Cloning of rat interleukin 11 and interleukin 11 receptor alpha chain and analysis of their expression in rat uterus in the peri-implantation period

Studies in mice have shown that interleukin 11 (IL-11) signalling is requir ed for female fertility. In the absence of IL-11, decidualization is marked ly retarded and implantation fails. IL-11 acts via a heterodimeric receptor composed of a ligand-specific receptor alpha chain (IL-11R alpha) and the signalling moiety gp130. This study reports the cloning of genes encoding r at IL-11 and IL-11R alpha. RNase protection was used to demonstrate that ex pression of IL11 is upregulated in the rat uterus at the initiation of impl antation at 5.5 days after mating. Expression of the genes encoding the two receptor components, IL11Ra and gp130, did not change throughout the peri- implantation period. in situ hybridization studies revealed that, as in mic e, expression of IL-11 was high in the primary decidual zone at the time of the attachment reaction, whereas IL11Ra was expressed throughout primary a nd secondary decidua. Conservation of the temporal and spatial expression o f IL-11 and IL-11R alpha in the uterus of the mouse and rat during the peri -im plantation period will facilitate future studies investigating the role of IL-11 in fertility.