Black rockfish(Sebastes schlegelii)has evolved viviparous reproduction mode.Different from the oviparous fishes,the spermatozoa of black rockfish are stored on the surface of ovarian follicle for over four months unti...Black rockfish(Sebastes schlegelii)has evolved viviparous reproduction mode.Different from the oviparous fishes,the spermatozoa of black rockfish are stored on the surface of ovarian follicle for over four months until the egg mature in ovary,while the adaptive evolution of fertilization-related genes remains to be studied.In the present study,based on the genome and transcriptome information of black rockfish,a total of 10 hyaluronidase genes were identified by phylogenetic and sequence analyses,including hyal1,hyal2,hyal3,hyal4,hyal6 and spam1a,spam1b,spam1c and spam1d.The spam1 subfamilies,including spam1a,spam1b,spam1c and spam1d,were significantly expanded compared to other species.The adaptive evolution of hyaluronidase was further investigated by selection pressure analysis of branch model and branch site model.The results showed that only spam1 subfamily was positively selected with a large number of positive selection sites,and the evolution rate was significantly higher thanthose of other teleosts.Two positively selected sites,LYS-171 and GLY-164,were located in the neutral hyaluronidase activity domain,which was pivotal for SPAM1 to participate in enzymatic hydrolysis of the extracellular hyaluronic acid matrix and mediate acrosome reaction in mammals.Furthermore,spam1 was mainly expressed in spermatocytes,secondary spermatocytes,and spermatids of testis,whereas it was not found in metamorphic sperm and mature sperm based on the spatiotemporal expression analysis.All results indicated that spam1 might originate from the testis and might be an adaptation of viviparous trait in black rockfish.展开更多
基于Web of Science和CNKI数据库,运用CiteSpace、VOSviewer等计量分析软件系统梳理过去43年间中外关于冬奥会的理论研究,客观呈现中外在冬奥学术舞台上的现实处境和话语地位,为新时代我国加强冬奥学术话语体系构建提供参考。研究发现:1...基于Web of Science和CNKI数据库,运用CiteSpace、VOSviewer等计量分析软件系统梳理过去43年间中外关于冬奥会的理论研究,客观呈现中外在冬奥学术舞台上的现实处境和话语地位,为新时代我国加强冬奥学术话语体系构建提供参考。研究发现:1)国外的冬奥学术成果融合了多学科的知识体系和思想内容、中国则是体育单一学科撑起了冬奥理论研究的半边天;2)以欧美为代表的西方国家之间、研究机构之间、研究团体之间等建立了网状结构的合作关系,中国的研究机构、团体等对外和对内合作的连线相较稀疏,跨机构、跨区域、跨领域的交流和协同尚不足;3)中国关于冬奥会的理论研究在路径上异于国外、在主题上同步国外、在影响力上低于国外;4)国外的冬奥研究轨迹和路径变化呈现出“由点及线到面”的特征,中国则呈现出“由远及近、由外及里”的演变特征,前者蹚出了一条内生式构建冬奥知识体系的路子,后者开拓出了一条由“域外借鉴”向“自主探索”方向前进的冬奥研究之路。对未来中国冬奥研究的建议:1)接续输出北京冬奥会上的“中国成果”;2)接续提升我国冬奥竞技实力的国际地位;3)接续探索冬奥理论成果传播的多元化方式。展开更多
基金supported by the National Natural Science Foundation of China(Nos.32273133,31970492).
文摘Black rockfish(Sebastes schlegelii)has evolved viviparous reproduction mode.Different from the oviparous fishes,the spermatozoa of black rockfish are stored on the surface of ovarian follicle for over four months until the egg mature in ovary,while the adaptive evolution of fertilization-related genes remains to be studied.In the present study,based on the genome and transcriptome information of black rockfish,a total of 10 hyaluronidase genes were identified by phylogenetic and sequence analyses,including hyal1,hyal2,hyal3,hyal4,hyal6 and spam1a,spam1b,spam1c and spam1d.The spam1 subfamilies,including spam1a,spam1b,spam1c and spam1d,were significantly expanded compared to other species.The adaptive evolution of hyaluronidase was further investigated by selection pressure analysis of branch model and branch site model.The results showed that only spam1 subfamily was positively selected with a large number of positive selection sites,and the evolution rate was significantly higher thanthose of other teleosts.Two positively selected sites,LYS-171 and GLY-164,were located in the neutral hyaluronidase activity domain,which was pivotal for SPAM1 to participate in enzymatic hydrolysis of the extracellular hyaluronic acid matrix and mediate acrosome reaction in mammals.Furthermore,spam1 was mainly expressed in spermatocytes,secondary spermatocytes,and spermatids of testis,whereas it was not found in metamorphic sperm and mature sperm based on the spatiotemporal expression analysis.All results indicated that spam1 might originate from the testis and might be an adaptation of viviparous trait in black rockfish.
文摘基于Web of Science和CNKI数据库,运用CiteSpace、VOSviewer等计量分析软件系统梳理过去43年间中外关于冬奥会的理论研究,客观呈现中外在冬奥学术舞台上的现实处境和话语地位,为新时代我国加强冬奥学术话语体系构建提供参考。研究发现:1)国外的冬奥学术成果融合了多学科的知识体系和思想内容、中国则是体育单一学科撑起了冬奥理论研究的半边天;2)以欧美为代表的西方国家之间、研究机构之间、研究团体之间等建立了网状结构的合作关系,中国的研究机构、团体等对外和对内合作的连线相较稀疏,跨机构、跨区域、跨领域的交流和协同尚不足;3)中国关于冬奥会的理论研究在路径上异于国外、在主题上同步国外、在影响力上低于国外;4)国外的冬奥研究轨迹和路径变化呈现出“由点及线到面”的特征,中国则呈现出“由远及近、由外及里”的演变特征,前者蹚出了一条内生式构建冬奥知识体系的路子,后者开拓出了一条由“域外借鉴”向“自主探索”方向前进的冬奥研究之路。对未来中国冬奥研究的建议:1)接续输出北京冬奥会上的“中国成果”;2)接续提升我国冬奥竞技实力的国际地位;3)接续探索冬奥理论成果传播的多元化方式。
