The Rat Epididymis-specific The Gene Esc-615 And Hongres1

The first part of this thesis was "Studies of rat epididymis specifically expressed gene ESc-615". ESc-615, a new member of carboxylesterase superfamily in monkey, is an epididymis specifically expressed gene discovered by our laboratory previously. The homologue of monkey ESc-615 was cloned in rat by screening rat epididymis cDNA library. Its cDNA contained 2147bp nucleatides, the predicted protein contained 575 amino acid residues with carboxylesterase type-B signature and a carboxylesterse type-B activate site. It had 72 % amino acid sequence similarity with monkey ESc-615 . In situ hybridization assay revealed the signal was weak in the initial segment, and became stronger and stronger gradually along the epididymis toward the cauda. The expression of rat ESc-615 was up-regulated by androgen. To further elucidate its function in sperm maturation and fertilization at its protein level, we got antisera against a peptlde, the peptide contained 310 amino acid residues. Immunostaining showed rat ESc-615 was a secreted protein, and could bind with sperm. This indicated the function of rat ESc-615 might be associated with sperm function in male fertility.The second part of this thesis was "Cloning of the rat epididymis specifically expressed gene HongrESl". HongrESl were cloned by screening rat epididymis cDNA library and 5'RACE. It was specifically expressed in cauda epididymis. The size of its full length cDNA was 1590bp, and the size of its predicted protein which had serpin conserved domain was 415 amino acid residues. Structure analysis found HongrESl was a new member of serine protease inhibitor (serpin) family, In situ hybridization showed HongrESl was expressed in the rear part of the cauda epididymis. The function of HongrESl in male reproduction remains to be studied.We got another cauda epididymis specifically expressed gene (HongrES2) together with HongrES1 when screening rat cDNA library. The sequence of HongrES2 remains to be confirmed.