The mechanisms of sexual development and regulation display extraordinary diversity between phyla. However, recent studies show that there must be underlying evolutionary conservatism between different mechanisms. In ...The mechanisms of sexual development and regulation display extraordinary diversity between phyla. However, recent studies show that there must be underlying evolutionary conservatism between different mechanisms. In order to examine evolutionary conservatism in molecular mechanisms of sex determination, the natural sex reversal process of the rice field eel (Monopterus albus) was used to identify conserved functional genes involved in sex determination and differentiation. Firstly, a mini cDNA library was constructed from the cDNAs expressed specifically in the human testis. The cDNA library was screened with first strand cDNA probes from the intersex gonads of rice field eels. Secondly, likely positive clones were arrayed onto two nylon membranes, which were then hybridized with the first strand cDNAs probes from rice field eel intersex and female gonads respectively. Two positive clones were obtained, which showed obvious differential expression between intersex and female gonads. DNA sequencing analysis reveal that the insert fragments of these two clones were 895 bp and 596 bp long respectively. BLAST results indicate that the 895 bp fragment is the 3′ part of the No.AJ011779 gene, located on 6q21, encoding a homologue of yeast Sec63p protein. An interesting finding is that one member of the human Sec gene family, Sec61γ , is expressed in the testis and involved in the process of testis development. The 596 bp fragment was 97% identical with the No.BG723880 EST, located on clone RP11 12M5 of chromosome 1 This needs further study. We infer that these two genes should also play a role in sexual development.展开更多
印度甘地水产养殖中心（Rajiv Gandhi Centre for Aquaculture；RGCA）在印度安得拉邦Krishna区Konathanapadu所进行之虾种开发计划。2011年4月首度成功发展出新雌性成虾（neofemales）并取得巨型淡水虾种苗（罗氏沼虾：Macrobrachium r...印度甘地水产养殖中心（Rajiv Gandhi Centre for Aquaculture；RGCA）在印度安得拉邦Krishna区Konathanapadu所进行之虾种开发计划。2011年4月首度成功发展出新雌性成虾（neofemales）并取得巨型淡水虾种苗（罗氏沼虾：Macrobrachium rosenbergii）。RGCA所开发之技术为将健康雄虾透过复杂的性别逆转为雌性成虾（neofemales），运用显微外科干预及雌虾与标准雄虾杂交产生皆为雄虾之种苗。此项技术未涉及任何基因操纵或贺尔蒙治疗，可让单位面积产能增加约40％，重振印度国内养殖业，解决淡水虾养殖业面临的雌、雄虾差异的生长方式、存活率低、产量贫乏等挑战。展开更多
文摘The mechanisms of sexual development and regulation display extraordinary diversity between phyla. However, recent studies show that there must be underlying evolutionary conservatism between different mechanisms. In order to examine evolutionary conservatism in molecular mechanisms of sex determination, the natural sex reversal process of the rice field eel (Monopterus albus) was used to identify conserved functional genes involved in sex determination and differentiation. Firstly, a mini cDNA library was constructed from the cDNAs expressed specifically in the human testis. The cDNA library was screened with first strand cDNA probes from the intersex gonads of rice field eels. Secondly, likely positive clones were arrayed onto two nylon membranes, which were then hybridized with the first strand cDNAs probes from rice field eel intersex and female gonads respectively. Two positive clones were obtained, which showed obvious differential expression between intersex and female gonads. DNA sequencing analysis reveal that the insert fragments of these two clones were 895 bp and 596 bp long respectively. BLAST results indicate that the 895 bp fragment is the 3′ part of the No.AJ011779 gene, located on 6q21, encoding a homologue of yeast Sec63p protein. An interesting finding is that one member of the human Sec gene family, Sec61γ , is expressed in the testis and involved in the process of testis development. The 596 bp fragment was 97% identical with the No.BG723880 EST, located on clone RP11 12M5 of chromosome 1 This needs further study. We infer that these two genes should also play a role in sexual development.
文摘印度甘地水产养殖中心（Rajiv Gandhi Centre for Aquaculture；RGCA）在印度安得拉邦Krishna区Konathanapadu所进行之虾种开发计划。2011年4月首度成功发展出新雌性成虾（neofemales）并取得巨型淡水虾种苗（罗氏沼虾：Macrobrachium rosenbergii）。RGCA所开发之技术为将健康雄虾透过复杂的性别逆转为雌性成虾（neofemales），运用显微外科干预及雌虾与标准雄虾杂交产生皆为雄虾之种苗。此项技术未涉及任何基因操纵或贺尔蒙治疗，可让单位面积产能增加约40％，重振印度国内养殖业，解决淡水虾养殖业面临的雌、雄虾差异的生长方式、存活率低、产量贫乏等挑战。
