The impact of polyploidy on yeast transcription factor evolution

Devin Scannell(1), Mario Fares(2), Ken Wolfe(1). (1) Genetics Department, Trinity College Dublin, College Green, Dublin, D2, Ireland; (2) Biology Department, N.U.I. Maynooth, Maynooth , Co. Kildare, Ireland.

We developed tools to identify sets of orthologous genes, and used them to find groups of (co-) orthologous transcription factors from ten currently available yeast genome sequences. These yeast orthology groups (YOGs) were analyzed using likelihood and parsimony based bioinformatics methods, to determine the selective constraints operating in different lineages. In particular we test the hypothesis that a massive and sudden increase in gene complement, such as occurs in a whole genome duplication, should be accompanied by complementary evolutionary changes in genes that encode regulators of gene expression. Prior evidence for this comes from S. cerevisiae where many gene pairs formed by polyploidy (ohnologs) exist as aerobic and hypoxic pairs. We used a high quality set of cis-regulatory elements (assembled by Kellis et al. based on phylogenetic footprinting) to find cis-elements that are over-represented in duplicated genes formed by polyploidy. The association between these cis-elements and particular transcription factors is investigated.

Program Nr. 517A from 2004 Yeast meeting

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