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 required for female fertility. In the absence of IL-11, decidualization is markedly 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 rat IL-11 and IL-11R alpha. RNase protection was used to demonstrate that expression of IL-11 is upregulated in the rat uterus at the initiation of implantation 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 mice, expression of IL-11 was high in the primary decidual zone at the time of the attachment reaction, whereas IL11Ra was expressed throughout primary and secondary decidua. Conservation of the temporal and spatial expression of IL-11 and IL-11R alpha in the uterus of the mouse and rat during the peri-implantation period will facilitate future studies investigating the role of IL-11 in fertility.