ZFIN ID: ZDB-PUB-160526-7
Corticotropin-releasing hormone family evolution: five ancestral genes remain in some lineages
Cardoso, J.C., Bergqvist, C.A., Felix, R.C., Larhammar, D.
Date: 2016
Source: Journal of molecular endocrinology   57(1): 73-86 (Journal)
Registered Authors: Bergqvist, Christina, Larhammar, Dan
Keywords: CRH/UCN, phylogeny, gene duplication, synteny, chromosome duplication
MeSH Terms:
  • Amino Acid Sequence
  • Animals
  • Computational Biology/methods
  • Corticotropin-Releasing Hormone/chemistry
  • Corticotropin-Releasing Hormone/classification
  • Corticotropin-Releasing Hormone/genetics*
  • Data Mining
  • Databases, Genetic
  • Evolution, Molecular*
  • Humans
  • Mammals/classification
  • Mammals/genetics
  • Multigene Family*
  • Phylogeny
  • Vertebrates/classification
  • Vertebrates/genetics
PubMed: 27220618 Full text @ J. Mol. Endocrinol.
ABSTRACT
The evolution of the peptide family consisting of corticotropin-releasing hormone (CRH) and the three urocortins (UCN1-3) has been puzzling due to uneven evolutionary rates. Distinct gene duplication scenarios have been proposed in relation to the two basal rounds of vertebrate genome doubling (2R) and the teleost fish-specific genome doublings (3R). By analyses of sequences and chromosomal regions, including many neighbouring gene families, we show here that the vertebrate progenitor had two peptide genes that served as the founders of separate subfamilies. Then 2R resulted in a total of five members: one subfamily consists of CRH1, CRH2, and UCN1. The other subfamily contains UCN2 and UCN3. All five peptide genes are present in the slowly evolving genomes of the coelacanth Latimeria chalumnae (a lobe-finned fish), the spotted gar Lepisosteus oculatus (a basal ray-finned fish), and the elephant shark Callorhinchus milii (a cartilaginous fish). The CRH2 gene has been lost independently in placental mammals and in teleost fish but is present in birds (except chicken), in the anole lizard and non-placental mammals platypus and opossum. Teleost 3R resulted in an additional surviving duplicate only for CRH1 in some teleosts including zebrafish (CRH1a and CRH1b). We have previously reported that the two vertebrate CRH/UCN receptors arose in 2R and that CRHR1 was duplicated in 3R. Thus, we can now conclude that this peptide-receptor system was quite complex in the ancestor of the jawed vertebrates with five CRH/UCN peptides and two receptors, and that CRH and CRHR1 were duplicated in the teleost fish tetraploidization.
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