Screening Of Key Reproductive Hormones And Differential Proteins In Early Pregnancy Diagnosis Of Sheep

Pregnancy diagnosis plays an important role in reducing non-pregnant rate,implementing precision management,reducing feeding cost and improving reproductive efficiency.However,the present standard using reproductive hormone for the diagnosis of early pregnancy is not unified,and few proteomics research on the diagnostic of early pregnancy in ewes have been reported.Based on the investigation of the changes of major reproductive hormones in pre-and post-estrus Hu sheep,the differences in serum reproductive hormone and pregnancy-related glycoprotein(PAG)levels between early pregnancy and non-pregnant ewes were evaluated.The key reproductive hormones or differential proteins for early pregnancy diagnosis were also screened by proteomics method.The results could provide a basis for early pregnancy diagnosis.Twenty estrus ewes(F group)were selected but not mated.Blood samples were collected at the time of sponge insertion,withdrawal and estrus period.The progesterone(P4)and estradiol(E2),follicle stimulating hormone(FSH)and luteinizing hormone(LH)were evaluated using ELISA.Blood samples were collected from 60 estrus ewes(Group II)on day 0,7,14,18,22,26,30 after AI.The P4,E2,FSH,LH,estrone sulfate(E1S)and pregnancy-associated glycoprotein(PAG)were measured by ELISA.B-ultrasound diagnosis was carried out to detect pregnant and non-pregnant ewes.According to the results of B-ultrasound diagnosis,ewes were divided into pregnant group(P group)and non-pregnant group(N group).The differential proteins of pregnancy were determined by proteomics method.The results showed:1.The highest serum P4 was observed in estrus period.It was significantly higher than that of the sponge insertion and withdrawal period(P < 0.05).The serum E2,FSH and LH concentrations in the estrus period were significantly higher than those of the sponge insertion period(P < 0.05).2.The serum P4 and E1 S concentrations on day 14 and 18 after mating in the P group were significantly higher than that those of the F group and N group(P < 0.05).These on day 22,26 and 30 after mating were significantly higher than that of the N group(P < 0.05).The concentration of serum PAG on day 14 in group P was significantly higher than that in group F and group N(P < 0.05),and it on day 22,26 and 30 after mating was significantly higher than that in group N(P < 0.05).The P4 concentration on day30 after mating was higher than 16.5 ng/m L,the E1 S concentration was higher than 1.7 ng/m L on day 30,and the PAG concentration is above 42 ng/m L on day 30.Therefore,they could be used as the threshold standard for the diagnosis of early pregnancy in ewes.3.In this experiment,four differential proteins were screened by proteomics method: fibrinogen like 1(FGL1),protein disulfide-isomerase(PDIA3),myosin heavy chain 9(MYH9)and matrix gla protein(MGP).The up-regulated FGL1 and down-regulated PDIA3,MYH9,and MGP can be used as key proteins for early pregnancy diagnosis,which lays a foundation for further study of differential proteins in early pregnancy of ewes.