为研究减数分裂相关基因Spo11(meiotic protein covalently bound to DSB homolog)在罗氏沼虾(Macrobrachium rosenbergii)卵巢发育中的调控作用,采用RACE技术、荧光定量PCR、原位杂交和RNA干扰等方法,对罗氏沼虾Spo11基因(MrSpo11)及...为研究减数分裂相关基因Spo11(meiotic protein covalently bound to DSB homolog)在罗氏沼虾(Macrobrachium rosenbergii)卵巢发育中的调控作用,采用RACE技术、荧光定量PCR、原位杂交和RNA干扰等方法,对罗氏沼虾Spo11基因(MrSpo11)及其编码氨基酸的分子特征、MrSpo11基因的组织表达、分布和生物学功能进行了研究。结果表明:MrSpo11基因cDNA序列全长为2298 bp,其中,5′端和3′端非编码区分别为457、701 bp,开放阅读框为1140 bp,共编码379个氨基酸残基;MrSpo11基因在罗氏沼虾鳃中的相对表达量最高,在卵巢、肝胰腺和心脏中表达量较高,在脑、眼和肌肉中微量表达;MrSpo11基因在罗氏沼虾卵巢发育Ⅰ期相对表达量最高,在卵巢发育Ⅲ期次之,在Ⅱ期和Ⅳ期表达量最低;MrSpo11基因在卵黄发生前期、中期、晚期卵母细胞的细胞质,以及卵黄发生早期卵母细胞的细胞质和细胞核中均有表达;注射dsRNA后第2、4天,试验组MrSpo11基因的表达量分别比对照组下降45.8%、11.6%,注射dsRNA后第4天,试验组卵巢发育成熟度略低于对照组。研究表明,MrSpo11基因参与了罗氏沼虾卵巢发育过程,本研究结果可为进一步探究罗氏沼虾卵巢发育分子调控机制提供有益参考。展开更多
Meiotic prophase I is a long and complex phase. Homologous recombination is an important process that occurs between homologous chromosomes during meiotic prophase I. Formation of chiasmata, which hold homologous chro...Meiotic prophase I is a long and complex phase. Homologous recombination is an important process that occurs between homologous chromosomes during meiotic prophase I. Formation of chiasmata, which hold homologous chromosomes together until the metaphase I to anaphase I transition, is critical for proper chromosome segregation. Recent studies have suggested that the SPO 11 proteins have conserved functions in a number of organisms in generating sites of double-stranded DNA breaks （DSBs） that are thought to be the starting points of homologous recombination. Processing of these sites of DSBs requires the function of RecA homologs, such as RAD5 1, DMC 1, and others, as suggested by mutant studies; thus the failure to repair these meiotic DSBs results in abnormal chromosomal alternations, leading to disrupted meiosis. Recent discoveries on the functions of these RecA homologs have improved the understanding of the mechanisms underlying meiotic homologous recombination.展开更多
Spermatogenesis is a highly complex developmental process that typically consists of mitosis, meiosis, and spermiogenesis. DNA/RNA helicase DHX36, a unique guanine-quadruplex (G4) resolvase, plays crucial roles in a v...Spermatogenesis is a highly complex developmental process that typically consists of mitosis, meiosis, and spermiogenesis. DNA/RNA helicase DHX36, a unique guanine-quadruplex (G4) resolvase, plays crucial roles in a variety of biological processes. We previously showed that DHX36 is highly expressed in male germ cells with the highest level in zygotene spermatocytes. Here, we deleted Dhx36 in advanced germ cells with Stra8-GFPCre and found that a Dhx36 deficiency in the differentiated spermatogonia leads to meiotic defects and abnormal spermiogenesis. These defects in late stages of spermatogenesis arise from dysregulated transcription of G4-harboring genes, which are required for meiosis. Thus, this study reveals that Dhx36 plays crucial roles in late stages of spermatogenesis.展开更多
基金The authors thank Alexandra Surcel and Carey L Hendrix Lord for helpful comments on this manuscript.The work in our laboratory is supported by grants from the National Science Foundation(IBN-0077832,MCB-9896340,MCB-0092075)the National Institutes of Health(R0 1 GM63871)+3 种基金the US Department of Agriculture(2001-35301-10570 and 2003-35301-13313)Wuxing L was partially supported by the Intercollege Graduate Degree Program in Plant PhysiologyHong M gratefully acknowledges the support of the John Simon Guggenheim Foundationthe National Institutes of Health(F33 GM72245-1).
文摘Meiotic prophase I is a long and complex phase. Homologous recombination is an important process that occurs between homologous chromosomes during meiotic prophase I. Formation of chiasmata, which hold homologous chromosomes together until the metaphase I to anaphase I transition, is critical for proper chromosome segregation. Recent studies have suggested that the SPO 11 proteins have conserved functions in a number of organisms in generating sites of double-stranded DNA breaks （DSBs） that are thought to be the starting points of homologous recombination. Processing of these sites of DSBs requires the function of RecA homologs, such as RAD5 1, DMC 1, and others, as suggested by mutant studies; thus the failure to repair these meiotic DSBs results in abnormal chromosomal alternations, leading to disrupted meiosis. Recent discoveries on the functions of these RecA homologs have improved the understanding of the mechanisms underlying meiotic homologous recombination.
基金supported by grants from the National Key R&D Program of China(2021YFC2700200 and 2022YFC2702602)the National Natural Science Foundation of China(31930034)the Science and Technology Commission of Shanghai Municipality(19JC1415800 to M.-H.T.).
文摘Spermatogenesis is a highly complex developmental process that typically consists of mitosis, meiosis, and spermiogenesis. DNA/RNA helicase DHX36, a unique guanine-quadruplex (G4) resolvase, plays crucial roles in a variety of biological processes. We previously showed that DHX36 is highly expressed in male germ cells with the highest level in zygotene spermatocytes. Here, we deleted Dhx36 in advanced germ cells with Stra8-GFPCre and found that a Dhx36 deficiency in the differentiated spermatogonia leads to meiotic defects and abnormal spermiogenesis. These defects in late stages of spermatogenesis arise from dysregulated transcription of G4-harboring genes, which are required for meiosis. Thus, this study reveals that Dhx36 plays crucial roles in late stages of spermatogenesis.
