OBJECTIVEGiven the fact that the Attractin protein express widely in the testis of mature male rat, this paper aims at studying the distribution of the Attractin protein and Attractin mRNA in the testicular tissue of rats of different ages.

METHODSTestes and epididymides were obtained from newborn (8 hours after birth), prepubertal (5 days), pubertal (20 days), postpubertal (50 days) and mature (70 days) Wistar rats; the tissues were fixed and the Attractin protein and mRNA detected respectively by immunohistochemical and in situ hybridization techniques.

RESULTSThe Attractin protein and mRNA expressed respectively within Leydig cells, primitive spermatogonia, primary spermatocytes, spermatids, Sertoli cells and peritubular myoid cells. The Attractin protein stain was mainly located on the cell membrane and cytoplasm, and Attractin mRNA distributed in the nucleus and cytoplasm. There was no immunopositive staining in spermatozoa and epididymides.

CONCLUSIONThe Attractin protein and Attractin mRNA are both expressed widely in the testis of rats of different ages. It suggests that the rat testis has the ability of synthesizing the Attractin protein throughout sexual development, but its physiological function and biochemical mechanism yet remain to be further studied.