Submitted to: Animal Genetics
Publication Type: Research notes
Publication Acceptance Date: 1/20/2003
Publication Date: 1/20/2003
Citation: CONNOR, E.E., SONSTEGARD, T.S., KAHL, S., BENNETT, G.L., SNELLING, W.M. THE BOVINE TYPE I 5'-DEIODINASE (DIO1) GENE MAPS TO CHROMOSOME 3. ANIMAL GENETICS. vol. 34, pp. 232-240, 2003. Interpretive Summary: The thyroid hormones play an important role in animal metabolism, growth and development of the nervous and skeletal systems. Thyroxine is converted in the liver to an active form, T3 by the enzyme type I 5¿-deiodinase (DIO1). In the present study, a genetic marker was developed and used to map the DIO1 gene to bovine chromosome 3. This region of chromosome3 has been associated with the incidence of mastitis in dairy cattle and protein percentage of milk. Because T3 functions in many aspects of animal metabolism, it is a positional candidate gene contributing to these traits.
Technical Abstract: The thyroid hormones function in regulation of vertebrate metabolism, growth, skeletal maturation, and development of the nervous system. Conversion of thyroxine to the metabolically active form triiodothyronine (T3) occurs primarily in the liver by type I 5'-deiodinase (DIO1). A primer set was designed to amplify putative intron 2 of the bovine DIO1 gene. Four single nucleotide polymorphisms were detected by sequence analysis of PCR amplicons in sires of the U.S. Meat Animal Research Center cattle reference population. The bovine DIO1 was mapped by two-point analysis to chromosome 3 (BTA3; http://www.marc.usda.gov/genome/) nearest the marker BM7225 (LOD = 14.94; recombination fraction = 0.03). The assignment of DIO1 to BTA3 extends the current region of conserved synteny by approximately 16.4 Mb on the cattle-human comparative map. Quantitative trait loci associated with clinical mastitis in dairy cattle and milk protein percentage have been identified in this region of BTA3. Due to the importance of T3 in milk synthesis and energy metabolism, DIO1 is a positional candidate gene contributing to these traits.