FAS LIGAND EXPRESSION IN THE PORCINE OVIDUCT

Abstract

The expression of Fas/Fas Ligand (FasL) is thought to be involved in the immune privileged status of the testis, cornea and the placenta. The objective of this study was to see whether FasL mRNA was expressed in the epithelium of the porcine oviduct, where spermatozoa, oocytes and developing embryos avoid elimination by the female immune system during the estrous cycle. The distribution of Fas/FasL might provide information about immune privileged sites in the pig oviduct. The gene expression of FasL was detected in the uterotubal junction (UTJ), isthmus and ampulla of the pig oviductal epithelium, during both pre- and post-ovulatory periods, using semiquantitative RT-PCR. FasL mRNA was found in the epithelial cells from the sperm reservoir (UTJ, adjacent
isthmus) and the ampulla during both pre- and post-ovulation. The level of expression between UTJ and other oviduct segments differed significantly during pre-ovulation (p < 0.05). The densitometry ratios of FasL: β-actin tended to be stronger in the isthmus and the ampulla after ovulation but did not vary significantly. The results indicated for the first time that FasL mRNA is present in the porcine oviduct and might be involved in a Fas/FasL system that mediates the survival of spermatozoa, oocytes and early embryo development.