Species differences in hormonally mediated gene expression underlie the evolutionary loss of sexually dimorphic coloration in Sceloporus lizards
Species differences in hormonally mediated gene expression underlie the evolutionary loss of sexually dimorphic coloration in Sceloporus lizards
复制标题
激素介导的基因表达的物种差异是剑孔蜥蜴两性二态性颜色进化丧失的基础
DOI：
10.1093/jhered/esad046
复制
发表时间：
2023
影响因子：
3.1
通讯作者：
Bronikowski, ed., Anne
中科院分区：
文献类型：
--
作者：
Robinson, Christopher D.;Hale, Matthew D.;Wittman, Tyler N.;Cox, Christian L.;John-Alder, Henry B.;Cox, Robert M.;Bronikowski, ed., Anne
表型性别二态性通常涉及潜在基因的性别偏向表达的激素调节。然而，目前尚不清楚激素介导的性二态性的进化是否通过上游组织对激素信号敏感性的变化、下游靶基因反应性的变化或两者兼而有之。在这里，我们使用比较转录组学来探索两种表现出不同性二色性模式的椎孔蜥蜴的这些可能性。性二态性S.波状体因对睾酮的反应而产生蓝色和黑色的腹侧颜色，但性行为单一。 virgatus 则不然，尽管循环睾酮水平表现出相似的性别差异。我们对每个物种的幼体进行睾酮植入，并使用 RNAseq 来量化腹侧皮肤的基因表达。 S 中对睾酮的转录组范围内的反应更强。波状藻比 inS. virgatus，表明组织对这种激素信号的敏感性存在差异。雄激素代谢和性激素结合球蛋白基因表达的物种差异与这一观点一致，但雄性激素受体基因的表达在S. virgatus，使这种解释复杂化。在雄激素信号下游，我们发现与黑色素合成相关的基因的激素反应性存在明显的物种差异，这些基因被睾酮 inS 上调。 undulatus，但不是 inS。维加图斯。总的来说，我们的结果表明黑色素合成途径的激素调节有助于S.性别二态性的发展。 undulatus，并且这些基因的激素反应性发生变化。 virgatus 导致腹侧颜色的进化丧失。
Phenotypic sexual dimorphism often involves the hormonal regulation of sex-biased expression for underlying genes. However, it is generally unknown whether the evolution of hormonally mediated sexual dimorphism occurs through upstream changes in tissue sensitivity to hormone signals, downstream changes in responsiveness of target genes, or both. Here, we use comparative transcriptomics to explore these possibilities in 2 species ofSceloporuslizards exhibiting different patterns of sexual dichromatism. Sexually dimorphicS. undulatusdevelops blue and black ventral coloration in response to testosterone, while sexually monomorphicS. virgatusdoes not, despite exhibiting similar sex differences in circulating testosterone levels. We administered testosterone implants to juveniles of each species and used RNAseq to quantify gene expression in ventral skin. Transcriptome-wide responses to testosterone were stronger inS. undulatusthan inS. virgatus, suggesting species differences in tissue sensitivity to this hormone signal. Species differences in the expression of genes for androgen metabolism and sex hormone-binding globulin were consistent with this idea, but expression of the androgen receptor gene was higher inS. virgatus, complicating this interpretation. Downstream of androgen signaling, we found clear species differences in hormonal responsiveness of genes related to melanin synthesis, which were upregulated by testosterone inS. undulatus, but not inS. virgatus. Collectively, our results indicate that hormonal regulation of melanin synthesis pathways contributes to the development of sexual dimorphism inS. undulatus, and that changes in the hormonal responsiveness of these genes inS. virgatuscontribute to the evolutionary loss of ventral coloration.