Incidence of chromosomal abnormalities in bovine blastocysts derived from unsorted and sex-sorted spermatozoa.
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.
Garcia-Herreros
M
M
School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
Carter
T F
TF
Villagómez
D A F
DA
Macaulay
A D
AD
Rath
D
D
King
W A
WA
Lonergan
P
P
D000818:Animals; D001755:Blastocyst / Q000473:pathology*; D002417:Cattle; D002678:Chimera; D002869:Chromosome Aberrations / Q000196:embryology / Q000662:veterinary*; D046149:Embryo Culture Techniques / Q000662:veterinary; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D005434:Flow Cytometry / Q000662:veterinary; D017404:In Situ Hybridization, Fluorescence / Q000662:veterinary; D008297:Male; D011003:Ploidies; D012732:Sex Determination Analysis / Q000662:veterinary; D012743:Sex Preselection / Q000662:veterinary*; D013094:Spermatozoa / Q000502:physiology*; D014960:X Chromosome; D014998:Y Chromosome