| With the continuous improvement of feeding and management condition,there is a hot topic on exploiting the ovarian reserve,increasing the rate of ovulation and fostering high reproductive pigs to improve productivity.FSH,can active the downstream PI3K/AKT signaling pathway mediate by its receptors,which can promote ovarian development.AKT2 is a key enzyme for this signaling pathway.APPL1,as an adapter protein,may interacts with some domains of FSHR,can affect the activity of AKT2 and improve the proliferation and differentiation of granulosa cells and regulate follicular atresia finally.In this study,the unpregnant American large white sows,the unpregnant Danish large white sows,the unpregnant Wannan black sows and pregnant Wannan black sows were used as experimental animals.The number of born alive,the ovarian weight and development were compared among breeds.Thelocalization and mRNA quantitative expression of FSHR,AKT and APPL1 were investigated by immune histochemistry and RT-PCR respectively.The results were as follows:(1)Number of born alive of Wannan black sows and Danish large white sows were significantly higher than those of American large white sows(P<0.01).(2)The ovarian weight of unpregnant Danish large white sows was significantly higher than that of the other three groups(P<0.01).(3)The staining of HE shows that: The rate of early and late atresia follicles of pregnant Wannan black sows were significantly higher than that of the other three groups(P<0.01).The rate of late atresia follicles of unpregnant American large white sows>that of unpregnant Danish large white sows>that of unpregnant Wannan black sows(P<0.01).(4)FSHR,AKT2 and APPL1 mainly distributed in the primary follicles,granulosa cells and mesangial cells of healthy follicles,but weakly distributed in the early atresia follicles and less weakly or no distributed in the late atresia follicles.The expressive intensity of FSHR,AKT2 and APPL1 of unpregnant American large white sowswere significantly less than those of other three groups in the luteal.(5)Mean intensity and IOD:(1)The mean intensity of FSHR in the healthy follicles of unpregnant Wannan black sows was significantly higher than that of other three groups(P<0.05),the IOD of FSHR in the healthy follicles of unpregnant American large white sows was significantly higher than that of the other three groups(P<0.05).The mean intensity of FSHR in late atresia follicles ofWannan black sows were significantly higher than that of the two other groups(P<0.05).The IOD of FSHR in late atresia follicles ofunpregnant Wannan black sows was significantly higher than that of the other three groups(P<0.05).(2)The mean intensity of AKT2 in the healthy follicles of unpregnant Wannan black sows was significantly higher than that of unpregnant American large white sow s(P<0.05).The IOD of AKT2 in the healthy follicles of unpregnant Danish large white sows>that of unpregnant American large white sows>that of unpregnant Wannan black sows(P<0.05).The IOD of AKT2 in early atresia follicles of unpregnant Danish large white sows and pregnant Wannan black sows were significantly higher than that of unpregnant Wannan black sows(P<0.05).The mean intensity of AKT2 in late atresia follicles of pregnant Wannan black sows was significantly lower than that of the other three groups(P<0.05).The IOD of AKT2 in late atresia follicles of pregnant Wannan black sows were significantly higher than that of the other three groups(P<0.05).(3)The mean intensity of APPL1 in the healthy follicles of unpregnant Wannan black sows were significantly lower than that of the other three groups(P<0.05).The IOD of APPL1 in the healthy follicles of unpregnant American large white sows were significantly higher than that of the other three groups(P<0.05).The mean intensity of APPL1 in late atresia follicles of pregnant Wannan black sows and unpregnant Danish large white sows were significantly higher than that of other two groups(P<0.05).The IOD of APPL1 in late atresia follicles of pregnant Wannan black sows were significantly higher than that of unpregnant American large white sows and unpregnant Wannan black sows(P<0.05).(4)The IOD of FSHR,AKT2,APPL1 in the healthy follicles of each group were significantly higher than that in the early or late atresia follicles(P<0.01).(6)The expression of FSHR,AKT2,APPL1 mRNA in ovary of unpregnant Wannan black sows were significantly higher than that of the other three groups(P<0.01);The expression of AKT2,APPL1 mRNA in ovary of pregnant Wannan black sows were significantly lower than that of the other three groups(P<0.01);The expression of FSHR,AKT2 mRNA in ovary of unpregnant American large were significantly higher than that of unpregnant Danish large white sows(P<0.01).The expression of APPL1 mRNA in ovary of unpregnant Danish large was significantly higher than that of unpregnant American large white sows(P<0.01).(7)The expression of APPL1 mRNA in ovary has extremely significant negative correlation with rate of the late atresia follicle(P<0.01);The expression of FSHR mRNA has significant spositive correlation with he expression of AKT2 m RNA in ovary(P<0.05).In conclude:(1)Fecundity of sows was influenced by ovary weight and follicular atresia.(2)FSHR,AKT2 and APPL1 mainly distributed in the granulosa cells of thehealthy follicles,and weekly or no distributed in the late or early atresia follicles.The results suggest that the regulation of FSHR,AKT2 and APPL1 on reproduction may mediated by acting on the granulosa cells of the healthy follicles sites.(3)The difference expression of FSHR,AKT2 and APPL1 exists in different capacity of born alive of sows,which indicates that their expression maybe related with their number of born alive.(4)The negative correlation between rate of follicular atresia and expression of APPL1 mRNA in ovary may prompt that the expression of APPL1 mRNA restrain follicular atresia;The spositive correlation between expression of FSHR and AKT2 mRNA indicate that they synergistically regulate procreation. |
