Pregnancies following 24‐hour co‐culture of equine embryos on foetal bovine uterine monolayer cells

Abstract

Summary A total of 77 embryo collection attempts from 28 donor mares resulted in 50 embryos (64.9 per cent recovery rate) ranging from Day‐6 morulae to Day‐7 expanded blastocysts. Thirty‐five of these embryos, classified as quality grades 1 and 2, were allotted randomly by developmental stage (Stage‐I, precapsulate and Stage‐II, postcapsulate) to a control group transferred non‐surgically within 1 h to synchronised recipients, and a treated group, cultured on a monolayer of foetal uterine fibroblast cells for 24 h prior to non‐surgical transfer to recipient mares. There was no significant difference in pregnancy rates between Stage‐I and Stage‐II embryos, nor between the control group (53.3 per cent) and the 24 h co‐cultured group (42.1 per cent). The use of a co‐culture system may provide a viable alternative to cryopreservation for the transport of equine embryos from one station to another.

The structure and function of the equine capsule in relation to embryo manipulation and transfer

“…In this regard, it is relevant to recall that when rabbit blastocysts are cultured in vitro the zona pellucida is not lysed and the formation of the neozona is greatly disturbed in the absence of the uterine secretions (Fisher, Denker and Beier 1982). However, it must be acknowledged that the presence or absence of capsular material around equine morulae and blastocysts cultured in vitro is difficult to determine by microscopic examination of fresh specimens, as was emphasised during discussion of embryo culture papers (Freeman et a1 1989;Wiemer, Casey, Mitchell and Godke 1989;Skidmore et a1 1989) at the Second International Symposium on Equine Embryo Transfer. In particular, Skidmore et a1 (1989) have described the de novo formation of a capsule around a blastocyst developing from a morula in vitro.…”

The Effect of Embryo Biopsy and Vitrification on the Development Potential of Equine Embryos

“…Since then, researchers have been able to establish successful pregnancies after biopsy (Huhtinen et al, 1997), culture equine embryos before transfer (Weimer et al, 1989), and develop a commercially available vitrification method (Carnevale, 2006). What has not been accomplished is combining biopsy with vitrification.…”