Submitted to: Joint Abstracts of the American Dairy Science and Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 2/20/2005
Publication Date: 7/1/2005
Citation: Connor, E.E., Laiakis, E.C., Fernandes, V.M., Williams, J.L., Capuco, A.V. 2005. Sequencing, chromosomal mapping and expression of the bovine deiodinase type II (DI02)and deiodinase type III (DI03) genes [abstract]. J. Dairy Science. 83(1):167-168.
Technical Abstract: Thyroid hormones are critical for normal mammalian development and metabolism and their activity is regulated in a highly complex, tissue-specific manner by three isoforms of deiodinases. We determined the full-length bovine type II deiodinase (DIO2) and type III deiodinase (DIO3) mRNA sequences and characterized expression levels of each of the three deiodinase isoform transcripts in several bovine tissues. Further, bovine DIO2 and DIO3 were positioned on chromosomes 10 and 21, respectively, by radiation hybrid mapping. Sequencing of bovine DIO2 and DIO3 cDNAs revealed a high degree of predicted amino acid sequence identity with their orthologs in other mammalian species and demonstrated the conservation of selenocysteine residues within the catalytic domains of both bovine proteins. In addition, three putative single nucleotide polymorphisms and one insertion/deletion were identified in the bovine DIO2 transcript. Expression patterns of the three deiodinase isoforms in bovine tissues were similar for deiodinase type I (DIO1) and type 2 (DIO2) to those observed in other species. Expression level of DIO3 transcripts was greatest in bovine mammary gland and kidney, although expression was detected in all tissues sampled. Results of this work will aid in the study of deiodinase gene expression and thyroid hormone regulation in cattle.