Postnatal Developmental Changes Of GnRH And GnRHR In The Gastronintestinal Tract Of Jining Grey Goat

Jining Grey goats which originally from China is a unique suede type goat breed and its year-round rut, early maturity. The newborn nanny goat just need 3 months to development to sexual maturity while the ram 4 months. Some individual with earlier sexual development may come into heat in theirs two months, and the estrus cycle continues for 17.50±0.50 days,1-2 days each time. The gestation period is about 147.00±2.50 days, 146 days equally. Jining Grey goats have high reproduction rate. The survival rate of the lamb is as high as 95%. It was placed on the China Sheep Breeds as an excellent local goat breed with the characteristics such as gentle disposition, genetic stability, high adaptive capacity, resistance to forage and high economic value.To study the change of GnRH and GnRHR’s distribution in the gastrointestinal tract with ages can provide necessary theoretical basis to understand the effect of GnRH and GnRHR to animal’s digestive tract. To explore the distribution and development law of GnRH and GnRHR in submandibular gland and pancreas of Grey goat during its postnatal development stages, This experiment uses immunohistochemical method(SABC method) to explore the GnRH and GnRHR positive cells’ distribution characteristics and development laws in submandibular gland and pancreas from birth(0 day) to 180 days. The GnRH and GnRHR positive immune product in the gastrointestinal tract are all located in the cytoplasm, with color of yellow or tan. The negative control have not been dyed. At the 0 day, GnRH positive immune product distribute in the base of rennet fundic gland or between the small intestine villi epithelium and the large intestinal colorectal goblet cells; after 30 days, it started to distribute in the small intestinal epithelial cells and keep the increasing trend. The positive expression of GnRH in the abomasums reached the maximal value at 60 days. And at90 days,it reached the peak in other parts. At the 0 day, GnRHR positive immune product distribute in the epithelial cells of the gastric pit、small intestinal villus、duodenal gland or large intestine mucosa; after 30 days, it started to distribute in the epithelial cells of large intestine mucosa and keep the increasing trend until it reached the maximal value at 90 days. During 0 to 90 days, the IOD of GnRH and GnRHR immunoreactive cells increased significantly(P < 0.01);the IOD of GnRH and GnRHR immunoreactive cells slightly decreased at 90 days afterreaching the peak(P > 0.05). In conclusion, the gastrointestinal tract of Jining grey goat can secrete GnRH in the form of endocrine or paracrine. And GnRH may be mediated by GnRHR,promote the development and maturity of the submandibular gland and pancreas.