Ginot Samuel, Claude Julien, Perez Julie, Veyrunes Frederic
Institut des Sciences de l'Evolution de Montpellier, Universite de Montpellier, CNRS, IRD, Cc 064; Place Eugene Bataillon, Montpellier Cedex 5 34095, France
Institut des Sciences de l'Evolution de Montpellier, Universite de Montpellier, CNRS, IRD, Cc 064; Place Eugene Bataillon, Montpellier Cedex 5 34095, France.
J Exp Biol. 2017 Jun 1;220(Pt 11):1947-1951. doi: 10.1242/jeb.157552.
Differences in biological performance, at both intra- and inter-specific levels, have often been linked to morphology but seldom to behavioural or genotypic effects. We tested performance at the intraspecific level by measuring bite force in the African pygmy mouse, This species displays an unusual sex determination system, with sex-reversed, XY females carrying a feminizing X chromosome. XY females cannot be differentiated from XX females based on external or gonadal morphology; however, they are known to be more aggressive. We found that bite force was higher in XY females than in other females and males. We then performed geometric morphometric analyses on their skulls and mandibles and found that the higher performance of XY females was mainly explained by a greater overall skull size. The effects of the X chromosome thus go beyond feminization, and extend to whole-organism performance and morphology. Our results also suggest limited effects of behaviour on bite force.
在种内和种间水平上，生物性能的差异通常与形态学有关，但很少与行为或基因型效应有关。我们通过测量非洲侏儒小鼠的咬合力来测试种内水平的性能。该物种表现出一种不寻常的性别决定系统，具有性别反转的XY雌性，携带一条具有雌性化作用的X染色体。基于外部或性腺形态，无法将XY雌性与XX雌性区分开来；然而，已知它们更具攻击性。我们发现，XY雌性的咬合力高于其他雌性和雄性。然后，我们对它们的头骨和下颌进行了几何形态测量分析，发现XY雌性较高的性能主要是由更大的整体头骨尺寸所解释。因此，X染色体的影响不仅限于雌性化，还扩展到整个生物体的性能和形态。我们的结果还表明行为对咬合力的影响有限。
