Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Chromosome analysis of bovine oocytes cultured in vitro | Genet Sei Evol 1991 23 191-196 Elsevier INRA 191 Original article Chromosome analysis of bovine oocytes cultured in vitro BR Yadav WA King KP Xu JW Pollard L Plante University of Guelph Ontario Veterinary College Department of Biomedical Sciences Guelph Ontario Canada NIG 2W1 Received 18 July 1990 accepted 4 April 1991 Summary - Oocytes n 836 collected from slaughtered cows of unknown reproductive background were matured in vitro and subjected to chromosome analysis. In all 744 89 resumed meiosis and 603 72 reached metaphase II stage. The non-disjunction rate and disploidy rate was and respectively. The incidence of non-disjunction in in vitro matured bovine oocytes is similar to that reported for other domestic species. oocytes meiosis non-disjunction chromosome bovine Resume - Analyse chromosomique d ovocytes bovins cultivés in vitro. Les ovocytes utilises lors de cette étude furent prélevés sur des ovaires de vaches de statut reproductif inconnu. La maturation de ces ovocytes n 836 fut effectuee in vitro et suivie de leur fixation en vue d une analyse chromosomique. Au total 744 89 présentèrent une reprise de méiose et 603 72 atteignirent le stade de metaphase II. Les taux de non-disjonction et de diploĩdie étaient de 5 8 et 10 7 respectivement. L incidence de la non-disjonction chez les ovocytes bovins matures in vitro est similaire à celles déjà signalées chez d autres espèces domestiques. ovocytes I méiose non-disjonction chromosome bovin INTRODUCTION Since observations of the chromosomes of domestic cattle were first reported by Krallinger in 1927 extensive studies have yielded a wealth of information pertaining to the normal karyotype. In addition a large number of individuals with abnormal karyotypes involving anomalies of chromosome structure and number have been reported for review see Popescu 1989 . Present address NDRI National Institute of Animal Genetics National Bureau of Animal Genetic Resources NDRI Campus Karnal-Haryana 132001 India .
