the genetic variation within exon 2 appeared to have largely arisen by gene recombination and balancing selection. Alignment of the deduced amino acid sequences of the β1 domain coded by exon 2 revealed 6 synonymous mutations and 27 nonsynonymous substitutions at the 33 disparate sites. In particular, the nonsynonymous substitutions at the putative peptide-binding sites are considered to be associated with immunological specificity of MHC B-LB Ⅱ molecule in Chinese native chickens. These results can provide a molecular biological basis for the study of disease resistance in chicken breeding.
基金Supported by Research Project from Education Department of Guangxi(200807MS065)Mathematical Modeling in Population Genetics from Talents Scheme of Universities in Guangxi~~
文摘This paper studies the offspring＇s genotype frequency of the selfing population on multiple alleles with limited loci.A recursive algorithm is given for it.It is discovered that the genotype frequency of homozygous gene of limited loci increases by generations.Relative increment reduces by generations and the genotype frequency tends to a definite value finally.The genotype frequency of limited loci with hybrid gene tends to 0 finally.But it is possibility that the genotype frequency increases in previous generations then reduces later.It is found that the number of the hybrid gene are more,the speeds tending to 0 are quicker.
基金Supported by National Natural Science Foundation of China(31101551)Yunnan Provincial Natural Science Foundation(2010CD057)Special Fund for Agro-scientific Research in the Public Interest(201003029)~~
文摘[Objective] The study aimed to explore the method for directional breeding of a male-sterile line in oval-ecotype Chinese cabbage. [Method] Based on ＂Multiple Allele Hypothesis of Genic Male Sterile Chinese Cabbage＂, an inbred line ＇06048＇ of oval ecotype was used as the receptor, and male fertile plant of ＇AB12＇ was used as the donor line. Crossing, backcross, selfing, testcross and sibling were ap- plied to transfer the multiple alleles under the directional genetic model. [Result] Segregation ratio of every generation was consistent with theoretical value. A new male sterile line with 100% male sterility and ＇06048＇ horticultural traits was ob- tained successfully, which accomplished the transfer of male sterile multiple allele and horticultural characters of receptor line at the same time. [Conclusion] The re- search verifies that the model of directional transfer is feasible, provides a theoreti- cal basis for the directional transfer of Chinese cabbage with other horticultural traits whose genotype is msms. The model can also be applied to other Brassica crops, to generate genetic male sterile lines with specific botanical traits and high-quality economic traits.
基金Supported by National Natural Science Foundation of China(30760117)National Key Technology R &D Program (2007BAD68B01)~~
文摘[ Objective] This study was to breed rice cultivars with multi-resistance to Orseolia oryzae （Wood-Mason）. [ Method] The Guangxi local cultivar GX-M001 （Jiangchao） with high resistance to Orseolia oryzae （Wood-Mason） was used to hybrid with the known resistance cultivars ＂Kangwenqingzhan＂ （harboring GM5 gene）, OB677（ harboring GM3 gene） from Sri Lanka, HT1350 and high yield end quality cultivar ＂ Guiruanzhan＂. [ Result] Through pyramiding the multi-resistant genes via routine hybridization, the general resistances of the hybrids were remarkably enhanced. The grades of resistance were also improved, many of the combinations were endowed with a resistance at immune level （grade 0） ; and interestingly, the respective hybridization of GX-M001 （high resistance） with OB677（ medium resistance） and HT1350（suscepti- ble） also generate two lines at immune level, which is probably the effects of additive effects of genes.[ Conclusion] By routine hybridization, multiple genes were successfully pyramided, thus generating novel rice lines with multiple resistances. For the rice breeding scientists at the grass-roots level, the resistance-resistance pyramiding is an effective approach to breed high resistance cultivars.
基金the National Basic Research Development Program of China (No. 2006cb500706)the National Natural Science Foundation of China (No. 30700251)+1 种基金Shanghai Key Project of Basic Science Research (No. 04DZ14005)the Program for Outstanding Medical Academic Leader (No. LJ 06003).
文摘Inflammation has been shown to play an important role in the progression of Alzheimer＇s disease （AD）. Recent epidemical study indicates that the incidence of AD in some populations is substantially influenced by the gene polymorphisms of the inflammation mediators. Meanwhile, an ensured risk factor, the ApoE ε4 allele is also reported to directly promote inflammation. Accordingly, it appears that an individual genetic background has partly determined his predisposition for AD by the extent of the inflammation response to the chronic stimulus by β-amyloid peptide （Aβ） deposits and other antigen stressor in the elderly. Hence we present a hypothesis that the inflammation genotypes may contribute to AD susceptibility. This may provide a new orientation both for future identification of individuals at risk and for personalized medication.
