Effects of Scrotal Heating on Sperm Surface Protein PH-20 Expression in Sheep

Jean S. Fleming, Fu Yu, Robin M. McDonald, Stuart A Meyers, Grant W. Montgomery, John F. Smith, Helen D. Nicholson

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


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°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.

Original languageEnglish (US)
Pages (from-to)103-114
Number of pages12
JournalMolecular Reproduction and Development
Issue number1
StatePublished - May 2004


  • Gene expression
  • Haploid
  • Ovine
  • PH-20
  • Spam1
  • Sperm
  • Testis

ASJC Scopus subject areas

  • Genetics
  • Developmental Biology
  • Cell Biology


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