Potential role of interleukin-1 at the peri-ovulation stage in a species of placental viviparous reptile, the three-toed skink, Chalcides chalcides (Squamata: Scincidae)

We recently showed that interleukin-1 (IL-1) is secreted by the placenta of a species of squamate reptile, the three-toed skink, Chalcides chalcides. In this study, we used immunohistochemical techniques to investigate the expression of IL-1 (in the two isoforms, IL-1alpha and IL-1beta) and its specific membrane receptor IL-1 RtI in uterine oviduct during the peri-implantation period. We found that both IL-1 and its receptor were expressed in uterine tissues before and after ovulation (in the pre-ovulatory stage, even before the yolk had formed in the ovary). However, while IL-1alpha was mostly localized in the uterine mesenchyme tissue, IL-1beta and IL-1RtI were present in the uterine epithelium. Our data provide a further comparison between the reproduction of mammals and squamate reptiles.