基金This project was supported by "the Hundred Leading Scientists Program of the Public Health Sector of Shanghai " (No. 98BR007), and "the National Science Foundation of China" (No. 30370645).
文摘Objective: To study the features of microsatellite alterations on chromosome 8 and their asso- ciation with clinicopathological characteristics of hepatocellular carcinoma (HCC). Methods: Ten highly- polymorphic microsatellite markers on chromosome 8 were selected to be detected for loss of heterozygosity (LOH), microsatellite instability (MSI) and allelic imbalance (AI) in 56 HCC using MegaBACE 500 auto- matic DNA analysis system. Results: LOH was found in 37 of 56 HCC (66.1%) on at least 1 locus, and the top three loci were D8S261(53.5%), D8S1721(52.5%) and D8S1771(52.5%). LOH frequency on D8S277 was signi?cantly higher in cases positive for serum HBsAg than in those negative for HBsAg (P <0.01). Similarly, LOH on D8S261, D8S298 and D8S1733 occurred more frequently in patients with negative HB- sAg than those with positive HBsAg (P <0.01). LOH on D8S298 and D8S1771 was more frequent in those tumors larger than 3 cm in size (P <0.05 or P <0.01). LOH frequencies of D8S1721 were signi?cantly higher in the patients with absent or not intact tumor capsule than in those with intact tumor capsule (P <0.05). LOH on D8S298 and D8S1771 was more frequently detected in tumors with intrahepatic metastasis than in those without intrahepatic metastasis (P <0.01). MSI was found in 12.5% (7/56) cases, and AI was found in 19.6% (11/56), no correlation was found between MSI and AI and clinicopathological character- istics of HCC. Conclusion: Frequent microsatellite alterations on chromosome 8 existed in HCC. LOH, which represents tumor suppressor gene pathway, plays a more important role in hepatocarcinogenesis; MSI representing mismatch repair gene pathway ranks next. LOH at a particula locus is associated with the clinicopathological parameters of human HCC.
文摘The study aims at exploring the possibility of using the recovery ability af- ter drought stress-rewatering at vegetative growth stage as the evaluating index in water use efficiency （WUE） of winter wheat varieties. ＇Jing 411 ＇, ＇Jinmai 47＇ and their 34 near isogenic lines （NILs） were used as test materials. Semi-automatic rainproof shelter and the percolating pools were used for simulating drought treat- ment. After suffering severe drought stress, winter wheat crops were rewatered at early jointing stage. The biomass accumulation after rewatering was determined as recovery ability index. In the meanwhile, plant height in the end of vegetative growth stage was measured, and WUE of varieties/lines was also determined. Thereafter, the differences in recovery ability, plant height and the population WUE, together with the correlation between recovery ability and population WUE were analyzed, respectively. The results showed that there were significant differences in recovery ability among some varieties/lines. The recovery ability was affected by both geno- type and environment, and the interaction existed in these two factors. Significant differences existed in plant height and population WUE among the 34 NILs along with their parents. There was a significantly positive correlation between recovery ability and plant height of varieties/lines. Recovery ability and plant height were very significantly and positively correlated with population yield WUE respectively. The re- sults indicated that recovery ability after drought stress-rewatering could be used as an evaluating index of population WUE under drought condition.
基金sponsored jointly by the Natural Science Foundation of China (No. 40206019)Agricultural Innovation Project of Nantong (No. L4017)
文摘Vertical polyamide gel electrophoresis was used to investigate isozyme polymorphisms among different isolates （including wild and cultivated） of Porphyra katadai, Porphyra oligospermatangia, Porphyra yezoensis, Porphyra haitanensis, and a hybridize species （Porphyra yezoensis x Porphyra haitanensis） sampled from China. Whereafter, the analyses of probable minimum loci numbers, observed alleles sum, genetic diversity, and unweighted pair-group arithmetic average （UPGMA） cluster were carded out. After initial activity and resolution testing of bands of 23 enzymes, 6 of them （MDH, ME, LDH, GDH, IDH and G-6-PDH） were proved to be appropriate for analysis of the full sample set. The probable minimum numbers of loci and alleles analyses showed that the five species of Porphyra had an extraordinary consistent result in ME loci and alleles. However, P. katadai and P. oligospermatangia differed from other three species of Porphyra in LDH and GDH loci and alleles. P. katadai was independent in the analyses of MDH and P. oligosperTnatangia and P. haitanensis differed from other three species in IDH analyses. Moreover, P. yezoensis and P. haitanensis were apart from other three species in G-6-PDH analysis. Taking one with another, P. katadai was relatively separated in the probable minimum numbers of loci and alleles analyses. The results indicated that the genetic variation among the five Porphyra species was limited with a genetic identity of 0.7550. The hybridize species （P. yezoensis x P. haitanensis） seemed to be high homologue with P. oligospermatangia, unexpectedly got relatively lower average genetic identities with both P. yezoensis and P. haitanensis. The 4 strains of P. yezoensis were relatively divergent with an average genetic identity of 0.7428, and P. katadai presented the most differentiated, compared with other species, which consistented with the result summarized in the probable minimum numbers of loci and alleles analyses.
