title: [Specific expression of beta-actin during spermatogenesis in rats].
abstract: OBJECTIVE
  To screen the stage-specific expression proteins during rats spermatogenesis, and to investigate the beta-actin expression and localization in the tissues of rat testicular.
  
  
  METHODS
  Highly enriched type A spermatogonia, pachytene spermatocytes and round spermatids were isolated by STAPUT method (sedimentation velocity at unit gravity, with 2% - 4% BSA gradient in DMEM/F12 medium) respectively to get the total proteins. The difference of protein expression between the three kinds of cells was analyzed by two-dimensional electrophoresis. Then the distribution of beta-actin in rat testicular tissues was investigated using specific anti-beta-actin antibodies by immunohistochemical method.
  
  
  RESULTS
  beta-actin was identified as a stage-specific expression protein by two-dimensional electrophoresis. beta-actin protein was more strongly expressed in type A spermatogonia and pachytene spermatocytes, but not in round spermatids. The immunohistochemical results showed that beta-actin was mainly located in the cytoplasm of type A spermatogonia and pachytene spermatocytes and in the nuclei of nearly mature spermatids.
  
  
  CONCLUSIONS
  beta-actin protein is a stage-specific expressed protein and may play an important role in spermatogenesis.
authors.affiliation: National Research Institute for Family Planning, Beijing 100081, China.
authors.forename: Yi-ming
authors.initials: YM
authors.lastname: Cheng
authors.forename: Xi-quan
authors.initials: XQ
authors.lastname: Shi
authors.forename: He-ming
authors.initials: HM
authors.lastname: Yu
authors.forename: Yan-wan
authors.initials: YW
authors.lastname: Wu
authors.forename: Meng-chun
authors.initials: MC
authors.lastname: Jia
mesh_terms: D000199:Actins / Q000096:biosynthesis*; D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional; D008297:Male; D013058:Mass Spectrometry; D051381:Rats; D017207:Rats, Sprague-Dawley; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000166:cytology / Q000378:metabolism*
chemical_list: D000199:Actins