Incidence of chromosomal abnormalities in bovine blastocysts derived from unsorted and sex-sorted spermatozoa

• Published in: Reproduction fertility and development Vol. 22; no. 8; pp. 1272 - 1278
• Main Authors: Garcia-Herreros, M, Carter, T.F, Villagómez, D.A.F, MacAulay, A.D, Rath, D, King, W.A, Lonergan, P
• Format: Journal Article
• Language: English
• Published: Australia Collingwood, Victoria: CSIRO Publishing 01.01.2010
• Subjects: Animals; Blastocyst - pathology; Cattle; Chimera; chromosome aberrations; Chromosome Aberrations - embryology; Chromosome Aberrations - veterinary; Embryo Culture Techniques - veterinary; embryos; Female; Fertilization in Vitro - veterinary; Flow Cytometry - veterinary; In Situ Hybridization, Fluorescence - veterinary; in vitro fertilization; Male; Ploidies; Sex Determination Analysis - veterinary; Sex Preselection - veterinary; Spermatozoa - physiology; X Chromosome; Y Chromosome
• ISSN: 1031-3613; 1448-5990
• DOI: 10.1071/rd10052

The aim of the present study was to examine the incidence of chromosomal abnormalities in bovine blastocysts produced by IVF with unsorted, X-sorted or Y-sorted spermatozoa. In Experiment 1, individual blastocysts were processed to examine the incidence of mixoploidy using fluorescent in situ hybridisation. Overall, 80% (44/55) of blastocysts were mixoploid (10/15, 14/15 and 20/25 for X-sorted, Y-sorted and unsorted spermatozoa, respectively; P>0.05). However, the prevalence of abnormal XY chromosome complements was relatively low in all groups; on average, only a small fraction of the total nuclei per embryo appeared polyploid (1.64%, 5.62% and 6.0% for X-sorted, Y-sorted and unsorted spermatozoa, respectively). Interestingly, 20% (5/25) of blastocysts derived from unsorted spermatozoa were found to be chimeric (XX/XY). In Experiment 2, chimeric embryos were detected among the blastocysts derived from two of five sires tested. In addition, one chimeric blastocyst was detected among nine in vivo-derived blastocysts obtained following AI. In conclusion, based on the results of the present study, the incidence of chromosomal abnormalities did not different between blastocysts derived from sex-sorted or unsorted spermatozoa. In addition, the occurrence of mixed sex chimeras was not limited to a single sire and was not unique to blastocysts derived from IVF.