Epigenetic allelic states of a maize transcriptional regulatory locus exhibit overdominant gene action

  • Hollick J
  • Chandler V
  • 29

    Readers

    Mendeley users who have this article in their library.
  • 53

    Citations

    Citations of this article.

Abstract

Using alleles of the maize purple plant locus (pl), which encodes a transcriptional regulator of anthocyanin pigment synthesis, we describe a case of single-locus heterosis, or overdominance, where the heterozygote displays a phenotype that is greater than either homozygote. The Pl-Rhoades (Pl-Rh) allele is subject to epigenetic changes in gene expression, resulting in quantitatively distinct expression states. Allelic states with low-expression levels, designated Pl'-mahogany (Pl'-mah), are dominant to the high-expression state of Pl-Rh. Pl'-mah states retain low-expression levels in subsequent generations when homozygous or heterozygous with Pl-Rh. However, Pl'-mah alleles frequently exhibit higher expression levels when heterozygous with other pl alleles; illustrating an overdominant allelic relationship. Higher expression levels are also observed when Pl'-mah is hemizygous. These results suggest that persistent allelic interactions between Pl'-mah and Pl-Rh are required to maintain the low-expression state and that other pl alleles are missing sequences required for this interaction. The Pl-Rh state can be sexually transmitted from Pl'-mah/pl heterozygotes, but not from Pl'-mah hemizygotes, suggesting that fixation of the high-expression state may involve synapsis. The existence of such allele-dependent regulatory mechanisms implicates a novel importance of allele polymorphisms in the genesis and maintenance of genetic variation.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Jay B. Hollick

  • Vicki L. Chandler

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free