Reorganisation of Hoxd regulatory landscapes during the evolution of a snake-like body plan

Elife. 2016 Aug 1:5:e16087. doi: 10.7554/eLife.16087.

Abstract

Within land vertebrate species, snakes display extreme variations in their body plan, characterized by the absence of limbs and an elongated morphology. Such a particular interpretation of the basic vertebrate body architecture has often been associated with changes in the function or regulation of Hox genes. Here, we use an interspecies comparative approach to investigate different regulatory aspects at the snake HoxD locus. We report that, unlike in other vertebrates, snake mesoderm-specific enhancers are mostly located within the HoxD cluster itself rather than outside. In addition, despite both the absence of limbs and an altered Hoxd gene regulation in external genitalia, the limb-associated bimodal HoxD chromatin structure is maintained at the snake locus. Finally, we show that snake and mouse orthologous enhancer sequences can display distinct expression specificities. These results show that vertebrate morphological evolution likely involved extensive reorganisation at Hox loci, yet within a generally conserved regulatory framework.

Keywords: developmental biology; evolutionary biology; genomics; mouse; reptiles; snakes; squamata; stem cells.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Patterning*
  • Gene Expression Regulation, Developmental*
  • Gene Rearrangement
  • Genes, Homeobox*
  • Mice / embryology*
  • Snakes / embryology*

Grants and funding

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.