目的:提高草原兔尾鼠(L agurus lagurus)卵透明带3(LZP 3)基因在酵母细胞中表达的水平.方法:利用重叠PCR技术,定点突变LZP 3基因上6个稀有的密码子簇,将LZP 3基因中11个稀有的密码子更换成毕赤酵母(P ich ia Pastoris)最常用的相应密码...目的:提高草原兔尾鼠(L agurus lagurus)卵透明带3(LZP 3)基因在酵母细胞中表达的水平.方法:利用重叠PCR技术,定点突变LZP 3基因上6个稀有的密码子簇,将LZP 3基因中11个稀有的密码子更换成毕赤酵母(P ich ia Pastoris)最常用的相应密码子.将获得的LZP 3突变基因(LZP 3m)插入pGAPZαA中,构建穿梭表达载体.以重组体转化P ich ia Pastoris SM D 1168菌株进行表达.结果:LZP 3m基因的表达量比野生型LZP 3基因明显提高.结论:通过密码子优化,能显著提高LZP 3基因在酵母细胞中的表达水平.展开更多
Arbuscular mycorrhizal fungi(AMF)are plant root symbionts that play key roles in plant growth and soil fertility.They are obligate biotrophic fungi that form coenocytic multinucleated hyphae and spores.Numerous studie...Arbuscular mycorrhizal fungi(AMF)are plant root symbionts that play key roles in plant growth and soil fertility.They are obligate biotrophic fungi that form coenocytic multinucleated hyphae and spores.Numerous studies have shown that diverse microorganisms live on the surface of and inside their mycelia,resulting in a metagenome when whole-genome sequencing(WGS)data are obtained from sequencing AMF cultivated in vivo.The metagenome contains not only the AMF sequences,but also those from associated microorganisms.In this study,we introduce a novel bioinformatics program,Spore-associated Symbiotic Microbes(SeSaMe),designed for taxonomic classification of short sequences obtained by next-generation DNA sequencing.A genus-specific usage bias database was created based on amino acid usage and codon usage of a three consecutive codon DNA 9-mer encoding an amino acid trimer in a protein secondary structure.The program distinguishes between coding sequence(CDS)and non-CDS,and classifies a query sequence into a genus group out of 54 genera used as reference.The mean percentages of correct predictions of the CDS and the non-CDS test sets at the genus level were 71% and 50% for bacteria,68% and 73% for fungi(excluding AMF),and 49% and 72% for AMF(Rhizophagus irregularis),respectively.SeSaMe provides not only a means for estimating taxonomic diversity and abundance but also the gene reservoir of the reference taxonomic groups associated with AMF.Therefore,it enables users to study the symbiotic roles of associated microorganisms.It can also be applicable to other microorganisms as well as soil metagenomes.SeSaMe is freely available at www.fungalsesame.org.展开更多
文摘目的:提高草原兔尾鼠(L agurus lagurus)卵透明带3(LZP 3)基因在酵母细胞中表达的水平.方法:利用重叠PCR技术,定点突变LZP 3基因上6个稀有的密码子簇,将LZP 3基因中11个稀有的密码子更换成毕赤酵母(P ich ia Pastoris)最常用的相应密码子.将获得的LZP 3突变基因(LZP 3m)插入pGAPZαA中,构建穿梭表达载体.以重组体转化P ich ia Pastoris SM D 1168菌株进行表达.结果:LZP 3m基因的表达量比野生型LZP 3基因明显提高.结论:通过密码子优化,能显著提高LZP 3基因在酵母细胞中的表达水平.
文摘Arbuscular mycorrhizal fungi(AMF)are plant root symbionts that play key roles in plant growth and soil fertility.They are obligate biotrophic fungi that form coenocytic multinucleated hyphae and spores.Numerous studies have shown that diverse microorganisms live on the surface of and inside their mycelia,resulting in a metagenome when whole-genome sequencing(WGS)data are obtained from sequencing AMF cultivated in vivo.The metagenome contains not only the AMF sequences,but also those from associated microorganisms.In this study,we introduce a novel bioinformatics program,Spore-associated Symbiotic Microbes(SeSaMe),designed for taxonomic classification of short sequences obtained by next-generation DNA sequencing.A genus-specific usage bias database was created based on amino acid usage and codon usage of a three consecutive codon DNA 9-mer encoding an amino acid trimer in a protein secondary structure.The program distinguishes between coding sequence(CDS)and non-CDS,and classifies a query sequence into a genus group out of 54 genera used as reference.The mean percentages of correct predictions of the CDS and the non-CDS test sets at the genus level were 71% and 50% for bacteria,68% and 73% for fungi(excluding AMF),and 49% and 72% for AMF(Rhizophagus irregularis),respectively.SeSaMe provides not only a means for estimating taxonomic diversity and abundance but also the gene reservoir of the reference taxonomic groups associated with AMF.Therefore,it enables users to study the symbiotic roles of associated microorganisms.It can also be applicable to other microorganisms as well as soil metagenomes.SeSaMe is freely available at www.fungalsesame.org.
