Spatial and Temporal Gene Expression of Fn-Type II and Cysteine-Rich Secretory Proteins in the Reproductive Tracts and Ejaculated Sperm of Chinese Meishan Pigs

Fibronectin type II and cysteine-rich secretory proteins have been well studied in the murine and human. The present study evaluated CRISP1, CRISP2, CRISP3 and Fn-type II (ELS-PBP1 and pB1) gene expression patterns in ejaculated sperm and reproductive tracts of Chinese Meishan pigs from birth to day 150 of age. In ejaculated sperm, except for ELSPBP1, all others genes studied were detectable. In sexually mature boars and gilts, CRISP1 gene was expressed strongly in whole epididymides, moderate in prostate and weak in seminal vesicle. CRISP2 gene represented extensive distribution along reproductive tracts with highest abundance in testis. CRISP3 gene was expressed highly in prostate and bulbourethral gland, but weakly in testis. ELSPBP1 gene was expressed with highest abundance in cauda epididymides, moderate in corpus epididymides and weak in seminal vesicle and prostate. pB1 mRNA expression was also abundant along reproductive tracts. During the sexual development of boars after birth, these genes showed different expression patterns. CRISP1 and CRISP3 gene expression was high on day 1 and maintained until day 150, while CRISP2 expression was detectable on day 60 with high abundance and maintained until day 90 and dropped on day 150. ELSPBP1 showed low expression at birth and increased significantly on day 30 (p < 0.05) and then kept static until day 150. pB1 gene displayed moderate expression from birth to day 30 and increased significantly on day 60 (p < 0.05) and maintained at high level until day 150. Collectively, CRISP and Fn-type II genes were expressed extensively along genital tracts, and most of them showed mRNA signal in ejaculated sperm. The expression of CRISP1 and CRISP3 genes in Meishan boar was not age-dependent, while CRISP2 and pB1 gene expression was parallel with sexual development. Their unique gene expression patterns may shed light on the mechanism for the high prolificacy of Meishan pigs.