Vitellogenesis is the main event of oocyte growth in oviparous animals,which is mainly manifested by the accumulation of vitellogenin(VTG).The accumulation of vitellogenin depends mainly on the absorption of exogenous...Vitellogenesis is the main event of oocyte growth in oviparous animals,which is mainly manifested by the accumulation of vitellogenin(VTG).The accumulation of vitellogenin depends mainly on the absorption of exogenous vitellogenin,which enters oocyte through endocytosis mediated by its receptor(VGR).We investigated the expression and localization of VTG and VGR during gonad development of Pampus argenteus.The qPCR results show that vtgs were not expressed in male fish,but in the ovary and liver of female fish;the expression levels went up at first and then down.The expression levels of vgr in the testis were low and only 1%-3%of that in ovary.ELISA results show that during the ovarian development of P.argenteus,VTG in liver,serum,and ovary all showed a trend from increasing to decreasing.However,VTG in liver peaked in StageⅣ,and in serum and ovary peaked in Stage V,reflecting changes in the characteristics of VTG in the liver(synthesis),blood(transport),and ovaries(accumulation).During gonad development,VGR in the ovaries first increased and then decreased,reaching a peak in Stage V,in contrast to vgr mRNA expression.The VGR content in the testis was extremely low and stable,consistent with vgr mRNA.Immunohistochemistry results show that the location and intensity of VTG and VGR positive signals were synchronized with the changes of their protein content,which revealed that VTG was mainly synthesized in the liver cytoplasm,secreted into the blood,and transported to ovary in StageⅢ.VGR is highly expressed in oocytes in StageⅡ.In StageⅢ,a large amount of VTG reaches the ovary,when VGR begins to translate and is subsequently transported to the plasma membrane of the oocyte.Therefore,the positive signal of VGR was stronger near the plasma membrane of oocytes in StagesⅠandⅡ.By using qPCR,ELISA,and immunohistochemistry,the synthesis,transport,and accumulation of vitellogenin were elucidated and the mechanism of its endocytosis on egg membrane mediated by VTG during the development of P.argenteus was reveale展开更多
1,2,3,7,8-PeCDD was administrated to juvenile goldfish （Carassius auratus） by peritoneal injections to explore the acute lethality and endocrine effects of 1,2,3,7,8-PeCDD in vivo. The value of acute median lethal d...1,2,3,7,8-PeCDD was administrated to juvenile goldfish （Carassius auratus） by peritoneal injections to explore the acute lethality and endocrine effects of 1,2,3,7,8-PeCDD in vivo. The value of acute median lethal dosage （LD50） of 1,2,3,7,8-PeCDD was determined in acute lethality tests. The endocrine effect of 1,2,3,7,8-PeCDD, whose exposed concentrations were determined based on the LD50 （1.84 mg/kg）, was studied by measuring the plasma vitellogenin （Vtg） content in juvenile male goldfish with enzyme-linked immunosorbent assays （ELISA）. Due to its significant induction of the plasma Vtg after one week＇s exposure in vivo in the 1/2 LD50 and LD30 groups, 1,2,3,7,8-PeCDD might be one of the important contributors to the estrogenic effect of PCDDs in the environment. The values of 1/2 LD50 and LD30 were within the range of the effective dosages of 1,2,3,7,8-PeCDD, indicating that there was a certain relationship between the estrogenic effective dosages and the LD50.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.31872586,42076118)the Major Project of Science,Technology and Innovation 2025 in Ningbo City(No.2021Z003)the K.C.Wong Magna Fund in Ningbo University。
文摘Vitellogenesis is the main event of oocyte growth in oviparous animals,which is mainly manifested by the accumulation of vitellogenin(VTG).The accumulation of vitellogenin depends mainly on the absorption of exogenous vitellogenin,which enters oocyte through endocytosis mediated by its receptor(VGR).We investigated the expression and localization of VTG and VGR during gonad development of Pampus argenteus.The qPCR results show that vtgs were not expressed in male fish,but in the ovary and liver of female fish;the expression levels went up at first and then down.The expression levels of vgr in the testis were low and only 1%-3%of that in ovary.ELISA results show that during the ovarian development of P.argenteus,VTG in liver,serum,and ovary all showed a trend from increasing to decreasing.However,VTG in liver peaked in StageⅣ,and in serum and ovary peaked in Stage V,reflecting changes in the characteristics of VTG in the liver(synthesis),blood(transport),and ovaries(accumulation).During gonad development,VGR in the ovaries first increased and then decreased,reaching a peak in Stage V,in contrast to vgr mRNA expression.The VGR content in the testis was extremely low and stable,consistent with vgr mRNA.Immunohistochemistry results show that the location and intensity of VTG and VGR positive signals were synchronized with the changes of their protein content,which revealed that VTG was mainly synthesized in the liver cytoplasm,secreted into the blood,and transported to ovary in StageⅢ.VGR is highly expressed in oocytes in StageⅡ.In StageⅢ,a large amount of VTG reaches the ovary,when VGR begins to translate and is subsequently transported to the plasma membrane of the oocyte.Therefore,the positive signal of VGR was stronger near the plasma membrane of oocytes in StagesⅠandⅡ.By using qPCR,ELISA,and immunohistochemistry,the synthesis,transport,and accumulation of vitellogenin were elucidated and the mechanism of its endocytosis on egg membrane mediated by VTG during the development of P.argenteus was reveale
基金This work was supported by the National Natural Science Foundation of China （No. 40332023, 20621703）.
文摘1,2,3,7,8-PeCDD was administrated to juvenile goldfish （Carassius auratus） by peritoneal injections to explore the acute lethality and endocrine effects of 1,2,3,7,8-PeCDD in vivo. The value of acute median lethal dosage （LD50） of 1,2,3,7,8-PeCDD was determined in acute lethality tests. The endocrine effect of 1,2,3,7,8-PeCDD, whose exposed concentrations were determined based on the LD50 （1.84 mg/kg）, was studied by measuring the plasma vitellogenin （Vtg） content in juvenile male goldfish with enzyme-linked immunosorbent assays （ELISA）. Due to its significant induction of the plasma Vtg after one week＇s exposure in vivo in the 1/2 LD50 and LD30 groups, 1,2,3,7,8-PeCDD might be one of the important contributors to the estrogenic effect of PCDDs in the environment. The values of 1/2 LD50 and LD30 were within the range of the effective dosages of 1,2,3,7,8-PeCDD, indicating that there was a certain relationship between the estrogenic effective dosages and the LD50.
