Chromosome analysis of mouse zygotes produced by intracytoplasmic injection of spermatozoa exposed to acrosome reaction inducing agents methyl-beta-cyclodextrin and calcium ionophore A23187.
OBJECTIVE
This study was performed to investigate whether removal of cholesterol from the plasma membrane and collapse of the acrosome can prevent structural chromosome aberrations of paternal origin in mouse zygotes produced by intracytoplasmic sperm injection (ICSI).


METHODS
Mouse spermatozoa were treated with methyl-beta-cyclodextrin (M beta CD) to remove cholesterol from the plasma membrane and with calcium ionophore A23187 to collapse the acrosome. Chromosomes of zygotes derived from M beta CD- and ionophore-treated spermatozoa were analyzed at the first mitotic metaphase.


RESULTS
Both chemical agents effectively induced the acrosome reaction. Incidence of structural chromosome aberrations in ICSI zygotes derived from M beta CD-treated spermatozoa was similar to that in zygotes produced by in vitro fertilization (IVF) with the same spermatozoa, but significantly lower compared to ICSI zygotes derived from acrosome-intact spermatozoa. Chromosome aberration rates in ICSI zygotes derived from ionophore-treated spermatozoa were evidently high compared to IVF zygotes.


CONCLUSIONS
Induction of the acrosome reaction through cholesterol efflux by M beta CD can prevent chromosome aberrations of paternal origin, while use of ionophore to induce the acrosome reaction exerts detrimental effect on paternal chromosomes in ICSI zygotes.
Tateno
Hiroyuki
H
Department of Biological Sciences, Asahikawa Medical College, 2-1 Midorigaoka-higashi, Asahikawa, 078-8510, Japan. htateno@asahikawa-med.ac.jp
D000177:Acrosome / Q000187:drug effects; D020101:Acrosome Reaction / Q000187:drug effects / Q000235:genetics*; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology*; D002784:Cholesterol / Q000502:physiology; D002869:Chromosome Aberrations / Q000187:drug effects*; D005260:Female; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D051379:Mice; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000187:drug effects*; D018709:Statistics, Nonparametric; D015053:Zygote / Q000187:drug effects / Q000502:physiology*; D047392:beta-Cyclodextrins / Q000494:pharmacology*
D007476:Ionophores; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D000001:Calcimycin; D002784:Cholesterol