Expression And Distribution Of β-Defensin (sBD-2) In The Lung, Intestine And Gential Tract Of Sheep's Fetus

β-defense is one of the endogenous antimicrobial peptides. As an important member of the defensins family,β-defense played an important part in both of innate and acquired immunity, and the other effects have being found with more and more in-depth study on theβ-defense. But the expression and distribution about sheepβ-defensin-2 (sBD-2) mRNA on the development of the sheep's fetal were reported rarely, so we studied on it, the results go as bellow:1.By cloning sBD-2 gene of duodenum of sheep's fetus and comparing the sequences, we found there was a higher degree of homology (above70%) between the sBD-2 cDNA of duodenal of sheep's fetal with the sheep, goats, cattle, pigs and camels'β-defense, and about 50% homology with the human, monkey, mouse'β-defense, and bellow 20% homology with the other species'β-defense.2.Studied on the distribution and location of the sBD-2 in lung, duodenum and uterus of sheep's fetal of 5-month-old by in situ hybridization. The results showed that there were hybridization signal in the cytoplasm of pulmonary alveoli's epithelial cells and endometrial epithelial cells, but no hybridization signal in the proper layer. And there was a strong hybridization signal in the cytoplasm of intestinal epithelial cell, but no hybridization signal in the proper layer. It was pointed out that sBD-2 mRNA distributed in above tissues, and existed in the epithelial cells.3.Studied on the expression changes of sBD-2 mRNA in the lung, intestine, genital duct of sheep's fetus from the 2-month-old to 5-month-old by real-time PCR. The results showed that the expression of sBD-2 mRNA in lung, intestine and genital duct of sheep's fetus from the 2-month-old to 5-month-old increased gradually. It indicated that the expression of sBD-2 was closely related to the fetal stage of development. The expression of sBD-2 mRNA was the highest in intestine, while it was relatively lower in lung and genital duct. This result indicated that the expression of sBD-2 gene existed different distribution in distinct tissues.