Vitellogenin receptor(VgR)is crucial for vitellogenin(Vg)uptake by oocytes.VgR is less known in Arachnida,especially in spiders.Different from only one VgR in an arthropod species,two VgRs,VgR-1 and VgR-2,were found i...Vitellogenin receptor(VgR)is crucial for vitellogenin(Vg)uptake by oocytes.VgR is less known in Arachnida,especially in spiders.Different from only one VgR in an arthropod species,two VgRs,VgR-1 and VgR-2,were found in the pond wolf spider,Pardosa pseudoannulata.Both VgRs had the typical domains of the low-density lipoprotein receptor family except for the absence of the ligand-binding domain 1 in VgR-2.Spatiotemporal expression profiles showed that two VgR genes were consistently highly expressed in females and their ovaries,but VgR-1 was 48-fold that of VgR-2 in ovaries.The transcriptional level of VgR-1 was significantly downregulated by RNAi,but it did not work for VgR-2 although several trials were performed.Vg-1 and Vg-2 might be the ligands of VgR-1 because their expressions were also decreased in the dsVgR-1-treated females.Silencing VgR-1 prolonged the pre-oviposition period by 56 h.The expression of VgRs and Vgs were upregulated by juvenile hormones(JHs),which suggested that JHs were the essential factors to vitellogenesis in the spider.The present study revealed the importance of VgR-1 in the spider oviposition,which will improve the understanding on VgR physiological functions in spiders.展开更多
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
基金supported by the Fundamental Research Funds for the Central Universities(grant number:KJQN201809)the National Natural Science Foundation(grant number:31772185,31972296).
文摘Vitellogenin receptor(VgR)is crucial for vitellogenin(Vg)uptake by oocytes.VgR is less known in Arachnida,especially in spiders.Different from only one VgR in an arthropod species,two VgRs,VgR-1 and VgR-2,were found in the pond wolf spider,Pardosa pseudoannulata.Both VgRs had the typical domains of the low-density lipoprotein receptor family except for the absence of the ligand-binding domain 1 in VgR-2.Spatiotemporal expression profiles showed that two VgR genes were consistently highly expressed in females and their ovaries,but VgR-1 was 48-fold that of VgR-2 in ovaries.The transcriptional level of VgR-1 was significantly downregulated by RNAi,but it did not work for VgR-2 although several trials were performed.Vg-1 and Vg-2 might be the ligands of VgR-1 because their expressions were also decreased in the dsVgR-1-treated females.Silencing VgR-1 prolonged the pre-oviposition period by 56 h.The expression of VgRs and Vgs were upregulated by juvenile hormones(JHs),which suggested that JHs were the essential factors to vitellogenesis in the spider.The present study revealed the importance of VgR-1 in the spider oviposition,which will improve the understanding on VgR physiological functions in spiders.
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.
文摘从成熟的克氏原螯虾卵巢中提取总RNA,通过同源克隆得到了卵黄蛋白原受体c DNA部分序列,长度为506 bp,在NCBI网站上进行比对后发现,其与斑节对虾、短沟对虾、罗氏沼虾的卵黄蛋白原受体(Vg R)c DNA序列有较高的相似性。采用实时荧光定量PCR方法,测定了卵巢不同发育时期卵巢和肝胰腺两个组织中卵黄蛋白原受体m RNA的相对表达水平。结果显示,卵巢是卵黄蛋白原受体基因表达的主要部位,而肝胰腺只能检测到少量表达,卵黄蛋白原受体基因在卵巢的卵原细胞增殖期相对表达量最高,随后下降,成熟期达到最低值,恢复期开始回升。结合卵巢不同发育阶段卵巢质量的变化计算表达总量,结果发现,卵黄蛋白原受体基因的表达总量在卵原细胞增殖期为最低,随后持续升高并至成熟期达到峰值,恢复期急剧下降,但仍略高于卵原细胞增殖期的表达量。此外,运用所构建的系统进化树比较了克氏原螯虾Vg R m RNA与其他物种间的遗传距离。
