Location And Expression Of GHR、IGF-IR、INSR And PRLR In The Mammary Gland Of Jining Gray Goat During Postnatal Development

Jining Gray Goat is a high prosperity goat breed and has the characteristics of its perennial estrus, early sexual maturity, high reproduction rate which located in the southwest region of Shan Dong province. The puberty of ewes begin at 60 days of age and sexual matyrity at 90 to 120 days of age, the average lambing rate is as high as 283 percent. The mammary glands of mammals plays an important role in the survival of a species, it is the organs that can provide nutrition for the young generation, the nutrient supply sub matrix generation utilization. The growth and development of mammary gland and its physiological functions are dependent on a variety of related endocrine hormones and growth factors work together.In order to explore the distribution and expression of GHR、IGF-IR、INSR and PRLR proteins at the different ages in mammary gland of Jining Gray Goat during postnatal development. HE staining was used to observe the organizational structure of the mammary gland during postnatal development. The SABC immunohistochemical staining was used to observe the localization of GHR、IGF-IR、INSR and PRLR in the mammary gland of different ages during postnatal development. The abundance of GHR mRNA 、 IGF-IR mRNA and INSR mRNA was detected by the real time fouorescence quantitative PCR. Western Blot was used to detect the protein fragment size of GHR、IGF-IR and INSR. The results showed that:Western Blot we find that the protein specific fragments of GAPDH、GHR、IGF-IR and INSR were respectively found in 36 kDa 、 70 kDa 、 55 kDa and 50 kDa in mammary gland;Immunohistochemistry showed that, positive cells of GHR、IGF-IR、INSR and PRLR in the mammary gland located in the cytoplasm of the ductular epithelial cells 、 blood vessels endothelial cells and stromal cells, occasionally in the cell nuclei. GHR and IGF-IR hadsimilar variations, but the expression of IGF-IR was less than that of GHR. From the birth day to 60 days, the optical density in the immunopositive cells of GHR and IGF-IR was rapidly rising(P<0.01), 60 to 90 days declined, reaching the pick at 120 days, then following by a decreased trend. The trends of the optical density in the immunopositive cells of GHR mRNA and IGF-IR mRNA were similar with that of the expression of GHR and IGF-IR. From the birth day to 60 days, GHR mRNA and IGF-IR mRNA were increasing, reaching the pick at60 days(P<0.05), decreasing at 90 days, then reaching the second pick at 120 days, followed by decreasing. From the birth day to 30 days, the expression of INSR positive cells and its average integral optical density increased(P<0.05), 60 to 90 days of ages decreased, then increasing at 120 days and 150~180 days were stable at a high expression level. The trends of INSR mRNA were similar with that of the expression of the average integral optical density in the immunopositive cells of INSR. The average optical density of the PRLR positive cells was relatively low at the birthday, from the 30 days of age, the expression of PRLR increased(P<0.05), 30 to 90 days of age has been in a steady increase(P>0.05), 120 days rapidly rising(P<0.01), then 150~180 days of age in a stable state of decline, but the difference was not significant(P<0.05), and maintained at a high level. Conclusion: GHR、IGF-IR、INSR and PRLR can work together to control the growth and development of mammary gland. The puberty(60d) and sexual maturity period(120d) maybe the fastest period of mammary gland development during postnatal development. The structure of mammary gland gradually improved after sexual maturity, which prepare for future functional mammary gland development during pregnancy.