Many animals rely heavily on olfaction to navigate their environment. Among rodents, olfaction is crucial for a wide range of social behaviors. The vomeronasal olfactory system in particular plays an important role in mediating social communication, including the detection of pheromones and recognition signals. In this study we examine patterns of vomeronasal type-1 receptor (V1R) evolution in the house mouse and related species within the genus Mus. We report the extent of gene repertoire turnover and conservation among species and clades, as well as the prevalence of positive selection on gene sequences across the V1R tree. By exploring the evolution of these receptors, we provide insight into the functional roles of receptor subtypes as well as the dynamics of gene family evolution. We generated transcriptomes from the vomeronasal organs of 5 Mus species, and produced high quality V1R repertoires for each species. We find that V1R clades in the house mouse and relatives exhibit distinct evolutionary trajectories. We identify putative species-specific gene expansions, including a large clade D expansion in the house mouse. While gene gains are abundant, we detect very few gene losses. We describe a novel V1R clade and highlight candidate receptors for future study. We find evidence for distinct evolutionary processes across different clades, from largescale turnover to highly conserved repertoires. Patterns of positive selection are similarly variable, as some clades exhibit abundant positive selection while others display high gene sequence conservation. Based on clade-level evolutionary patterns, we identify receptor families that are strong candidates for detecting social signals and predator cues. Our results reveal clades with receptors detecting female reproductive status are among the most conserved across species, suggesting an important role in V1R chemosensation. Analysis of clade-level evolution is critical for understanding species’ chemosensory adaptations. This study provides clear evidence that V1R clades are characterized by distinct evolutionary trajectories. As receptor evolution is shaped by ligand identity, these results provide a framework for examining the functional roles of receptors.

中文翻译：

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V1R进化枝在小鼠物种上的独特进化轨迹。

许多动物都严重依赖嗅觉来引导环境。在啮齿动物中，嗅觉对于广泛的社会行为至关重要。犁鼻嗅觉系统尤其在介导社交沟通（包括信息素和识别信号的检测）中起着重要作用。在这项研究中，我们研究了室内鼠和Mus属中相关物种的犁鼻型1受体（V1R）进化模式。我们报告了物种和进化枝之间的基因库更新和保护的程度，以及在整个V1R树上对基因序列进行阳性选择的普遍性。通过探索这些受体的进化，我们提供了对受体亚型的功能作用以及基因家族进化动力学的见解。我们从5个Mus物种的犁鼻器中产生了转录组，并为每个物种产生了高质量的V1R谱。我们发现家鼠和亲戚中的V1R进化枝表现出不同的进化轨迹。我们确定推定的物种特异性基因扩展，包括家鼠中的大进化枝D扩展。尽管基因增益丰富，但我们检测到的基因丢失却很少。我们描述了一个新颖的V1R进化枝，并突出了供将来研究的候选受体。我们发现证据表明，从大规模营业额到高度保守的曲目，跨不同进化枝的独特进化过程。正向选择的模式也类似，因为某些进化枝显示出丰富的正向选择，而其他进化枝则表现出较高的基因序列保守性。根据进化枝级别的进化模式，我们确定受体家族是检测社交信号和捕食者线索的强有力候选者。我们的结果表明，具有检测女性生殖状态的受体的进化枝是跨物种中最保守的进化枝，表明在V1R化学传感中具有重要作用。进化枝级进化的分析对于理解物种的化学适应性至关重要。这项研究提供了明确的证据，表明V1R进化枝具有独特的进化轨迹。由于受体的进化受配体同一性的影响，因此这些结果为检查受体的功能作用提供了框架。提示在V1R化学传感中的重要作用。进化枝级进化的分析对于理解物种的化学适应性至关重要。这项研究提供了明确的证据，表明V1R进化枝具有独特的进化轨迹。由于受体的进化受配体同一性的影响，因此这些结果为检查受体的功能作用提供了框架。提示在V1R化学传感中的重要作用。进化枝级进化的分析对于理解物种的化学适应性至关重要。这项研究提供了明确的证据，表明V1R进化枝具有独特的进化轨迹。由于受体的进化受配体同一性的影响，因此这些结果为检查受体的功能作用提供了框架。