Submitted to: Genbank
Publication Type: Abstract Only
Publication Acceptance Date: September 15, 2005
Publication Date: September 28, 2005
Citation: Richards, M.P., Poch, S.M., McMurtry, J.P. 2005. Gallus gallus preproglucagon (GCG) gene, complete cds, alternatively spliced [abstract]. GenBank Accession No. DQ185929.
The proglucagon gene in mammals produces a single identical mRNA transcript in a variety of tissues such as pancreas, intestine and brain. This transcript encodes glucagon and two glucagon-like peptide hormones (GLP-1 and GLP-2). Collectively, these peptide hormones play important roles in regulating carbohydrate, lipid and amino acid metabolism. In addition, the GLPs have specific effects on pancreatic hormone secretion, intestinal growth and function, and the control of appetite. In order to study the role of glucagon, GLP-1 and GLP-2 in poultry, it is necessary to understand the structure of the gene that encodes these important metabolic hormones. Therefore, the objective of this work was to identify and sequence the proglucagon gene in the domestic chicken (Gallus gallus). The proglucagon gene was isolated, sequenced and characterized from chicken genomic DNA using a primer-directed polymerase chain reaction (PCR) molecular cloning strategy. Direct bidirectional sequencing of overlapping PCR-generated DNA fragments identified and confirmed a total of 12,876 contiguous bases that included two putative promoter regions as well as complete coding regions and the 5'- and 3'-untranslated regions corresponding to four distinct mRNA transcripts. The chicken proglucagon gene was found to consist of 9 exons and 7 introns and to be present on chromosome 7. We also determined that four different mRNA transcripts were produced from the chicken proglucagon gene by a combination of alternative splicing and alternate promoter usage that resulted in the formation of unique 3’- and 5’-ends. This sequence data will be useful in studying the structure, expression and function of avian proglucagon genes, and in determining the roles of glucagon, GLP-1 and GLP-2 in the regulation of appetite and nutrient metabolism in commercial poultry species.