title: Reorganisation of Hoxd regulatory landscapes during the evolution of a snake-like body plan.
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.
authors.affiliation: Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.
authors.forename: Isabel
authors.initials: I
authors.lastname: Guerreiro
authors.affiliation: Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.
authors.forename: Sandra
authors.initials: S
authors.lastname: Gitto
authors.affiliation: Instituto Gulbenkian de Ciência, Lisbon, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Novoa
authors.affiliation: Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.
authors.forename: Julien
authors.initials: J
authors.lastname: Codourey
authors.affiliation: Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.
authors.forename: Thi Hanh
authors.initials: TH
authors.lastname: Nguyen Huynh
authors.affiliation: Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.
authors.forename: Federico
authors.initials: F
authors.lastname: Gonzalez
authors.affiliation: Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.
authors.forename: Michel C
authors.initials: MC
authors.lastname: Milinkovitch
authors.affiliation: Instituto Gulbenkian de Ciência, Lisbon, Portugal.
authors.forename: Moises
authors.identifier: 0000-0002-9744-0912
authors.initials: M
authors.lastname: Mallo
authors.affiliation: Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.|School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Denis
authors.identifier: 0000-0001-9961-2960
authors.initials: D
authors.lastname: Duboule
mesh_terms: D000818:Animals; D019521:Body Patterning; D018507:Gene Expression Regulation, Developmental; D015321:Gene Rearrangement; D005801:Genes, Homeobox; D051379:Mice / Q000196:embryology*; D012911:Snakes / Q000196:embryology*
keywords: developmental biology; evolutionary biology; genomics; mouse; reptiles; snakes; squamata; stem cells