Roles of dental development and adaptation in rodent evolution.
In paleontology, many changes affecting morphology, such as tooth shape in mammals, are interpreted as ecological adaptations that reflect important selective events. Despite continuing studies, the identification of the genetic bases and key ecological drivers of specific mammalian dental morphologies remains elusive. Here we focus on the genetic and functional bases of stephanodonty, a pattern characterized by longitudinal crests on molars that arose in parallel during the diversification of murine rodents. We find that overexpression of Eda or Edar is sufficient to produce the longitudinal crests defining stephanodonty in transgenic laboratory mice. Whereas our dental microwear analyses show that stephanodonty likely represents an adaptation to highly fibrous diet, the initial and parallel appearance of stephanodonty may have been facilitated by developmental processes, without being necessarily under positive selection. This study demonstrates how combining development and function can help to evaluate adaptive scenarios in the evolution of new morphologies.
Team 'Evo-Devo of Vertebrate Dentition', Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, Université de Lyon, Université Lyon 1, CNRS, Ecole Normale Supérieure de Lyon, 32-34 avenue Tony Garnier, F-69007 Lyon, France.
Helder Gomes
HG
Rodrigues
Sabrina
S
Renaud
Cyril
C
Charles
Yann
Y
Le Poul
Floréal
F
Solé
Jean-Pierre
JP
Aguilar
Jacques
J
Michaux
Paul
P
Tafforeau
Denis
D
Headon
Jukka
J
Jernvall
Laurent
L
Viriot
D000222:Adaptation, Physiological / Q000235:genetics*; D000818:Animals; D005075:Biological Evolution; D004032:Diet; D053331:Ectodysplasins / Q000235:genetics / Q000378:metabolism; D053339:Edar Receptor / Q000235:genetics / Q000378:metabolism; D005580:Fossils; D015870:Gene Expression; D051379:Mice; D008822:Mice, Transgenic; D008963:Molar / Q000033:anatomy & histology* / Q000502:physiology; D010163:Paleontology; D012377:Rodentia / Q000033:anatomy & histology* / Q000502:physiology
D053331:Ectodysplasins; C506019:Eda protein, mouse; D053339:Edar Receptor; C506009:Edar protein, mouse