The small yellow croaker Larimichthys polyactis is an economically important marine fish in Northeast Asia.Currently,its natural resources are threatened by overfishing and environmental pollution.Therefore,research o...The small yellow croaker Larimichthys polyactis is an economically important marine fish in Northeast Asia.Currently,its natural resources are threatened by overfishing and environmental pollution.Therefore,research on the reproductive system of the fish is crucial.Here,we studied the testis development and ultrastructural features of spermatogenesis in cultured L.polyactis using anatomical,histological,and ultrastructural techniques.A pair of testes,consisting of a central sperm duct and radial seminiferous lobules,were observed.The reproduction cycle of testes can be divided into stages I–VI.March to May was confirmed as the breeding season for male L.polyactis,while April is the ideal period for artificial breeding.The male L.polyactis can attain sexual maturity within 1 year.The spermatogenesis of L.polyactis comprised spermatogonium,spermatocyte,spermatid,and mature spermatozoon.The morphology of spermatogenic cells changed obviously during spermiogenesis,including nuclear shaping,midpiece and flagellum formation.The mature sperms consist of an ellipsoidal head,a short midpiece,and a long flagellum.The anterior of the head with a kidney-shaped nucleus can be distinguished.The midpiece is located posterior to the head and includes four to six spherical mitochondria.The flagellum has irregular lateral fins.The testis of L.polyactis is an unrestricted lobular type,with cystic spermatogenesis,type II spermiogenesis,and type II spermatozoa.These features are highly similar to those of other Sciaenid species.Our findings provide useful insights into the mechanism underlying testis development and spermatogenesis of L.polyactis,which can facilitate the artificial breeding of this species.展开更多
KIF3A and KIF3B are two N-terminal motor proteins belonging to the kinesin-II superfamily that play essential roles in spermiogenesis.To understand the roles played by KIF3 A/3B during spermatogenesis of large yellow ...KIF3A and KIF3B are two N-terminal motor proteins belonging to the kinesin-II superfamily that play essential roles in spermiogenesis.To understand the roles played by KIF3 A/3B during spermatogenesis of large yellow croaker Larimichthys crocea,we studied the testis characteristics at different developmental stages of L.crocea,and determined the spatiotemporal expression patterns of kif3a and kif3b during spermiogenesis.Quantitative real-time PCR(qR T-PCR)showed that the overall trends of kif3 a/3 b m RNA abundance during testis development are similar.From stage Ⅱ to stage V,kif3a/3b m RNA abundances first increased and then fell after reaching a peak at stage IV.Interestingly,the m RNA abundances of both genes at stage V were higher than those at stages Ⅱ and Ⅲ.In addition,it is worth of noting that kif3 b m RNA abundance was higher than that of kif3a at all stages.Fluorescence in situ hybridization results revealed that kif3a/3b m RNA abundance dynamics were consistent with the migration of mitochondria,the deformation of nucleus,and the formation of tail.The m RNA hybridization signals of both genes first appeared either around the nuclear periphery or on the side of the nuclei,then appeared at one side of nuclei,and finally were mainly on the tail during spermiogenesis.Our findings contributed to better understanding the molecular mechanisms of spermiogenesis in fish;and suggested that KIF3A and KIF3B may participate in the intracellular transport of mitochondria,nuclear deformation,and the formation of tail during the spermiogenesis in L.crocea.展开更多
基金the NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization(No.U1809212)the Scientific and Technical Project of Zhejiang Province(Nos.2021C02055,2017C02013)+2 种基金the National Natural Science Foundation of China(No.31272642)Healthy Aquaculture,the K.C.Wong Magna Fund in Ningbo Universitythe Collaborative Innovation Center for Zhejiang Marine High-Efficiency。
文摘The small yellow croaker Larimichthys polyactis is an economically important marine fish in Northeast Asia.Currently,its natural resources are threatened by overfishing and environmental pollution.Therefore,research on the reproductive system of the fish is crucial.Here,we studied the testis development and ultrastructural features of spermatogenesis in cultured L.polyactis using anatomical,histological,and ultrastructural techniques.A pair of testes,consisting of a central sperm duct and radial seminiferous lobules,were observed.The reproduction cycle of testes can be divided into stages I–VI.March to May was confirmed as the breeding season for male L.polyactis,while April is the ideal period for artificial breeding.The male L.polyactis can attain sexual maturity within 1 year.The spermatogenesis of L.polyactis comprised spermatogonium,spermatocyte,spermatid,and mature spermatozoon.The morphology of spermatogenic cells changed obviously during spermiogenesis,including nuclear shaping,midpiece and flagellum formation.The mature sperms consist of an ellipsoidal head,a short midpiece,and a long flagellum.The anterior of the head with a kidney-shaped nucleus can be distinguished.The midpiece is located posterior to the head and includes four to six spherical mitochondria.The flagellum has irregular lateral fins.The testis of L.polyactis is an unrestricted lobular type,with cystic spermatogenesis,type II spermiogenesis,and type II spermatozoa.These features are highly similar to those of other Sciaenid species.Our findings provide useful insights into the mechanism underlying testis development and spermatogenesis of L.polyactis,which can facilitate the artificial breeding of this species.
基金financially supported by the Scientific and Technical Project of Zhejiang Province (Nos. 2016C02055-7, LY18C190007)the Ningbo Natural Science Foundation (No. 2016A610081)+3 种基金the Scientific and Technical Project of Ningbo (No. 2015C110005)the National Natural Science Foundation of China (No. 31602140)the Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculturethe K. C. Wong Magna Fund in Ningbo University
文摘KIF3A and KIF3B are two N-terminal motor proteins belonging to the kinesin-II superfamily that play essential roles in spermiogenesis.To understand the roles played by KIF3 A/3B during spermatogenesis of large yellow croaker Larimichthys crocea,we studied the testis characteristics at different developmental stages of L.crocea,and determined the spatiotemporal expression patterns of kif3a and kif3b during spermiogenesis.Quantitative real-time PCR(qR T-PCR)showed that the overall trends of kif3 a/3 b m RNA abundance during testis development are similar.From stage Ⅱ to stage V,kif3a/3b m RNA abundances first increased and then fell after reaching a peak at stage IV.Interestingly,the m RNA abundances of both genes at stage V were higher than those at stages Ⅱ and Ⅲ.In addition,it is worth of noting that kif3 b m RNA abundance was higher than that of kif3a at all stages.Fluorescence in situ hybridization results revealed that kif3a/3b m RNA abundance dynamics were consistent with the migration of mitochondria,the deformation of nucleus,and the formation of tail.The m RNA hybridization signals of both genes first appeared either around the nuclear periphery or on the side of the nuclei,then appeared at one side of nuclei,and finally were mainly on the tail during spermiogenesis.Our findings contributed to better understanding the molecular mechanisms of spermiogenesis in fish;and suggested that KIF3A and KIF3B may participate in the intracellular transport of mitochondria,nuclear deformation,and the formation of tail during the spermiogenesis in L.crocea.
