The NR1L subfamily growslarger. Gene annotation andevolutionary analyses of aunique group of nuclearreceptors in branchiopoda. Crustacea allotriocarida

Resumen

Nuclear receptors (NR) are transcription factors (TF) involved in a wide range of diverse biological processes, from development and reproduction to metabolism. Currently, there are eightNRs subfamilies described based on the similarity of their highly conserved DNA binding domain (DBD) and ligand binding domain (LBD). Apparently exclusive of arthropods, the NR1Lgroup has been recently established within the NR1 subfamily to include three NRs (HR97a,HR97b and HR97g) first characterized as hormone receptor 97 on the crustacean genus Daphnia. In this study, we identify and annotate HR97 orthologs within several Branchiopoda speciesusing in silico methods. Our results suggest that HR97 genes are absent in Anostraca, but present in Anomopoda, Spinicaudata and Notostraca. Therefore, the origin of this NR group can betraced back over 300 Mya, before the split between Notostraca and other branchiopods. Interestingly, HR97a and HR97b seem to have suffered several duplication events, passing from being asingle-copy gene in Notostraca to showing more than one copy in Diplostraca. The methodologydeveloped in this study opens a new discovery path to identify gene orthologs and characterizetheir evolution across Pancrustacea.