The Study On Gonadotrophin And The MRNA's Abundance Of Its Receptor In Goat

Improving the prolificacy of goat is one of way to increase the efficiency of the meat-goat industry. In this study, different prolificacy Jizhong goats were studied, which is a high prolific breeding located in the middle region of Hebei province. Several biochemical and molecular biological indexes related to the little size trait was studied; the indexes are concentration of gonadotrophin hormone in plasma, mRNA aboundance of FSHR(follicle stimulating hormone receptor) and LHR (luteinizing hormone receptor), polymorphism for the exonll of LHR gene were screened with SSCP. The results were showed as follows:1. With the RIA(radioimmunoassay), we assayed the concentration of FSH and LH in plasma. The results show that one estrous cycle for Jizhong goat lasts for 16.07±1.06 days. In an estrous cycle, there are two FSH hormone concentration peaks companying with LH peak. The areas surrendered by the curve of FSH concentration and the time axis positive correlated significantly with the number of antral follicles on the ovary during day3-day3.5 and day14-day16(P=0.03 and P=0.02 respectively), the correlation coefficients were 0.86 and 0.87 respectively. But during day7-day9, the area negative correlated significantly with the number of the antral follicles on the ovary (P=0.04), the correlation coefficients was -0.83.2. Using semi-quantity RT-PCR, the mRNA abundance in the ovary of FSHR gene and LHR gene was assayed in Jizhong goats. The result suggested: during oestrum, for the prolific Jizhong goats, the mRNA abundance of FSHR gene in ovary (0.6206±0.0539) were singnificant higher than low ones (0.5410±0.0095, P=0.04). This is opposite to the results obtained from the FSH concentration in plasma (1.14±0.43mIU/mL and 2.18±2.02mIU/mL respectively). This result show the tendence that the abundance of FSHR mRNA express in high prolific goats were high than low prolific goat. Combing the effect of FSH,FSHR in follicles' development, we deduce that FSHR mRNA's expression is one of the factor that influence the prolificacy of goat. The mRNA's abundance of LHR in ovary in prolific Jizhong goat (0.8714±0.1716) were higher than low prolific Jizhong goat (0.7709±0.0654), but it wasn't reach significant level (P=0.39), Same results obtained from the LH concentration in plasma (7.02±1.93mIU/mL and 6.07±2.12mIU/mL respectively) The result suggested the abundance of LHR mRNA is one of the potential reason of prolificacy in Jizhong goat., but it need more study to support it.3. With the sequence from GenBank, five primers were designed to amplification Exon11 of LHR gene, Polymorphism was screened with SSCP, no mutation was found in this region.