基金supported by the National Science Fund for Distinguished Young Scientists (No. 30925008)the Major International (Regional) Joint Research Project (No. 31010103901)+1 种基金the CAS-IOZ Innovation Program (KSCX2-EW-J-2) by a grant (No. O529YX5105) from the Key Laboratory of the Zoological Systematics and Evolution of the Chinese Academy of Sciences to F.M. Lei
文摘Although a growing number of both sequence-based and microsatellite nuclear loci have been used to infer genetic structures, their relative efficiencies remain poorly understood. In our study, we used the Green-backed Tit (Parus monticolus) to explore the resolving ability of these two types of markers. The south-western and central mitochondrial DNA (mtDNA) phylogroups were divergent to some extent in sequence-based nuclear data, while mixed together in microsatellites data. The F ST values among clades were about four times lower in microsatellite loci than those in sequence-based nuclear loci. We are of the opinion that size homoplasy may have contributed to the inability of microsatellites to uncover differentiation. Our results suggest that sequence-based nuclear loci outperformed microsatellite loci in detecting population structures, especially those focused on populations with large effective population sizes. There was no significant correlation between F ST values and allelic size variability, which suggested that the efficiency of microsatellite loci in detecting genetic structure may be independent of their polymorphism. F ST is better than R ST in detecting intraspecific divergence due to the high variance of R ST . In agreement with sequence-based nuclear loci, microsatellite loci did resolve the genetic distinctness of the Taiwan Residents phylogroup. The genetic differentiation between the Taiwan Residents and continental clades may involve allopatric divergence without gene flow.
文摘A SIT-BJT model is proposed for static induction thyristors （SITh） operation in the blocking state. On the basis of the physical mechanism, this model is presented analytically in terms of governing equations that link the electrical parameters to the structural parameters. The model is verified by numerical simulation and theoretical analysis. Based on the model, the variations of the electrical parameters such as the potential barrier, the anode junction voltage drop, and the current amplification factor are studied and discussed.
基金Supported by grants from the Department of Biotechnology, Government of India (to PPM) and the Department of Science & Technology, Government of West Bengal (to AC)
文摘AIM： To identify the variants in U rase 1 （UGT1A1） gene in Gilbert＇s syndrome （GS） and to estimate the association between homozygosity for TA insertion and GS in India, as well as the frequency of TA insertion and its impact among normal controls in India. METHODS： Ninety-five GS cases and 95 normal controls were selected. Liver function and other tests were done. The promoter and all 5 exons of UGT1A1 gene were resequenced. Functional assessment of a novel trinucleotide insertion was done by in silico analysis and by estimating UGT1A1 promoter activity carried out by ludferase reporter assay of appropriate constructs in Hep G2 cell line. RESULTS： Among the GS patients, 80% were homozygous for the TA insertion, which was several-fold higher than reports from other ethnic groups. The mean UCB level was elevated among individuals with only one copy of this insertion, which was not significantly different from those with two copies. Many new DNA variants in UGT1A1 gene were discovered, including a trinucleotide （CAT） insertion in the promoter found in a subset （10%） of GS patients, but not among normal controls. In-silico analysis showed marked changes in the DNA-folding of the promoter and functional analysis showed a 20-fold reduction in transcription efficiency of UGT1A1 gene resulting from this insertion, thereby significantly elevating the UCB level. CONCLUSION： The genetic epidemiology of GS is variable across ethnic interactions among UGT1A1 groups and the epistatic promoter variants modulate bilirubin glucuronidation.
