Comparative studies of conceptus-endometrial interactions in Large White X Landrace and Meishan gilts.

摘要

18 Meishan and 18 Large White X Landrace (LW X L) gilts were mated to boars of their own breed type and blastocysts and conceptuses were recovered by uterine irrigation. Overall embryo survival among blastocysts recovered on days 11-12 (day of oestrus = day 0) was higher in Meishans than in LW X L gilts (100.7?.0 vs. 69.5?2.1%; P<0.05). Embryo survival was higher on day 11 than on day 12 (98.6?.0 vs. 71.6?2.6%; P<0.05); most of the embryo loss between these days occurred in LW X L gilts. Meishan conceptuses secreted less oestradiol-17beta and radiolabelled protein on both days, but breed differences were not significant. The within-litter variation in the secretion of oestradiol-17beta and radiolabelled protein by individual conceptuses did not differ significantly between breeds. The concentration of epidermal growth factor in uterine rinsings was lower in Meishans than in LW X L gilts on all days studied (P<0.001). However, 2-dimensional polyacrylamide gel electrophoresis and fluorography did not reveal breed differences in the profile of endometrial secretory proteins. Consistent temporal changes in the profile of the conceptus secretory proteins were observed among all LW X L gilts and most of the Meishans. However, 2 of 5 day-12 Meishanconceptuses secreted a major basic protein that was not evident in other conceptus cultures until day 14. Antiviral activity was detected in some cultures of day-13 Meishan conceptuses, but was absent from all day-13 LW X L conceptus cultures. A positive relationship, independent of breed type, was detected between ovulation rate and the incorporation of radiolabel into endometrial secretory proteins.