ARS | Publication request: Identification and Profiling of Bovine Micrornas from Immune Related and Embryonic Tissues.

Submitted to: BARC Poster Day
Publication Type: Abstract
Publication Acceptance Date: March 8, 2006
Publication Date: April 26, 2006
Citation: Coutinho, L.L., Matukumalli, L.K., Sonstegard, T.S., Van Tassell, C.P., Gasbarre, L.C., Capuco, A.V., Smith, T.P. 2006. Identification and profiling of bovine micrornas from immune related and embryonic tissues [abstract]. 17th Annual BARC Poster Day, Beltsville, MD. No 6.

Technical Abstract: MicroRNAs are a recently discovered class of small ~22 nucleotide-long non-coding RNAs capable of controlling gene expression by inhibiting translation or targeting messenger RNA for degradation. Since there is no information regarding microRNAs in bovine, this work was designed to characterize this new class of RNA in tissues important for immune response and development. Alignment of human microRNA stem loop sequences (mir) against the bovine genome resulted in identification of 221 predicted bovine mirs. In order to validate these predictions and identify mirs we constructed and sequenced cDNA libraries made from small RNA fractions of bovine embryo, thymus, small intestine, abomasum, and mesenteric lymph nodes. This strategy resulted in identification of 129 putative mature microRNAs (miRs). Of these, 100 align to known human miRs supporting their designation as bona fide miRs. An additional seven align to the complementary arm of a known human miR, and thus are novel miRs. Interestingly, 22 that do not have matches to human mirs displayed characteristic mir secondary structures, and 11 of these show phylogenetic conservation among other vertebrate species. Further characterization based on tissue abundance resulted in identification of miRs that were preferentially expressed in embryo, small intestine or immune-related tissues. The prevalence of bta-miR-26a in all libraries and discovery of miRs from the complementary strand of known human mirs indicate that important insights into miR regulation can be gained through comparative studies between species. Since miRs are important in biological processes including adipocyte differentiation, muscle development, insulin secretion, cancer and immune response, the characterization of bovine miRs will further enhance understanding of biological processes important for animal production. Supported by USDA ARS CRIS Project No. 1265-31000-081-00D