基金supported by the grants from National Natural Science Foundation of China(No.39993430-2,30000157)
文摘To lay background for studying rejection mechanisms in xenotransplantation and developing the strategies for intervention, class I genes of swine leukocyte antigens (SLA) of three Chinese pig strains Bm, Gz and Yn were cloned and sequenced. The cDNA of the class I loci P1 and P14 were amplified by RT-PCR and subjected to insert into sequencing vectors. All six allelic sequences we examined, each two for one Chinese strain, are not identical to those reported, which allows these novel sequences receiving their accession numbers AY102467- AY102472 from GenBank. This study further reveals that the homologies of MHC class I genes in their primary structures and the deduced amino acids between Chinese pigs (SLA) and human (HLA-A*0201) are better than those between pigs and mice (H-2Db/H-2Kb). The comparison also indicates that the amino acid residues critical for recognition by human KIRs are altered in the swine class I molecules. The amino acids responsible for binding human CD8 coreceptor are largely conserved although there are two critical residues substituted. A functional test indicated that the human T cells specific for the prokaryotically expressed SLA Plprotein could respond quite well in vitro to the class I-positive swine chon-drocytes and PBMCs in presence of human APCs. This implies that, due to the substitution of two critical residues, the inaccessibility of human CD8 coreceptor to swine class I molecule might be contributable to the indirect pathway that the human T cells have to use for recognizing the SLA class I xenogeneic antigens.
文摘AIM： To examine an association between the cytotoxic Tlymphocyte antigen 4 （CTLA4） gene that plays a role in downregulation of T-cell activation and inflammatory bowel disease consisting of ulcerative colitis （UC） and Crohn＇s disease （CD） in the Japanese.METHODS： We studied 108 patients with UC, 79 patients with CD, and 200 sex-matched healthy controls, with respect to three single nucleotide polymorphisms （SNPs） in CTLA4, such as C-318T in the promoter region, A＋49 Gin exon 1 and G＋6230A in the 3＇ untranslated region （3＇-UTR） by a PCR-restriction fragment length polymorphism method, and to an （AT）, repeat polymorphism in 3＇-UTR by fragment analysis with fluorescence-labeling on denaturing sequence gels. Frequency of alleles and genotypes and their distribution were compared statistically between patients and controls and among subgroups of patients, using X^2 and Fisher exact tests.RESULTS： The frequency of ＂A/A＂ genotype at the G＋6230A SNP site was statistically lower in UC patients than in controls （3.7% vs 11.0%, P = 0.047, odds ratio （OR） = 0.311）. Moreover, the frequency of ＂G/G＂ genotype at the A＋49G SNP site was significantly higher in CD patients with fistula （48.6%） than those without it （26.2%）（P = 0.0388, OR=2.67）.CONCLUSION： The results suggest that CTLA4 located at 2q33 is a determinant of UC and responsible for fistula formation in CD in the Japanese.
基金Supported by Consejo Nacional de Ciencia y Tecnologia CONACYT,NO. 153237
文摘AIM： To determine the association between the HLADRB1 alleles and perinuclear anti-neutrophil cytoplasmatic antibodies （p-ANCA） positive in Mexican patients with ulcerative colitis （UC）. METHODS： Ninety Mexican mestizo patients （45 females） with UC, confirmed by biopsy, were studied. High resolution HLA typing was performed by PCR-SSO reverse dot blot and PCR-SSP. Molecular typing techniques were applied to define HLA-DRB1 alleles. Enzyme-linked immunosorbent assay and immunofluorescence techniques were used to detect p-ANCA. RESULTS： Forty-eight （53%） UC patients were positive for p-ANCA by ELISA and IF. We found that p-ANCA- positive UC patients had a significantly increased frequency of HLA-DR7 compared with p-ANCA-negative controls （22% vs 5.1%; pC=0.02, OR=5.2, CI 95%： 1.06-37.82）. Disease activity was scored as severe in 20 patients, moderate in 8, mild in 14 and no activity in the remaining 38 patients according to the Truelove and Witts criteria. Subgroup analysis showed a significantly increased frequency of the HLA-DRB1＊07 allele in 15 of 20 UC patients with severe activity of UC and p-ANCA positivity [100% vs 0%; pC=0.0000001; OR=35]. No significant differences were found between p-ANCA positive patients, HLA-DR alleles and other clinical features such as extraintestinal manifestations, proctocolectomy and extension.CONCLUSION： The HLA-DRB1＊07 is associated with p-ANCA positive UC Mexican patients.
