Chromosomal abnormalities on in vitro produced early bovine embryos: use of homologous follicular fluid supplementation in the oocyte maturation media.

SEBASTIÁN DEMYDA PEYRÁS; JESUS DORADO; MANUEL HIDALGO; LEONARDO DE LUCA; ISABEL ORTIZ; LUISA RAMIREZ; DANIEL ACHA VALLS; MAYTE URBANO; MIGUEL MORENO MILLÁN

Hannover

Congreso; 39th International Embryo Transfer Society Anual Meeting; 2013

IETS (International Embryo Transfer Society)

Chromosomal abnormalities were described as a possible cause of embryo failures in cattle, even more when they are in vitro produced. It is widely demonstrated that post-fertilization culture environment affects the frequency of blastomeric aneuploidies. However, the literature concerning the effect of the oocyte maturation techniques on in vitro produced embryos is scarce. The aim of this study was to determine the effect of homologous bovine follicular fluid (BFF), as a possible replacement of commercial serums, in the appearance of chromosomal abnormalities on early IVF produced embryos. COCs obtained from ovary puncture were maturated in modified bicarbonate-buffered TCM199 media, supplemented with glutamine, sodium pyruvate, FSH, LH, estradiol and gentamicin in four different groups. Two treatments were performed: 1) base media supplemented with BFF, obtained from aseptically from follicles between 4mm and 10mm of diameter (10% and 20%) and 2) the control group; base media supplemented with 10% fetal calf serum (FCS) without BFF. After 20 h of culture at 38.5ºC in a 5% CO2 humid atmosphere, COCs from both treatments were fertilized on IVF media and then cultured for 72h in SOF media, according to our laboratory techniques. A total of 152 early embryos were cytogenetically evaluated following our standard laboratory techniques. Developed embryos were individually fixed onto a slide, disaggregated into blastomeres with acetic acid and stained with giemsa solution. Chromosomal numerical abnormalities were evaluated on each embryo by direct observation at x1250 magnification in a bright field microscope. Results were statistically compared among treatments by expected proportion test. No significant differences (p>0.05) were found between different culture media on the percentages of normal diploid embryos or each kind of numerical abnormalities. According to our results (Table 1), the use of homologous follicular fluid as a supplement on the oocyte maturation media has not influenced the appearance of abnormal complements in the produced embryos compared to the use of FCS. In conclusion, homologous follicular fluid may be considered as valid serum replacement in the maturation media on IVF produced bovine embryos.