| dc.description.abstract | The TTG1-regulatory gene network regulates the development of all epidermal cell fates in
Arabidopsis thaliana. Four members of the TTG1 complex, the serially duplicated R2R3-MYB PRODUCTION
OF ANTHOCYANIN PIGMENT (PAP) genes, have previously been implicated in regulating the
late stages of anthocyanin bionsynthesis in Arabidopsis thaliana. To study the effects of gene
duplication, we sought to determine the extent of variation in each PAP gene compared to a single
copy gene of the TTG1 network, WEREWOLF, using 48 naturally occurring A. thaliana accessions. It
appears that the predominantly expressed PAP1 gene demonstrates a biallelic pattern, consistent
with other A. thaliana genes. All four genes fall below the average nucleotide diversity levels
observed across A. thaliana; however, WEREWOLF demonstrates almost complete sequence conservation
across the 48 accessions used in this study. We attempted to determine the relative ages of the
four PAP genes, though this does not appear to correlate with accumulation of genetic variation. To
investigate the genetic architecture of anthocyanin accumulation in A. thaliana, we performed an
heritability and quantitative trait loci mapping analysis using a recombinant inbred line
population derived from 19 natural A. thaliana accessions. While QTL were mapped for anthocyanin
accumulation near several of the PAP genes, we observed a number of loci with no obvious candidate
genes, providing novel insights into the genetic architecture of anthocyanin accumulation in A.
thaliana. This work contributes to a greater understanding of the roles of regulatory genes in
biosynthesis and the molecular basis of regulation as well as the effects of gene duplication on
nucleotide variation in the resulting genes. | en |
