Cardoso, João CRVieira, Florbela A.Clark, M. S.Power, Deborah2014-10-242014-10-242006Cardoso JCR, Vieira F, Clark MS and Power DM (2006) Putative ancestral receptor genes of vertebrate family 2 GPCR in the invertebrate genome of the nematode Caenorhabditis elegans. Journal of Experimental Zoology Part A-Comparative Experimental Biology 305A (2): 115-1151548-8969AUT: DPO00386http://hdl.handle.net/10400.1/5470Three putative ancestral genes for the family 2 of GPCRs were identified in the invertebrate genome of the nematode Caenorhabditis elegans (C. elegans). The nematode clones namely CB13B9.4, ZK643.3 and C18B12.2 are localised on chromosomes III (CB13B9.4, ZK643.3) and X (C18B12.2) and were identified by searching the nematode genome database with the amino acid sequences of the vertebrate family 2 receptor genes. In human and in the teleost Takifugu rubripes genomes, 15 and 21 members of the family 2 GPCRs have been identified, respectively. Linkage mapping analysis revealed that the gene environment of family 2 GPCRs is highly conserved between human and Takifugu genomes and some conservation also occurs with C. elegans chromosome III and X regions containing the putative family 2 GPCRs. Sequence comparative analysis revealed that the putative C. elegans receptors contained seven transmembrane (TM) domains and long N-terminal regions with conserved cysteine residues typical of the family 2 GPCR members. Phylogenetic analysis carried out with the TM domains of all vertebrate, chordate (Ciona) and insect (fruit fly) family 2 receptor members has shown that the nematode receptors identified tend to group with the clade containing the CRF and Calcitonin/CGRP family 2 GPCRs.engjournal article