Abstract: The expressions of gnrh1(Gonadotropin-releasing hormone 1), gnrhr(Gonadotropin-releasing hormone receptor) and gtha (Gonadotropin hormone α subunit) were detected in brains of diploid and triploid female rainbow trout Oncorhynchusmykiss (RBT) from 31 days post fertilization(dpf) to 68 dpf, and in gonads of diploid and triploid female RBT from 160 dpf to 450 dpf by Real-time PCR to explore the expressive patterns of pivotal endocrine genes in different ploidy female RBT at various developmental stages.It was found that the expression levels of gnrh1 and gnrhr were significantly elevated in brains of triploid female RBT in early developmental period (P<0.05).However, the expression levels of gtha was found to be significantly low in brains of triploid female RBT (P<0.05), remaining at very low level during the whole test period.There were significantly lower expression levels of gnrh1, gnrhrand gtha genes in gonads during the period of 180-270 dpf than those in initial detection (160 dpf) (P<0.05), being decreased by more than 90% during the period of 360-450 dpf compared with those in initial detection.The findings indicate that the ability to secrete gonadotropin hormone by adenohypophysis in pituitary gland, endocrine hypothalamus-pituitary-gonad (HPG) axis, is hindered in triploid female RBT during early developmental period, which is one of the prime cause of the gonads infertility in triploid female RBT.
2019, Vol. 34 
