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Increased chromatin accessibility promotes the evolution of a transcriptional silencer in Drosophila .

Liucong LingBettina MühlingRita JaenichenNicolas Gompel
Published in: Science advances (2023)
The loss of discrete morphological traits, the most common evolutionary transition, is typically driven by changes in developmental gene expression. Mutations accumulating in regulatory elements of these genes can disrupt DNA binding sites for transcription factors patterning their spatial expression, or delete entire enhancers. Regulatory elements, however, may be silenced through changes in chromatin accessibility or the emergence of repressive elements. Here, we show that increased chromatin accessibility at the gene yellow , combined with the gain of a repressor site, underlies the loss of a wing spot pigmentation pattern in a Drosophila species. The gain of accessibility of this repressive element is regulated by E93, a transcription factor governing the progress of metamorphosis. This convoluted evolutionary scenario contrasts with the parsimonious mutational paths generally envisioned and often documented for morphological losses. It illustrates how evolutionary changes in chromatin accessibility may directly contribute to morphological diversification.
Keyphrases
  • transcription factor
  • genome wide
  • genome wide identification
  • gene expression
  • dna methylation
  • dna binding
  • copy number
  • poor prognosis
  • dna damage
  • single molecule
  • binding protein