As lower vertebrates, fishes have complex modes of sex determination. From the cytogenetic perspective, only a small proportion of fish species have heteromorphic sex chromosomes. At the present stage sex determinatio...As lower vertebrates, fishes have complex modes of sex determination. From the cytogenetic perspective, only a small proportion of fish species have heteromorphic sex chromosomes. At the present stage sex determination can only be explained via "genetics" rather than "genes" in most species. Nevertheless, genes associated with sex determination and male development were identified in a model fish medaka, Oryzias latipes. Sequences or genetic markers specific to certain sex chromosomes were reported in some fishes. These findings lay the groundwork for further studies on the function and regulation of sex genes aiming at elucidation of the mechanism of sex determination, and provide potential tool for sexing fish. In this minireview, progress in the past few decades in both cytogenetic and molecular genetic studies on sex determination of fish were summarized. Prospects, significance and possible future directions of the studies on fish sex determination were also discussed.展开更多
Sex is prevalent in nature and sex determination is one of the most fundamental biological processes, while the way of initiating female and male development exhibits remarkable diversity and variability across verteb...Sex is prevalent in nature and sex determination is one of the most fundamental biological processes, while the way of initiating female and male development exhibits remarkable diversity and variability across vertebrates. The knowledge on why and how sex determination mechanisms evolve unusual plasticity remains limited. Here, we summarize sex determination systems,master sex-determining genes and gene-regulatory networks among vertebrates. Recent research advancements on sex determination system transition are also introduced and discussed in some non-model animals with multiple sex determination mechanisms. This review will provide insights into the origin, transition and evolutionary adaption of different sex determination strategies in vertebrates, as well as clues for future perspectives in this field.展开更多
Sex determination in plants gives rise to unisexual flowers that facilitate outcrossing and enhance genetic diversity. In cucumber and melon, ethylene promotes carpel development and arrests sta- men development. Five...Sex determination in plants gives rise to unisexual flowers that facilitate outcrossing and enhance genetic diversity. In cucumber and melon, ethylene promotes carpel development and arrests sta- men development. Five sex-determination genes have been identified, including four encoding 1-aminocyclopropane-l-carboxylate （ACC） synthase that catalyzes the rate-limiting step in ethylene biosynthesis, and a transcription factor gene CmWIP1 that corresponds to the Mendelian locus gynoecious in melon and is a negative regulator of femaleness. ACC oxidase （ACO） converts ACC into ethylene; how- ever, it remains elusive which ACO gene in the cucumber genome is critical for sex determination and how CmWIP1 represses development of female flowers. In this study, we discovered that mutation in an ACO gene, CsAC02, confers androecy in cucumber that bears only male flowers. The mutation disrupts the enzymatic activity of CsAC02, resulting in 50% less ethylene emission from shoot tips. CsAC02 was ex- pressed in the carpel primordia and its expression overlapped with that of CsACS11 in female flowers at key stages for sex determination, presumably providing sufficient ethylene required for proper CsACS2 expression. CmAC03, the ortholog of CsACO2, showed a similar expression pattern in the carpel region, suggesting a conserved function of CsACO2/CmACO3. We demonstrated that CsWlP1, the ortholog of CmWlP1, could directly bind the promoter of CsAC02 and repress its expression. Taken together, we propose a presumably conserved regulatory module consisting of WlP1 transcription factor and ACO controls unisexual flower development in cucumber and melon.展开更多
文摘As lower vertebrates, fishes have complex modes of sex determination. From the cytogenetic perspective, only a small proportion of fish species have heteromorphic sex chromosomes. At the present stage sex determination can only be explained via "genetics" rather than "genes" in most species. Nevertheless, genes associated with sex determination and male development were identified in a model fish medaka, Oryzias latipes. Sequences or genetic markers specific to certain sex chromosomes were reported in some fishes. These findings lay the groundwork for further studies on the function and regulation of sex genes aiming at elucidation of the mechanism of sex determination, and provide potential tool for sexing fish. In this minireview, progress in the past few decades in both cytogenetic and molecular genetic studies on sex determination of fish were summarized. Prospects, significance and possible future directions of the studies on fish sex determination were also discussed.
基金supported by the Key Program of Frontier Sciences of the Chinese Academy of Sciences (QYZDY-SSWSMC025)the National Natural Science Foundation of China (31502148 and 31873036)+3 种基金the Earmarked Fund for Modern Agro-industry Technology Research System (NYCYTX-49)the Autonomous Project of the State Key Laboratory of Freshwater Ecology and Biotechnology (2016FBZ01)the Autonomous Project of the Institute of Hydrobiology, Chinese Academy of Sciences (Y25A171)the Knowledge Innovation Program of the Chinese Academy of Science
文摘Sex is prevalent in nature and sex determination is one of the most fundamental biological processes, while the way of initiating female and male development exhibits remarkable diversity and variability across vertebrates. The knowledge on why and how sex determination mechanisms evolve unusual plasticity remains limited. Here, we summarize sex determination systems,master sex-determining genes and gene-regulatory networks among vertebrates. Recent research advancements on sex determination system transition are also introduced and discussed in some non-model animals with multiple sex determination mechanisms. This review will provide insights into the origin, transition and evolutionary adaption of different sex determination strategies in vertebrates, as well as clues for future perspectives in this field.
文摘Sex determination in plants gives rise to unisexual flowers that facilitate outcrossing and enhance genetic diversity. In cucumber and melon, ethylene promotes carpel development and arrests sta- men development. Five sex-determination genes have been identified, including four encoding 1-aminocyclopropane-l-carboxylate （ACC） synthase that catalyzes the rate-limiting step in ethylene biosynthesis, and a transcription factor gene CmWIP1 that corresponds to the Mendelian locus gynoecious in melon and is a negative regulator of femaleness. ACC oxidase （ACO） converts ACC into ethylene; how- ever, it remains elusive which ACO gene in the cucumber genome is critical for sex determination and how CmWIP1 represses development of female flowers. In this study, we discovered that mutation in an ACO gene, CsAC02, confers androecy in cucumber that bears only male flowers. The mutation disrupts the enzymatic activity of CsAC02, resulting in 50% less ethylene emission from shoot tips. CsAC02 was ex- pressed in the carpel primordia and its expression overlapped with that of CsACS11 in female flowers at key stages for sex determination, presumably providing sufficient ethylene required for proper CsACS2 expression. CmAC03, the ortholog of CsACO2, showed a similar expression pattern in the carpel region, suggesting a conserved function of CsACO2/CmACO3. We demonstrated that CsWlP1, the ortholog of CmWlP1, could directly bind the promoter of CsAC02 and repress its expression. Taken together, we propose a presumably conserved regulatory module consisting of WlP1 transcription factor and ACO controls unisexual flower development in cucumber and melon.
