NLRP proteins are important components of inflammasomes with a major role in innate immunity. A subset of NLRP genes, with unknown functions, are expressed in oocytes and early embryos. Mutations of Nlrp5 in mice are associated with maternal-effect embryonic lethality and mutations of NLRP7 in women are associated with conception of biparental complete hydatidiform moles (biCHMs), suggesting perturbed processes of genomic imprinting. Recessive mutations on NLRP2/7 in humans are associated with reproductive disorders and appear to be induced by a demethylation of the maternal pronucleus. In this study, we find that radiation of NLRP genes occurred before the common ancestor of Afrotheria and Boreoeutheria, with the clade of oocyte-expressed genes originating before the divergence of marsupial and eutherian mammals. There have been multiple independent duplications of NLRP2 genes one of which produced the NLRP7 gene associated with biCHMs.
Duenez-Guzman, Edgar AHaig, DavidengHoward Hughes Medical Institute/Research Support, Non-U.S. Gov'tGermany2014/03/13 06:00J Mol Evol. 2014 Apr;78(3-4):194-201. doi: 10.1007/s00239-014-9614-3. Epub 2014 Mar 11.