Vascularization underlies differences in sexually selected skin coloration in a wild primate
Vascularization underlies differences in sexually selected skin coloration in a wild primate
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DOI：
10.1111/mec.17026
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发表时间：
2023-05-24
影响因子：
4.9
通讯作者：
Snyder-Mackler, Noah
中科院分区：
文献类型：
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作者：
DeLacey, Patricia M.;Sen, Sharmi;Snyder-Mackler, Noah
雄性生殖竞争可以选择依赖于条件的显着特征，这些特征表明战斗能力的某些方面并有助于评估潜在竞争对手。然而，将信号与雄性当前状况联系起来的潜在机制很难在野生种群中进行研究，通常需要侵入性实验操作。在这里，我们使用数码照片和胸部皮肤样本来研究野生灵长类动物雄性竞争中使用的视觉信号的机制，即狒狒（Theropithecus gelada）的红色胸部斑块。我们分析了在自然条件下（n = 144）和麻醉条件下（n = 38）收集的照片，以了解男性和女性胸部发红的变异性，并使用胸部皮肤活检（n = 38）来探索基因表达的性别差异。雄性和雌性狒狒表现出相似的平均红色度，但在自然条件下，雄性狒狒表现出更广泛的个体内红色度范围。这些性别差异也反映在分子水平上，10.5%的基因在表达上表现出显着的性别差异。亚成年雄性表现出介于成年雄性和雌性之间的中间基因表达模式，这表明了胸部红色斑块发育的潜在机制。我们发现，在男性中表达较高的基因与血管发育和维持有关，但与雄激素或雌激素活性无关。总之，我们的结果表明，雄性狒狒发红的变异性是由胸部皮肤血管分支增加所驱动的，这提供了雄性胸部发红与当前状况之间的潜在联系，因为裸露皮肤的血液循环增加可能导致狒狒在寒冷的高海拔环境中热量损失。
Male reproductive competition can select for condition-dependent, conspicuous traits that signal some aspect of fighting ability and facilitate assessment of potential rivals. However, the underlying mechanisms that link the signal to a male's current condition are difficult to investigate in wild populations, often requiring invasive experimental manipulation. Here, we use digital photographs and chest skin samples to investigate the mechanisms of a visual signal used in male competition in a wild primate, the red chest patch in geladas (Theropithecus gelada). We analysed photographs collected during natural (n = 144) and anaesthetized conditions (n = 38) to understand variability in male and female chest redness, and we used chest skin biopsies (n = 38) to explore sex differences in gene expression. Male and female geladas showed similar average redness, but males exhibited a wider within-individual range in redness under natural conditions. These sex differences were also reflected at the molecular level, with 10.5% of genes exhibiting significant sex differences in expression. Subadult males exhibited intermediate gene expression patterns between adult males and females, pointing to mechanisms underlying the development of the red chest patch. We found that genes more highly expressed in males were associated with blood vessel development and maintenance but not with androgen or oestrogen activity. Together, our results suggest male gelada redness variability is driven by increased blood vessel branching in the chest skin, providing a potential link between male chest redness and current condition as increased blood circulation to exposed skin could lead to heat loss in the cold, high-altitude environment of geladas.