饲养环境对中华绒螯蟹仔蟹生长与蜕壳相关基因表达的影响

中华绒螯蟹在不同饲养环境条件下生长存在巨大差异,为探讨不同环境条件对仔蟹生长和蜕壳相关基因表达的影响,了解基因表达的时空变化及其与环境的互作关系,本研究选取同一家系的大眼幼体和仔蟹分别饲养于室内玻璃钢水槽和室外小型水泥池两种环境,观察它们的生长差异,并应用荧光定量PCR(qRT-PCR)技术对甲壳动物高血糖素(CHH)、蜕皮抑制激素(MIH)、蜕皮激素受体(EcR)、维甲类X受体(RXR)以及性腺抑制激素(GIH)5个蜕壳相关基因的表达情况进行了分析。结果发现:室外水泥池饲养的仔蟹体质量均显著大于室内水槽饲养的仔蟹体质量(P0.05)。环境对MIH和RXR基因的表达不存在显著影响(P0.05),而CHH、EcR和GIH均存在极显著的环境表达差异(P0.01);5个基因(MIH、CHH、EcR、GIH和RXR)均存在显著的不同发育时期表达差异(P0.05);除MIH基因外,其他4个基因(RXR、CHH、EcR和GIH)的表达存在极显著的饲养环境与发育时期的交互作用(P0.01)。研究还发现,MIH、GIH和CHH对河蟹的蜕壳具有协同调控作用,而RXR与GIH对河蟹蜕壳具有一定程度的拮抗作用。

The effects of rearing environments on growth and expression of molting-related genes in larval Chinese mitten crabs

There is huge growth difference in Chinese mitten crab (Eriocheir sinensis) resulting from different culture environments. In order to study the influence of environment conditions on growth of larva crab, and to understand the temporal and spatial change of gene expression and their interaction with environments, the growth and gene expression characteristics were investigated for megalopas and larva crab employed from one family reared in outdoor ponds and indoor closet. Expression profiles of five molting-related genes using quantitative real-time PCR (RT-PCR) technology were investigated, including crustacean hyperglycemi hormone (CHH); molt-inhibiting hormone (MIH); ecdysteroid receptor (EcR); retinoid X receptor (RxR) and gonad-inhibiting hormone (GIH). The results indicated average weight of larva crabs reared in outdoor pond condition was significantly higher than that of crab reared in indoor closet (P<0.05) . The environment conditions made no significant influence to the expression of MIH and RXR genes, but significant difference was found in CHH, EcR and GIH genes between two environments (P<0.01) ; there was significant expression difference between all five genes ( RXR, CHH, EcR, GIH and RXR ) among different stages of larva crab. Meanwhile, significant interaction effects (P<0.01) between rearing environments and development stages were found in four genes (RXR, CHH, EcR and GIH), but not found in MIH gene (P>0.05). Furthermore, the positive co-expression were detected for the genes of MIH, GIH, CHH genes, but negative expression were found between the RXR and GIH genes, which regulate molting and growth in crab.