Zebrafish serve as a valuable model organism for studying germ cell biology and reproductive processes.The AB strain of zebrafish is proposed to exhibit a polygenic sex determination system,where most males initially ...Zebrafish serve as a valuable model organism for studying germ cell biology and reproductive processes.The AB strain of zebrafish is proposed to exhibit a polygenic sex determination system,where most males initially develop juvenile ovaries before committing to male fate.In species with chromosomal sex determination,gonadal somatic cells are recognized as key determinants of germ cell fate.Notably,the loss of germ cells in zebrafish leads to masculinization,implying that germ cells harbor an intrinsic feminization signal.However,the specific signal triggering oogenesis in zebrafish remains unclear.In the present study,we identified foxl2l as an oocyte progenitor-specific gene essential for initiating oogenesis in germ cells.Results showed that foxl2l-knockout zebrafish bypassed the juvenile ovary stage and exclusively developed into fertile males.Further analysis revealed that loss of foxl2l hindered the initiation of oocyte-specific meiosis and prevented entry into oogenesis,leading to premature spermatogenesis during early gonadal development.Furthermore,while mutation of the pro-male gene dmrt1 led to fertile female differentiation,simultaneous disruption of foxl2l in dmrt1 mutants completely blocked oogenesis,with a large proportion of germ cells arrested as germline stem cells,highlighting the crucial role of foxl2l in oogenesis.Overall,this study highlights the unique function of foxl2l as a germ cell-intrinsic gatekeeper of oogenesis in zebrafish.展开更多
Locations around the equator provide unique habitats for microalgae presumably with exceptional vitality.To develop microalga-derived product systems,we previously created a(sub)tropical microalgal collection.In this ...Locations around the equator provide unique habitats for microalgae presumably with exceptional vitality.To develop microalga-derived product systems,we previously created a(sub)tropical microalgal collection.In this study,two Chlorella strains(MEM176 and MEM193),adaptive to typical tropical climate,were isolated from the collection.The production performance was evaluated where both strains showed a robust growth in high temperatures and light intensities.Specifically,the strains MEM176 and MEM193 produced 503.6-mg/(L·d)and 411.3-mg/(L·d)biomass,respectively,with high contents of proteins.Their commercial and nutritional values were emphasized by amino acid compositions(e.g.,proline,valine,and phenylalanine).Particularly,higher amounts of proline were revealed in MEM176(47.9 mg/g dry biomass(DW))and MEM193(47.9 and 59.2 mg/g DW)than available commercial strains.Compared with MEM193,MEM176 produced 129.7%more lipids in which unsaturated fatty acids(particularly linoleic acid andα-linolenic acid)account for 65%of the total lipids.Therefore,it is promising to explore the potential of these Chlorella strains as food additives via outdoor cultivation in tropical area,notably MEM176 that exhibits superiority as sources of essential amino acids and valuable fatty acids.展开更多
基金supported by the National Natural Science Foundation of China(32025037)Ministry of Science and Technology of China(2023YFD2401603)+2 种基金Ministry of Agriculture and Rural Affairs of China(NK2022010207)Science and Technology Special Fund of Hainan Province(ZDYF2024XDNY256)Natural Science Foundation of Wuhan。
文摘Zebrafish serve as a valuable model organism for studying germ cell biology and reproductive processes.The AB strain of zebrafish is proposed to exhibit a polygenic sex determination system,where most males initially develop juvenile ovaries before committing to male fate.In species with chromosomal sex determination,gonadal somatic cells are recognized as key determinants of germ cell fate.Notably,the loss of germ cells in zebrafish leads to masculinization,implying that germ cells harbor an intrinsic feminization signal.However,the specific signal triggering oogenesis in zebrafish remains unclear.In the present study,we identified foxl2l as an oocyte progenitor-specific gene essential for initiating oogenesis in germ cells.Results showed that foxl2l-knockout zebrafish bypassed the juvenile ovary stage and exclusively developed into fertile males.Further analysis revealed that loss of foxl2l hindered the initiation of oocyte-specific meiosis and prevented entry into oogenesis,leading to premature spermatogenesis during early gonadal development.Furthermore,while mutation of the pro-male gene dmrt1 led to fertile female differentiation,simultaneous disruption of foxl2l in dmrt1 mutants completely blocked oogenesis,with a large proportion of germ cells arrested as germline stem cells,highlighting the crucial role of foxl2l in oogenesis.Overall,this study highlights the unique function of foxl2l as a germ cell-intrinsic gatekeeper of oogenesis in zebrafish.
基金Supported by the National Key R&D Program of China(Nos.2021YFA0909600,2021YFE0110100)the National Natural Science Foundation of China(Nos.32060061,32370380)+3 种基金the Key R&D Program of Hainan Province(Nos.ZDYF2024XDNY244,ZDYF2022XDNY140)the Natural Science Foundation of Hainan Province(No.322QN250)the Foreign Expert Foundation of Hainan Province(No.G20230607016E)the Program of Key Lab of Ministry of Education for Utilization and Conservation of Tropical Marine Bioresources(No.2023SCNFKF04)。
文摘Locations around the equator provide unique habitats for microalgae presumably with exceptional vitality.To develop microalga-derived product systems,we previously created a(sub)tropical microalgal collection.In this study,two Chlorella strains(MEM176 and MEM193),adaptive to typical tropical climate,were isolated from the collection.The production performance was evaluated where both strains showed a robust growth in high temperatures and light intensities.Specifically,the strains MEM176 and MEM193 produced 503.6-mg/(L·d)and 411.3-mg/(L·d)biomass,respectively,with high contents of proteins.Their commercial and nutritional values were emphasized by amino acid compositions(e.g.,proline,valine,and phenylalanine).Particularly,higher amounts of proline were revealed in MEM176(47.9 mg/g dry biomass(DW))and MEM193(47.9 and 59.2 mg/g DW)than available commercial strains.Compared with MEM193,MEM176 produced 129.7%more lipids in which unsaturated fatty acids(particularly linoleic acid andα-linolenic acid)account for 65%of the total lipids.Therefore,it is promising to explore the potential of these Chlorella strains as food additives via outdoor cultivation in tropical area,notably MEM176 that exhibits superiority as sources of essential amino acids and valuable fatty acids.
