Epigenetic marks on histones and DNA,such as DNA methylation at N6-adenine(6mA),play crucial roles in gene expression and genome maintenance,but their deposition and function in microalgae remain largely uncharacteriz...Epigenetic marks on histones and DNA,such as DNA methylation at N6-adenine(6mA),play crucial roles in gene expression and genome maintenance,but their deposition and function in microalgae remain largely uncharacterized.Here,we report a genome-wide 6mA map for the model industrial oleaginous microalga Nannochloropsis oceanica produced by single-molecule real-time sequencing.Found in 0.1%of adenines,6mA sites are mostly enriched at the AGGYV motif,more abundant in transposons and 30 untranslated re-gions,and associated with active transcription.Moreover,6mA gradually increases in abundance along the direction of gene transcription and shows special positional enrichment near splicing donor and transcrip-tion termination sites.Highly expressed genes tend to show greater 6mA abundance in the gene body than do poorly expressed genes,indicating a positive interaction between 6mA and general transcription fac-tors.Furthermore,knockout of the putative 6mA methylase NO08G00280 by genome editing leads to changes in methylation patterns that are correlated with changes in the expression of molybdenum cofactor,sulfate transporter,glycosyl transferase,and lipase genes that underlie reductions in biomass and oil productivity.By contrast,knockout of the candidate demethylase NO06G02500 results in increased 6mA levels and reduced growth.Unraveling the epigenomic players and their roles in biomass productivity and lipid metabolism lays a foundation for epigenetic engineering of industrial microalgae.展开更多
The urinary concentrations of hydroxyproline (HYPRO)and 3 -methyl histidine (3 - MEHIS) were de- termined in 16 Chinese-Holstein cows. The objectives of the experiment were to find out thhe relationship between collag...The urinary concentrations of hydroxyproline (HYPRO)and 3 -methyl histidine (3 - MEHIS) were de- termined in 16 Chinese-Holstein cows. The objectives of the experiment were to find out thhe relationship between collagen and myosin ddegradation and uterine involution in the postpartum cow. The results in the experiment showed that the mean concentrations of HYPRO and 3-MEHIS were 138.32±22.99 and 37.09 ±3.90 nmol·mL-1,respectively,for the cows during the days between 60-90 postpartum,and for the cows immediately after calving the concentrations of HYPRO and 3 -MEHIS reduced from 284.30 and 65.48 nmol ·mL-1 on the day one after calving to the normal level of 109.18 and 33.51 nmol·mL^-1 on the day 50 post- partum,respectively. There was a good correlation between the urinary concentrations of both HYPRO and 3 -MEHIS and the diameters of the involuting uterus (r = 0. 79).展开更多
The increases of fresh weight, chlorophyll and protein content of detached etiolated cotyledons of Brissica chinensis under illumination were promoted by 140 μmol/L NdCl 3 treatment. The content of isopentenyl adeni...The increases of fresh weight, chlorophyll and protein content of detached etiolated cotyledons of Brissica chinensis under illumination were promoted by 140 μmol/L NdCl 3 treatment. The content of isopentenyl adenine( i PA) of the control determination with ELISA remained unchanged at 12 h. At 24 h, it increased to 70 pmol/g·FW. At 36 h, it was 87 pmol/g·FW, and at 48 h, it declined to 20 pmol/g·FW. Contrary, the content of i PA of cotyledons treated with NdCl 3 for 12 h increased to 15 pmol/g·FW. For 24 h, it was 148 pmol/g·FW, and maintained a high level between 24 h and 48 h. These results indicate that NdCl 3 promotes i PA synthesis in detached etiolated cotyledons of Brassica chinensis.展开更多
基金supported by the Synthetic Biology Program of the Ministry of Science and Technology of the People’s Republic of China (2021YFA0909700)I201908 and E1551402 from the Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences,31900071 from the Natural Science Foundation of ChinaZR2019QC012 from the Natural Science Foundation of Shandong Province.
文摘Epigenetic marks on histones and DNA,such as DNA methylation at N6-adenine(6mA),play crucial roles in gene expression and genome maintenance,but their deposition and function in microalgae remain largely uncharacterized.Here,we report a genome-wide 6mA map for the model industrial oleaginous microalga Nannochloropsis oceanica produced by single-molecule real-time sequencing.Found in 0.1%of adenines,6mA sites are mostly enriched at the AGGYV motif,more abundant in transposons and 30 untranslated re-gions,and associated with active transcription.Moreover,6mA gradually increases in abundance along the direction of gene transcription and shows special positional enrichment near splicing donor and transcrip-tion termination sites.Highly expressed genes tend to show greater 6mA abundance in the gene body than do poorly expressed genes,indicating a positive interaction between 6mA and general transcription fac-tors.Furthermore,knockout of the putative 6mA methylase NO08G00280 by genome editing leads to changes in methylation patterns that are correlated with changes in the expression of molybdenum cofactor,sulfate transporter,glycosyl transferase,and lipase genes that underlie reductions in biomass and oil productivity.By contrast,knockout of the candidate demethylase NO06G02500 results in increased 6mA levels and reduced growth.Unraveling the epigenomic players and their roles in biomass productivity and lipid metabolism lays a foundation for epigenetic engineering of industrial microalgae.
基金supported financially by Heilongjiang(C- 9702)and Chinese National (39870572)Natural and Scicntificfunds.
文摘The urinary concentrations of hydroxyproline (HYPRO)and 3 -methyl histidine (3 - MEHIS) were de- termined in 16 Chinese-Holstein cows. The objectives of the experiment were to find out thhe relationship between collagen and myosin ddegradation and uterine involution in the postpartum cow. The results in the experiment showed that the mean concentrations of HYPRO and 3-MEHIS were 138.32±22.99 and 37.09 ±3.90 nmol·mL-1,respectively,for the cows during the days between 60-90 postpartum,and for the cows immediately after calving the concentrations of HYPRO and 3 -MEHIS reduced from 284.30 and 65.48 nmol ·mL-1 on the day one after calving to the normal level of 109.18 and 33.51 nmol·mL^-1 on the day 50 post- partum,respectively. There was a good correlation between the urinary concentrations of both HYPRO and 3 -MEHIS and the diameters of the involuting uterus (r = 0. 79).
文摘The increases of fresh weight, chlorophyll and protein content of detached etiolated cotyledons of Brissica chinensis under illumination were promoted by 140 μmol/L NdCl 3 treatment. The content of isopentenyl adenine( i PA) of the control determination with ELISA remained unchanged at 12 h. At 24 h, it increased to 70 pmol/g·FW. At 36 h, it was 87 pmol/g·FW, and at 48 h, it declined to 20 pmol/g·FW. Contrary, the content of i PA of cotyledons treated with NdCl 3 for 12 h increased to 15 pmol/g·FW. For 24 h, it was 148 pmol/g·FW, and maintained a high level between 24 h and 48 h. These results indicate that NdCl 3 promotes i PA synthesis in detached etiolated cotyledons of Brassica chinensis.
