Attachment and Trophoblastic Outgrowth of Swine Blastocysts in Vitro2

Abstract

The objective of this study was to devise a culture system which would support the development of swine blastocysts in vitro. One-hundred-twenty blastocysts were collected from Yorkshire × Hampshire gilts slaughtered 6 to 9 days after the onset of estrus. Blastocysts were cultured in Nutrient Mixture F-10 (Ham's F-10) and Minimum Essential Medium (MEM), each medium supplemented with 0, 10, or 40% porcine serum over substrates of plastic or collagen. Culture was conducted at 37 C in a humidified atmosphere of 5% CO₂ in air and blastocyst development rated numerically at the cessation of culture. While blastocysts attached in all treatments, only slight trophoblastic outgrowth and no differentiation of the inner cell mass (ICM) was observed in serum-free media. In media containing serum, however, blastocyst development was significantly greater (P<.005) with some blastocysts showing extensive trophoblastic outgrowth as well as two-layer differentiation of the ICM. No significant difference was observed between the two media or substrates and development in 40% serum was not significantly different from 10% serum (P>.10). The results suggest that in vitro development of swine blastocysts is similar to the early post-blastocyst development of mouse embryos in vitro. Copyright © 1978. American Society of Animal Science . Copyright 1978 by American Society of Animal Science.