title: Cytogenetic effects of advanced maternal age and delayed fertilization on first-cleavage mouse embryos.
abstract: It has been shown that both advanced maternal age and delayed fertilization may induce chromosomal anomalies. We therefore examined the combined effects of these two factors on chromosomal anomalies in first-cleavage mouse embryos. We set up normal and (6-h) delayed subgroups in two different age groups (young, 3-4 mo; aged, 9-11 mo) and compared the incidence of chromosomal anomalies. In first-cleavage embryos, egg-derived chromosomes can be distinguished from sperm-derived chromosomes. The incidence of maternally derived aneuploidy was highest in the aged-delayed fertilization subgroup. We therefore conclude that advanced maternal age affects the production of aneuploidy more severely when combined with the effect of delayed fertilization.
authors.affiliation: Department of Hygiene and Preventive Medicine, Yamagata University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sakurada
authors.forename: H
authors.initials: H
authors.lastname: Ishikawa
authors.forename: A
authors.initials: A
authors.lastname: Endo
mesh_terms: D000782:Aneuploidy; D000818:Animals; D002970:Cleavage Stage, Ovum; D005260:Female; D005306:Fertilization; D008098:Litter Size; D008297:Male; D008423:Maternal Age; D051379:Mice; D013997:Time Factors