Plants have developed many signals and specific genes＇ regulations at both transcriptional and post-transcriptional levels in order to tolerate and adapt to various environmental stresses. RNA-binding proteins （RBPs...Plants have developed many signals and specific genes＇ regulations at both transcriptional and post-transcriptional levels in order to tolerate and adapt to various environmental stresses. RNA-binding proteins （RBPs） play crucial roles in the post- transcriptional regulation via mRNA splicing, polyadenylation, sequence editing, transport, mRNA stability, mRNA localization, and translation. In this paper, four cDNAs of glycine-rich RNA-binding proteins （GR-RBPs）, named NtRGP-la, -lb, -2, and -3, were isolated from Nicotiana tabacum by RT-PCR analysis, and special emphases were given to the sequences alignment, phylogenetic analysis and gene expression. Sequences alignment revealed minor difference of cDNA sequences, but no difference of deduced proteins between N. sylvestris and N. tabacum. Phylogenetic alignment revealed that four cDNAs in tobacco were clustered into two different groups. NtRGP-2 and -3 were evolutionarily closest to Arabidopsis GR-RBPs genes and related to animal GR-RBPs genes, while NtRGP-la and -lb were closest to Gramineae GR-RBPs genes. The expression analyses of these four NtRGPs in response to different abiotic stresses revealed the similar expression pattern. Moreover, the four NtRGPs, especially NtRGP-la and NtRGP-3, were strongly induced by stresses including water, wound, cold, and high temperature, weakly induced by PEG, drought and SA, while reduced by NaC1 and unaffected by ABA treatment. The fact that all of these abiotic stresses included in our experiments affected the water balance and resulted in osmotic stress on cellular level, suggests that NtRGPs in tobacco should be a family of crucial osmosis-related proteins, and may play a key role in signal transduction with ABA-independent pathway under abiotic stresses.展开更多
Background Cervical keratinocytes are recovered at a low numbers and frequently associated with contaminating human fibroblasts which rapidly overgrow the epithelial cells in culture with medium supplemented with 10% ...Background Cervical keratinocytes are recovered at a low numbers and frequently associated with contaminating human fibroblasts which rapidly overgrow the epithelial cells in culture with medium supplemented with 10% fetal bovine serum （FBS）. However, it is difficult to initiate keratinocyte cultures with serum-free keratinocyte growth medium alone because cell attachment can be poor. Therefore, the culture of these cells is extremely difficult. In this study, we described a modified culture medium and coated culture plastics for growing normal human cervical epithelial cells in vitro. Methods Normal cervical epithelial tissue pieces were obtained and digested with type I collagenase to dissociate the cells and a single cell suspension produced. The cells were cultured on plastic tissue culture substrate alone or substrate coated with collagen type I from rat tail, with modified keratinocyte serum-free medium （K-SFM） supplemented with 5% FBS. After attachment, the medium were replaced with K-SFM without FBS. The expression of basal keratins of the ectocervical epithelium, K5, K14 and K19 were assayed by immunofluorescence with monoclonal antibodies to identify the cell purity. Results Our results indicate that cells attached to the culture plastic more quickly in K-SFM supplemented with 5% FBS than in K-SFM alone, as well as to tissue culture plastic coated with collagen type I than plastic alone. The modified medium composed of K-SFM and 5% FBS combined with a specific tissue culture plastic coated with collagen type I from rat tail was the best method for culture of normal cervical epithelial cells. K5, K14 and K19 were assayed and keratinocyte purity was nearly 100%. Conclusion A novel, simple and effective method can be used to rapidly obtain highly purified keratinocytes from normal human cervical epithelium.展开更多
基金funded by the National Natural Science Foundation of China (30560062)the Natural Science Foundation of Yunnan Province, China (2003C0342M)the Science-Technology Foundation of Tobacco Company of Yunnan Province, China (06A02)
文摘Plants have developed many signals and specific genes＇ regulations at both transcriptional and post-transcriptional levels in order to tolerate and adapt to various environmental stresses. RNA-binding proteins （RBPs） play crucial roles in the post- transcriptional regulation via mRNA splicing, polyadenylation, sequence editing, transport, mRNA stability, mRNA localization, and translation. In this paper, four cDNAs of glycine-rich RNA-binding proteins （GR-RBPs）, named NtRGP-la, -lb, -2, and -3, were isolated from Nicotiana tabacum by RT-PCR analysis, and special emphases were given to the sequences alignment, phylogenetic analysis and gene expression. Sequences alignment revealed minor difference of cDNA sequences, but no difference of deduced proteins between N. sylvestris and N. tabacum. Phylogenetic alignment revealed that four cDNAs in tobacco were clustered into two different groups. NtRGP-2 and -3 were evolutionarily closest to Arabidopsis GR-RBPs genes and related to animal GR-RBPs genes, while NtRGP-la and -lb were closest to Gramineae GR-RBPs genes. The expression analyses of these four NtRGPs in response to different abiotic stresses revealed the similar expression pattern. Moreover, the four NtRGPs, especially NtRGP-la and NtRGP-3, were strongly induced by stresses including water, wound, cold, and high temperature, weakly induced by PEG, drought and SA, while reduced by NaC1 and unaffected by ABA treatment. The fact that all of these abiotic stresses included in our experiments affected the water balance and resulted in osmotic stress on cellular level, suggests that NtRGPs in tobacco should be a family of crucial osmosis-related proteins, and may play a key role in signal transduction with ABA-independent pathway under abiotic stresses.
基金This study was supported by a grant from the National Natural Science Foundation of China （No. 81072122）.
文摘Background Cervical keratinocytes are recovered at a low numbers and frequently associated with contaminating human fibroblasts which rapidly overgrow the epithelial cells in culture with medium supplemented with 10% fetal bovine serum （FBS）. However, it is difficult to initiate keratinocyte cultures with serum-free keratinocyte growth medium alone because cell attachment can be poor. Therefore, the culture of these cells is extremely difficult. In this study, we described a modified culture medium and coated culture plastics for growing normal human cervical epithelial cells in vitro. Methods Normal cervical epithelial tissue pieces were obtained and digested with type I collagenase to dissociate the cells and a single cell suspension produced. The cells were cultured on plastic tissue culture substrate alone or substrate coated with collagen type I from rat tail, with modified keratinocyte serum-free medium （K-SFM） supplemented with 5% FBS. After attachment, the medium were replaced with K-SFM without FBS. The expression of basal keratins of the ectocervical epithelium, K5, K14 and K19 were assayed by immunofluorescence with monoclonal antibodies to identify the cell purity. Results Our results indicate that cells attached to the culture plastic more quickly in K-SFM supplemented with 5% FBS than in K-SFM alone, as well as to tissue culture plastic coated with collagen type I than plastic alone. The modified medium composed of K-SFM and 5% FBS combined with a specific tissue culture plastic coated with collagen type I from rat tail was the best method for culture of normal cervical epithelial cells. K5, K14 and K19 were assayed and keratinocyte purity was nearly 100%. Conclusion A novel, simple and effective method can be used to rapidly obtain highly purified keratinocytes from normal human cervical epithelium.
