title: Male-to-male differences in post-thaw motility of rhesus spermatozoa after cryopreservation of replicate ejaculates.
abstract: BACKGROUND
  The efficiency of controlled propagation to produce rhesus monkeys of particular genotypes can be maximized by use of cryopreserved spermatozoa collected from specific males to inseminate appropriate females. But this assumes that semen from males with different genotypes can be cryopreserved with equal effectiveness.
  
  
  METHODS
  To investigate whether spermatozoa from different Macaca mulatta males can be effectively cryopreserved when frozen under identical conditions, we collected and froze semen specimens from 13 adult, fertile males maintained at three primate research centers.
  
  
  RESULTS
  Survival, based on post-thaw motility normalized to the pre-freeze value, was assayed within 30 minutes after thawing; it varied from 50% to 70% but declined thereafter. To examine the response of semen from individual males, we collected and froze three to six ejaculates per male from each of seven males.
  
  
  CONCLUSIONS
  In general, semen from a given male responded reproducibly to freezing, but there were significant differences among males. The cause of these differences among M. mulatta males in post-thaw sperm survival remains unidentified.
authors.affiliation: Department of Biological Sciences, University of New Orleans, Audubon Center for Research of Endangered Species, New Orleans, LA, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Leibo
authors.forename: H Michael
authors.initials: HM
authors.lastname: Kubisch
authors.forename: R Dee
authors.initials: RD
authors.lastname: Schramm
authors.forename: Richard M
authors.initials: RM
authors.lastname: Harrison
authors.forename: Catherine A
authors.initials: CA
authors.lastname: VandeVoort
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000662:veterinary*; D008253:Macaca mulatta / Q000502:physiology*; D008297:Male; D012662:Semen Preservation / Q000662:veterinary*; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology; D013997:Time Factors