Oviductal co-culturecell did not reduce the rate of chromosomal abnormalities in in vitro produced bovine embryos

DEMYDA-PEYRÁS, S.; PERAL GARCÍA, P.; MORENO MILLAN, M.

Austin

Congreso; 43th International Embryo Technology Society Conference; 2018

International Embryo Technology Society

One of the major causes of embryo failure on IVP cattle embryos is their increased rate of chromosomal abnormalities. It was demonstrated that they can be increased by the pre and post environmental conditions of culture, such as the culture media and supplementation and culture atmosphere among others. Furthermore, it was suggested that the percentage of chromosomal abnormalities detected could be used as an indirect methodology to evaluate the embryo ?stress? during culture. The use of oviduct cells in co-culture was employed as a technique that improves the embryo quality in different culture systems in cattle, probably by modulating the variations in the embryo environment or detoxifying the culture media. For that reason, we aimed to determine if the use of an oviductal co-culture system could reduce the percentage of chromosomal abnormalities in in vitro produced cattle embryos. Oviductal cells were obtained from abattoir oviducts, plated and cultured in TCM-199 media following standard procedures. COC were also obtained from the abattoir and matured in a standard media (TCM199, with glutamine, pyruvate, FSH, LH and antibiotics) for 20 h (38.5ºC,5% CO2). Matured oocytes were fertilized in IVF-TALP with 1x106 spz/mL (previously selected through a 45%-90% Percoll? gradient) for 18h using the same conditions. Presumptive zygotes (n=653) were divided into two groups and cultured in the mSof medium for 72h, with (SOV) or without (SOF) the addition of oviductal cells. In total 108 embryos were successfully karyotyped following our standard laboratory techniques. Chromosomal numerical abnormalities were evaluated by direct observation at x1250 magnification in a bright field microscope using a simple giemsa staining. The percentage of diploid embryos (54/58 in SOV and 47/53 in SOF) and abnormal embryos (4/58 in SOV and 6/53 in SOF) were non-significant (p>0.05; Z-score test for two population proportions). Our results suggest that the use of oviductal cells as a co-culture supplementation in IVP cattle embryos do not improve the percentage of chromosomal abnormalities detected.