School of Veterinary Medicine, University of Cambridge, U.K.
The roe deer is the only ungulate known to exhibit the phenomenon of delayed implantation. Shortly after ovulation in early August, the blastocyst loses its zona pellucida and enters a 5-month period of diapause during which the trophoblast exhibits a minimum of mitotic activity and the inner cell mass remains undifferentiated. Delayed implantation is terminated in early January by the sudden, rapid elongation of the trophoblast and subsequent placental attachment (Short & Hay, 1966). The resumption of rapid embryonic growth appears to coincide with the release of a secretion from the endometrial glands (Aitken et al., 1973; Aitken, 1975). This communication presents the results of an analysis of the carbohydrate content of this secretion.
Eighty-five roe deer shot during the annual Forestry Commission cull at Thetford Chase, Norfolk, provided the material for this study. The uterus was removed from each animal immediately