Structure of the mouse calcitonin/calcitonin gene-related peptide alpha and beta genes

We report the cloning, genomic organization and sequence of the mouse alpha -CALC and beta -CALC genes. The two genes share extensive sequence homology. The transcription units of both genes contain 6 exons. Transcripts of the alpha -CALC gene were found to alternatively include exon 4 or exons 5 and 6. For the beta -CALC gene exon 4 was not detected in transcripts derived from this gene. The predicted mouse alpha -CGRP was found to be identical to rat alpha -CGRP, however, beta -CGRP predicted amino acid sequences revealed three amino acid differences suggesting these residues are not critical to CGRP function.