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
The contamination of fish type products such as silver pomfret fish fillets by potentially toxic elements(PTEs)has raised global health concerns.Related studies regarding the concentration of PTEs in fillets of silver...The contamination of fish type products such as silver pomfret fish fillets by potentially toxic elements(PTEs)has raised global health concerns.Related studies regarding the concentration of PTEs in fillets of silver pomfret fish were retrieved among some international databases such as Scopus,Pub Med and Embase between 1 January 1983 and 10 March 2020.The pooled(mean)concentration of PTEs in fillets of silver pomfret fish was meta-analyzed with the aid of a random-effect model(REM).Also,the non-carcinogenic risk was estimated via calculating the 95 th percentile of the total target hazard quotient(TTHQ).The meta-analysis of 21 articles(containing 25 studies or data reports)indicated that the ranking of PTEs in fillets of silver pomfret fish was Fe(11,414.81μg/kg wet weight,ww)>Zn(6055.72μg/kg ww)>Cr(1825.79μg/kg ww)>Pb(1486.44μg/kg ww)>Se(1053.47μg/kg ww)>Cd(992.50μg/kg ww)>Ni(745.23μg/kg ww)>Cu(669.71μg/kg ww)>total As(408.24μg/kg ww)>Co(87.03μg/kg ww)>methyl Hg(46.58μg/kg ww).The rank order of health risk assessment by country based on the TTHQ for adult consumers was Malaysia(2.500)>Bangladesh(0.886)>Iran(0.144)>China(0.045)>Pakistan(0.020)>India(0.015),while the corresponding values for child consumers was Malaysia(11.790)>Bangladesh(4.146)>Iran(0.675)>China(0.206)>Pakistan(0.096)>India(0.077).The adult consumers in Malaysia and children in Malaysia and Bangladesh were at considerable non-carcinogenic risk.Therefore,following the recommended control plans in order to reduce the health risk associated with the ingestion of PTEs via consumption of silver pomfret fish fillets is crucial.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the student research committee at Shahid Beheshti University of Medical Sciences for the financial grants supporting this study(1398/9920)。
文摘The contamination of fish type products such as silver pomfret fish fillets by potentially toxic elements(PTEs)has raised global health concerns.Related studies regarding the concentration of PTEs in fillets of silver pomfret fish were retrieved among some international databases such as Scopus,Pub Med and Embase between 1 January 1983 and 10 March 2020.The pooled(mean)concentration of PTEs in fillets of silver pomfret fish was meta-analyzed with the aid of a random-effect model(REM).Also,the non-carcinogenic risk was estimated via calculating the 95 th percentile of the total target hazard quotient(TTHQ).The meta-analysis of 21 articles(containing 25 studies or data reports)indicated that the ranking of PTEs in fillets of silver pomfret fish was Fe(11,414.81μg/kg wet weight,ww)>Zn(6055.72μg/kg ww)>Cr(1825.79μg/kg ww)>Pb(1486.44μg/kg ww)>Se(1053.47μg/kg ww)>Cd(992.50μg/kg ww)>Ni(745.23μg/kg ww)>Cu(669.71μg/kg ww)>total As(408.24μg/kg ww)>Co(87.03μg/kg ww)>methyl Hg(46.58μg/kg ww).The rank order of health risk assessment by country based on the TTHQ for adult consumers was Malaysia(2.500)>Bangladesh(0.886)>Iran(0.144)>China(0.045)>Pakistan(0.020)>India(0.015),while the corresponding values for child consumers was Malaysia(11.790)>Bangladesh(4.146)>Iran(0.675)>China(0.206)>Pakistan(0.096)>India(0.077).The adult consumers in Malaysia and children in Malaysia and Bangladesh were at considerable non-carcinogenic risk.Therefore,following the recommended control plans in order to reduce the health risk associated with the ingestion of PTEs via consumption of silver pomfret fish fillets is crucial.
