Identification and characterization of pufferfish, zebrafish, and chicken receptors for proglucagon-derived peptides

The pufferfish and zebrafish genome encodes 4 genes that are similar to receptors for proglucagon-derived peptides. 2 receptors are identified as glucagon receptors, 1 as a GIP receptor, and 1 as a GLP-2 receptor. I was unable to identify receptor genes in pufferfish and zebrafish that is most closely related to the human GLP-1 receptor. The chicken genome contains 3 receptors for proglucagon-derived peptides: glucagon, GLP-1, and the GLP-2 receptors. The tissue distribution of the chicken GLP-2 and glucagon receptors parallel the tissue distribution of their mammalian counterpart and therefore, I believe that the chicken receptors may have similar functions to their mammalian homologues. I compared the amino acid residue sequences of my predicted receptors to known receptors for proglucagon-derived peptides and propose that the pufferfish and zebrafish receptors have a broad specificity and the chicken receptors have more narrow specificity that is similar to human receptors for proglucagon-derived peptides.