The Research Of Some Related Genes Expression And The Hormones Changing Rules Of Postpartum Oestrus Sheep After Induced With Different Nutrition Levels

Xinjiang is a big sheep breeding province in China, the development of sheep breeding industry in xinjiang has been restricted seriously by the sheep’s seasonal breeding traits. The sheep seasonal estrus being controlled by the hypothalamus-pituitary-ovarian(hypothalamic-pituitary-gonadal axis, HPG)system.Nutrition also has a significant effect on the estrus performance of sheep, some researches indicate that the photoperiod is a key factors in the this impact. We take the kazak sheep as research objects, observe the estrous appearances of sheep in their anestrus and detect the changes of the reproductive hormones in their estrus cycle, then combine the expression of key genes of Kisspeptin/GPR54 and TSH/Dio systems to study the relationship between the nutrition level and the photoperiod regulation pathways which induced the estrus characters. Specific methods as follows:(1)the concentrations of progesterone(P4), estrogen(E2), follicle-stimulating hormone(LH) and luteinizing hormone(FSH) in sheep serum were detected by ELISA in the period of anestrus and analysis the change rules of reproductive hormones of kazak sheep in anestrus period. The results showed that, the content of P4 of estrus sheep significantly(P<0.05) lower than the sheep out of estrus, and the content of E2、LH and FSH significantly(P<0.05) higher than the sheep out of estrus in unestrus. a significant change in E2 is feeding sheep Kazakh main signs of estrus,it can be judged, when a significant increase in the Kazakh sheep feeding E2 content in vivo, the physiological state of the Kazakh sheep feeding may estrus state.(2)Compared the key peripheral blood hormone P4, E2, LH and FSH of Xinjiang Hazakh sheep in breeding and non-breeding season to analyse the variation rules by the ELISA method, the results showed that, the P4,E2, LH and FSH level are higher in estrous(P<0.05), the P4 are undulating in estrous period and the E2、LH and FSH displayed pulse like fluctuation. The estrous condition comes at the 10-15 days after weaning in non-breeding season, while the estrous condition in breeding season is lasting for the whole time. The anestrous in non-breeding season depends on the lack of LH and FSH which are not enough to raise the E2 and P4.(3)Raised the nutrition level to induce the estrous in non-breeding season, then compared the key peripheral blood hormone P4, E2, LH and FSH of Xinjiang Hazakh sheep to analyse the variation rules, the research provided the theory basis for hormones for nutritional factors regulating the sheep estrous in non-breeding season. There are 36 sheep divided in two groups, the high nutrition group is added concentrate and the control is in normal feeding condition. Collect the venous blood from the estrous and anestous in non-breeding season and test the P4, E2, LH and FSH by ELISA, the result showed that the estrous rate in high nutrition group is 44%, which is higher than the 16% in control. In the nutrition induced group, the P4,LH and FSH of the estrous sheep are higher in the nutrition group than the control. The P4, LH and FSH are positive and the E2 is negative correlated with the nutrition level. Nutrient levels regulate hormonal changes,which can adjust the estrous of the sheep.(4)IN anestrus raise levels of nutrition, induce estrus Kazakh sheep, combined with kisspeptin / GPR54 and TSH / Dio system detects anestrus Kazakh estrus and anestrus sheep the kiss-1, GPR54, TSH and Dio2genes relative expression level. Using real-time PCR method for analyzed the organizations related genes expression.The results showed that: kiss-1, GPR54, TSH and Dio2 gene are extensive expression, kiss-1,GPR54, TSH, and Dio2 gene in anestrus estrus sheep the relative expression is Significantly higher than anestrus sheep, especially in the hypothalamus(P<0.05); kisspeptin / GPR54 and TSH / Dio system related genes is highly expressed will stimulate the secretion of Gn RH, thus stimulating the secretion of LH and FSH, promote the secretion of E2 and P4, prompting anestrus sheep estrus, indicating that the gene expression and reproductive hormones levels changes is impact for estrus are common, does not exist independently. Nutritional regulation may be crossed with the light cycle regulation or free system in upstream photoperiodic’s regulatory pathways.