K. Bredbacka et P. Bredbacka, IN-VITRO PRODUCTION OF CATTLE BLASTOCYSTS IN CHEMICALLY-DEFINED MEDIUM WITH OR WITHOUT INSULIN SUPPLEMENTATION, Agricultural and food science in Finland, 5(5), 1996, pp. 509-514
In this study we evaluated the use of a chemically defined medium in t
he production of blastocysts from bovine oocytes fertilized in vitro.
As culture medium we used CR1-PVP, a modification of CR1aa medium with
bovine serum albumin replaced by polyvinylpyrrolidone. After 168 h of
culture (192 h after insemination) 8.7%, 10.5 and 12.8% of the cleave
d embryos developed to the blastocyst stage in the presence of 0, 2 or
200 nM insulin, respectively. The supplementation of 200 nM insulin t
ended to increase cell numbers in morulae and blastocysts (P=0.10). It
is concluded that CR1-PVP can be used as a chemically defined medium
in the production of blastocysts from bovine 1-cell embryos. However,
further modifications are needed, and the insulin concentrations used
may be below the optimum for blastocyst production.