BONILLA, A.J.*; KIMBALL, R.T.; BRAUN, E.L.; Univ. of Florida, Gainesville; Univ. of Florida, Gainesville; Univ. of Florida, Gainesville: Conservation and Molecular Evolution of 3� Untranslated Regions in Birds

A limited amount is known regarding the function of 3� untranslated regions (UTRs) of vertebrate messenger RNAs (mRNAs), though roles in the regulation of both mRNA stability and the rate at which the encoded proteins are translated have been demonstrated for specific mRNAs. Phylogenetic shadowing (the use of comparative datasets to examine rates of sequence evolution at specific sites) is used to identify functionally important regions in sequences. We have applied this technique to the 3� UTRs of five genes spread across the avian genome from 25 species of galliform birds (members of the order containing chickens, pheasants, quail and their allies) and a smaller number of non-galliform taxa. This sampling allows us to examine sequence conservation among a closely related set of species, as well as across a set of more divergent species. To perform phylogenetic shadowing, we examined patterns of molecular evolution (base composition, evolutionary rate, substitution patterns) between the 3� UTR�s and a related set of introns and exons from the same loci. We found among-sites rate variation and evidence for regions subject to purifying selection. The UTRs differed from each other in a number of molecular evolutionary patterns These results and additional detailed analyses will be presented.