Fleming JS, Yu F, McDonald RM, Meyers SA, Montgomery GW, Smith JF, Nicholson HD. Effects of scrotal heating on sperm surface protein PH-20 expression in sheep.
Mol Reprod Dev 2004;
68:103-14. [PMID:
15039954 DOI:
10.1002/mrd.20049]
[Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Sperm surface protein PH-20 expression was studied during spermatogenesis in pubertal and adult sheep, using molecular and histological methods. The effects of 24 hr of insulation raising scrotal temperatures to 39 degrees C on PH-20 expression in ejaculated sheep sperm were also determined. A 282 nt cDNA fragment of ovine PH-20 was identified in total RNA extracts of sheep testes, which exhibited 76% identity at the nucleotide level with the equivalent region of the human sequence. Ovine PH-20 mRNA and immunoreactivity were identified only in adult ram testis and not in peri-pubertal ram testis tubules lacking round spermatids, nor in adult sheep brain, pituitary, heart, spleen, lung, liver, kidney, epididymis, or ovary. Ovine PH-20 protein was distributed predominantly on the postacrosomal membrane and was also present on the anterior membrane of the sperm head in fresh, unheated sheep semen. Scrotal heating caused a significant, transient decrease in the percentage of PH-20 immunoreactive sperm, but did not change the pattern of PH-20 staining on the sperm head. The results strongly suggest that ovine PH-20 is postmeiotically expressed in haploid germ cells in sheep testis and is arrayed on the membrane of the mature ovine spermatozoon. Scrotal heating appears to have few effects on PH-20 expression and distribution on ejaculated sperm.
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