Effects Of Chemicals On Several Genes Involed In Final Oocyte Maturation Of Common Carp (Cyprinus Carpio)

Regulation of oocyte development is always the focusof fish reproduction physiology.The survival rate of eggs has been a main evaluating factor in aquaculture,and final oocyte maturation is the key step to successful spawning and fertilization.In present study,we studied the effects of chemicals on several genes related in final oocyte maturation of common carp by using in vitro oocyte culture and real-time quantitative PCR.The results are as follows:1.The GVBD rate of oocytes incubated with different chemicals were analyzed.The results shows that DHP can induce final oocyte maturation of common carp directly.DES has the same effect as well for it maybe the analog of DHP.DEHP alone has certain inhibitory effect or no effect on final oocyte maturation of common carp,but this effect can be inhibited by DHP.2.Reference genes of final oocyte maturation incubated with different chemicals were validated.The results indicate that EF1? is the most stable expressed reference gene when incubated with DHP or DES,while gapdh is the most stable expressed reference gene when incubated with DEHP.The m RNA expression of luteinizing hormone receptor(LHR)during final oocyte maturation induced by DHP was normalized by 6 candidate reference genes respectively,and the relative expression was highly varied with different reference gene which means stable expressed reference gene selection is critical for all q PCR analysis to get accurate target gene m RNA expression information.3.The m RNA expression of several genes involved in final oocyte maturation of common carp by DHP induction studied.1)The expression of cyp19?m PR??LHR?cdc2 and cyclin B increased significantly with the extension of DHP incubation.The expression of 20?-HSD was very low during the whole DHP exposure,while the expression of IGFBP2 increased firstly and then decreased.2)When the oocyte were exposed to different concentration of DES,except for cdc2 and cyclin B,other genes were all induced by 0.1?mol/L DES.The expression of cyp19?LHR?m PR??cdc2?cyclin B and IGFBP2 were induce by 1?mol/L DES,and 2?mol/L DES induced the expression of m PR??LHR?cyp19 and IGFBP2.3)DEHP alone inhibited the expression of all genes,and the effects gets stronger as the concentration became higher;however,the inhibitory effect was weaken when added DHP,in other words,DHP has dominant position.When simultaneously exposed to DEHP and DHP,DEHP inhibition to these genes would be weakened relatively.4.The coexpression relationship of genes involved in final oocyte maturation of common carp was analyzed by calculating Pearson correlation coefficient.20?-HSD,m PR? and LHR were significantly co-expressed at 12 h exposure of DHP,DES and DEHP plus DHP.m PR?,cdc2 and cyclin B showed same co-expression relationship.The coexpression relationship of these genes was strongly related to their functions in final oocyte maturation.