167 INFLUENCE OF THE SPERM SELECTION METHOD AND FERTILIZATION DOSES ON CHROMOSOMAL ABNORMALITY RATES OF 4-DAY-OLD BOVINE EMBRYOS
S. Demyda Peyrás A B , L. J. De Luca A and M. Moreno Millán BA University of Lomas de Zamora, Buenos Aires, Argentina;
B University of Cordoba, Córdoba, Spain
Reproduction, Fertility and Development 24(1) 195-195 https://doi.org/10.1071/RDv24n1Ab167
Published: 6 December 2011
Abstract
This cytogenetic study was conducted to quantify the incidence and type of chromosomal abnormalities on in vitro-produced bovine embryos. Eight groups of 150 in vitro-matured oocytes were IVF for 18 h. Final sperm concentrations of 1 × 104, 1 × 105, 1 × 106 and 1 × 107 cells mL–1 selected by the washing method or the swim-up method were utilised. Presumptive zygotes were cultured for 96 h, collected and fixed individually for analysis. Chromosomal complements of 447 embryos were determined by Giemsa staining and direct observation. Rates of haploidy, diploidy, aneuploidy and polyploidy were determined individually. The incidence of chromosomal abnormalities in embryos derived by IVF with 1 × 104, 1 × 105 and 1 × 106 cells mL–1 did not differ regardless of the sperm preparation method. Polyploidy incidence was strongly increased (P < 0.01) at a concentration of 1 × 107 cells mL–1 in both sperm treatment groups. The fertilization rate obtained with a 1 × 104 cells mL–1 sperm dose in both selection methods and with a 1 × 105 cells mL–1 sperm dose with the washing selection method were significantly lower (P < 0.05) than those obtained with the other sperm concentrations. The lowest fertilization rates (P < 0.05) were achieved with the lowest dose and the washing sperm selection technique. Acceptable fertilization rates with low chromosomal abnormalities can be achieved with a final sperm concentration of 1 × 105 cells mL–1 or higher regardless of the sperm selection method used. In conclusion, the sperm selection method did not result in differences in the chromosomal abnormality rates on in vitro-produced bovine embryos. The use of high sperm concentration doses produced unacceptable rates of such abnormalities regardless of the sperm selection method. The use of very low sperm doses produced unacceptable fertilization rates, especially when the washing sperm selection method was performed.
Sebastián Demyda Peyrás is an MAEC–AECID grantee.
