In the pig, the blastocyst becomes ovoid and then tubular before rapidly elongating into a filamentous shape on day 11 of pregnancy. This morphological change is believed to maximize contact between the embryo and the uterine surface for fetal–maternal nutrient exchange, as well as to inhibit the endometrial production of luteolytic prostaglandin F2α (1). The fast elongation process is accompanied by maximal expression and secretion of conceptus-specific interleukin 1β (IL1B; IL1B2, a paralog of IL1B) (2). The function of IL1B2 is unknown. In a recent PNAS paper, Whyte et al. (3) demonstrate that deletion of IL1B2 inhibits conceptus elongation. This finding provides solid evidence for the long-predicted role of IL1B2 in pig conceptus development.
Whyte et al. (3) use Sus scrofa 10.2 (August 2011 release) genome …
↵1To whom correspondence should be addressed. Email: jilongliu{at}scau.edu.cn.
