Ribosomal RNA gene silencing in interpopulation hybrids of Tigriopus californicus: nucleolar dominance in the absence of intergenic spacer subrepeats.

ABSTRACT: A common feature of interspecific animal and plant hybrids is the uniparental silencing of ribosomal RNA gene transcription, or nucleolar dominance. A leading explanation for the genetic basis of nucleolar dominance in animal hybrids is the enhancer-imbalance model. The model proposes that limiting transcription factors are titrated by a greater number of enhancer-bearing subrepeat elements in the intergenic spacer (IGS) of the dominant cluster of genes. The importance of subrepeats for nucleolar dominance has repeatedly been supported in competition assays between Xenopus laevis and X. borealis minigene constructs injected into oocytes. However, a more general test of the importance of IGS subrepeats for nuclear dominance in vivo has not been conducted. In this report, rRNA gene expressio

SUBMITTER: Flowers JM 

PROVIDER: S-EPMC1526681 | biostudies-literature | 2006 Jul

REPOSITORIES: biostudies-literature