Genetic regulation of amphioxus somitogenesis informs the evolution of the vertebrate head mesoderm.
Nat Ecol Evol
; 3(8): 1233-1240, 2019 08.
Article
em En
| MEDLINE
| ID: mdl-31263232
ABSTRACT
The evolution of vertebrates from an ancestral chordate was accompanied by the acquisition of a predatory lifestyle closely associated to the origin of a novel anterior structure, the highly specialized head. While the vertebrate head mesoderm is unsegmented, the paraxial mesoderm of the earliest divergent chordate clade, the cephalochordates (amphioxus), is fully segmented in somites. We have previously shown that fibroblast growth factor signalling controls the formation of the most anterior somites in amphioxus; therefore, unravelling the fibroblast growth factor signalling downstream effectors is of crucial importance to shed light on the evolutionary origin of vertebrate head muscles. By using a comparative RNA sequencing approach and genetic functional analyses, we show that several transcription factors, such as Six1/2, Pax3/7 and Zic, act in combination to ensure the formation of three different somite populations. Interestingly, these proteins are orthologous to key regulators of trunk, and not head, muscle formation in vertebrates. Contrary to prevailing thinking, our results suggest that the vertebrate head mesoderm is of visceral and not paraxial origin and support a multistep evolutionary scenario for the appearance of the unsegmented mesoderm of the vertebrates new 'head'.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Anfioxos
Limite:
Animals
Idioma:
En
Revista:
Nat Ecol Evol
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
França