Identification and characterization of Wfdc gene expression in the male reproductive tract of the rat.

WFDC (Whey Acidic Protein Four Disulfide Core)-containing proteins have been reported in many species, yet they remain uncharacterized in the rat. In this study, we report the identification and characterization of four rat Wfdc genes, Wfdc6a, Wfdc8, Wfdc11 and Wfdc16. Their expression profile in a variety of tissues including the male reproductive tract is analyzed. Wfdc8, Wfdc11 and Wfdc16 expression is confined to the epididymis, while Wfdc6a is expressed widely. Since gene expression in the male reproductive tract is largely androgen-dependent, Wfdc expression was analyzed in the developing (20-60-day-old) and castrated rats. Their expression pattern in developing rats does not correlate with changes in testosterone. Wfdc genes are, however, down-regulated in castrated adult rats, indicating that their dependence on androgens for expression is more pronounced in the adult than in the developing rat. To test the anti-microbial potential of WFDC8, a recombinant WFDC8 C-terminal protein was produced, which exhibited potent anti-bacterial activity against Eschericia coli. Induction of anti-microbial genes is one of the responses during infections in many organ systems. To determine if WFDCs form the components of male reproductive tract innate immunity, Wfdc8 expression pattern was observed in rats challenged with lipopolysaccharide (LPS). For the first time we report the induction of Wfdc8 gene expression in LPS-treated rats, indicating their contributions to the innate immune functions of the male reproductive tract.