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 revealed preliminarily.展开更多
In order to investigate the endocrine toxicity of B(a)p to marine polychaete P erinereis aibuhitensis, vitellogenin(VTG) cDNA from the P. aibuhitensis was isolated, recombinated and expressed for the first time. The f...In order to investigate the endocrine toxicity of B(a)p to marine polychaete P erinereis aibuhitensis, vitellogenin(VTG) cDNA from the P. aibuhitensis was isolated, recombinated and expressed for the first time. The full length P. aibuhitensis vitellogenin gene(PaVTG) was 5 325 bp, and encoded 1 692 amino acids. It contained the vitellogenin_N domain of unknown function(DUF1943), a von Willebrand factor type D domain, as well as a conserved KALGNAG motif. The expression of VTG gene and protein were mainly up-regulated after exposed to B(a)p at transcriptional and translational levels. PaVTG gene expression did not change significantly at day 4. At day 7 PaVTG expression was up-regulated in 0.5 μg/L and 5 μg/L B(a)p group. At day 14 PaVTG was significantly up-regulated in 0.5–10 μg/L B(a)p. The protein expression of PaVTG in 0.5 μg/L and 10 μg/L B(a)p group was up-regulated with time prolonging, but the expression in 5 μg/L and 50 μg/L B(a)p group exhibited first increased and then decreased trend. With the increasing of B(a)p concentration PaVTG mRNA and protein expression both firstly increased then decreased. In contrast to B(a)p exposure, estradiol did not induce PaVTG gene and protein expression, until late times of exposure(14 d). Overall, the results in this study indicate that PaVTG could be used as a potential indicator of the effects environmental estrogenic compounds.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 revealed preliminarily.
基金Supported by the National Natural Science Foundation of China(No.41306138)the National Marine Public Welfare Research Project(Nos.201305002,201305043)the Foundation of Education Department of Liaoning Province(No.L201609)
文摘In order to investigate the endocrine toxicity of B(a)p to marine polychaete P erinereis aibuhitensis, vitellogenin(VTG) cDNA from the P. aibuhitensis was isolated, recombinated and expressed for the first time. The full length P. aibuhitensis vitellogenin gene(PaVTG) was 5 325 bp, and encoded 1 692 amino acids. It contained the vitellogenin_N domain of unknown function(DUF1943), a von Willebrand factor type D domain, as well as a conserved KALGNAG motif. The expression of VTG gene and protein were mainly up-regulated after exposed to B(a)p at transcriptional and translational levels. PaVTG gene expression did not change significantly at day 4. At day 7 PaVTG expression was up-regulated in 0.5 μg/L and 5 μg/L B(a)p group. At day 14 PaVTG was significantly up-regulated in 0.5–10 μg/L B(a)p. The protein expression of PaVTG in 0.5 μg/L and 10 μg/L B(a)p group was up-regulated with time prolonging, but the expression in 5 μg/L and 50 μg/L B(a)p group exhibited first increased and then decreased trend. With the increasing of B(a)p concentration PaVTG mRNA and protein expression both firstly increased then decreased. In contrast to B(a)p exposure, estradiol did not induce PaVTG gene and protein expression, until late times of exposure(14 d). Overall, the results in this study indicate that PaVTG could be used as a potential indicator of the effects environmental estrogenic compounds.
