Saunders Paul A, Franco Thomas, Sottas Camille, Maurice Tangui, Ganem Guila, Veyrunes Frédéric
Institut des Sciences de l'Evolution de Montpellier, Université de Montpellier, CNRS UMR 5554, IRD, EPHE, France.
INSERM U1198, Université de Montpellier, Inserm, EPHE, France.
Sci Rep. 2016 Mar 11;6:22881. doi: 10.1038/srep22881.
Most sex differences in phenotype are controlled by gonadal hormones, but recent work on laboratory strain mice that present discordant chromosomal and gonadal sex showed that sex chromosome complement can have a direct influence on the establishment of sex-specific behaviours, independently from gonads. In this study, we analyse the behaviour of a rodent with naturally occurring sex reversal: the African pygmy mouse Mus minutoides, in which all males are XY, while females are of three types: XX, XX* or XY (the asterisk represents an unknown X-linked mutation preventing masculinisation of XY embryos). XY females show typical female anatomy and, interestingly, have greater breeding performances. We investigate the link between sex chromosome complement, behaviour and reproductive success in females by analysing several behavioural features that could potentially influence their fitness: female attractiveness, aggressiveness and anxiety. Despite sex chromosome complement was not found to impact male mate preferences, it does influence some aspects of both aggressiveness and anxiety: X()Y females are more aggressive than the XX and XX*, and show lower anxiogenic response to novelty, like males. We discuss how these behavioural differences might impact the breeding performances of females, and how the sex chromosome complement could shape the differences observed.
大多数表型上的性别差异由性腺激素控制，但最近对具有不一致的染色体和性腺性别的实验室品系小鼠的研究表明，性染色体组成可独立于性腺对性别特异性行为的建立产生直接影响。在本研究中，我们分析了一种具有自然发生性反转的啮齿动物——非洲侏儒鼠（Mus minutoides）的行为：所有雄性为XY，而雌性有三种类型：XX、XX* 或 XY（星号代表未知的X连锁突变，可阻止XY胚胎雄性化）。XY雌性表现出典型的雌性解剖结构，有趣的是，它们具有更高的繁殖能力。我们通过分析几种可能影响其适应性的行为特征来研究雌性的性染色体组成、行为和繁殖成功之间的联系：雌性吸引力、攻击性和焦虑。尽管未发现性染色体组成会影响雄性的配偶偏好，但它确实会影响攻击性和焦虑的某些方面：X()Y雌性比XX和XX*雌性更具攻击性，并且对新奇事物的焦虑反应较低，与雄性相似。我们讨论了这些行为差异可能如何影响雌性的繁殖能力，以及性染色体组成如何塑造所观察到的差异。
