title: A cytogenetical study of 7-day-old bovine embryos of poor morphological quality.
abstract: Seven-day-old embryos were collected from Canadian Holstein and Ayrshire heifers after superovulation with pregnant mare's serum gonadotropin (PMSG) or follicle-stimulating hormone (FSH). A total of 103 morphologically abnormal (type C) and 23 morphologically normal (type A) embryos were cytogenetically analyzed after 4, 20-24, or 44-48 h of culture in enriched phosphate-buffered saline or Eagles minimum essential medium. Twenty-one of 23 (91.3%) type A and 75 of 103 (72.8%) type C embryos had cells in metaphase. Among the 21 type C embryos produced by PMSG stimulation, 17 (80.9%) could be analyzed: 6 were mixoploid (two 2n/3n, three 2n/4n, one 2n/6n), 2 were aneuploid (61 XXY), and 9 were diploid. Among the 82 type C embryos produced by FSH stimulation, 58 (70.7%) could be analyzed: 6 were mixoploid (one n/2n, one 2n/3n, three 2n/4n, one 2n/4n/8n), 2 were polyploid (4n), and 50 were diploid. No abnormalities were observed in the type A embryos.
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics*; D000013:Congenital Abnormalities / Q000196:embryology* / Q000235:genetics; D004622:Embryo, Mammalian / Q000166:cytology*; D005260:Female; D005640:Follicle Stimulating Hormone; D006064:Gonadotropins, Equine; D007621:Karyotyping; D008940:Mitotic Index; D009924:Organ Culture Techniques; D013480:Superovulation
chemical_list: D006064:Gonadotropins, Equine; D005640:Follicle Stimulating Hormone