Glucose controls sex-related growth rate differences of bovine embryos produced in vitro.

The objective of this study was to determine whether the presence of glucose in the culture medium causes more growth of male embryos than of female embryos in cows. Oocytes matured and fertilized in vitro were cultured from 24 to 48 h after insemination in CR1aa medium with or without 5.56 mmol glucose l-1.

Survival of biopsied and sexed bovine demi-embryos.

The viability of sex-diagnosed bovine demi-embryos was investigated after transfer. Day-7 morulae and blastocysts were subjected to splitting and biopsy in PBS + 4mg/ml polyvinylpyrrolidone + 200mM sucrose using a microblade. The biopsy (approximately 2 to 8 blastomeres) was transferred to a tube, and its presence in the tube was verified by examination under a stereomicroscope.