Department of Anatomy, Animal Production and Clinical Veterinary Sciences, Faculty of Veterinary, University of Santiago de Compostela, Av. Carballo Calero s/n, 27002 Lugo, Spain.
College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju 63243, Republic of Korea.
Int J Mol Sci. 2024 Jul 2;25(13):7291. doi: 10.3390/ijms25137291.
The mammalian vomeronasal system enables the perception of chemical signals crucial for social communication via the receptor families V1R and V2R. These receptors are linked with the G-protein subunits, Gαi2 and Gαo, respectively. Exploring the evolutionary pathways of V1Rs and V2Rs across mammalian species remains a significant challenge, particularly when comparing genomic data with emerging immunohistochemical evidence. Recent studies have revealed the expression of Gαo in the vomeronasal neuroepithelium of wild canids, including wolves and foxes, contradicting predictions based on current genomic annotations. Our study provides detailed immunohistochemical evidence, mapping the expression of V2R receptors in the vomeronasal sensory epithelium, focusing particularly on wild canids, specifically wolves and foxes. An additional objective involves contrasting these findings with those from domestic species like dogs to highlight the evolutionary impacts of domestication on sensory systems. The employment of a specific antibody raised against the mouse V2R2, a member of the C-family of vomeronasal receptors, V2Rs, has confirmed the presence of V2R2-immunoreactivity (V2R2-ir) in the fox and wolf, but it has revealed the lack of expression in the dog. This may reflect the impact of domestication on the regression of the VNS in this species, in contrast to their wild counterparts, and it underscores the effects of artificial selection on sensory functions. Thus, these findings suggest a more refined chemical detection capability in wild species.
哺乳动物的犁鼻器系统通过 V1R 和 V2R 受体家族感知对社会交流至关重要的化学信号。这些受体分别与 G 蛋白亚基 Gαi2 和 Gαo 相连。探索 V1R 和 V2R 在哺乳动物物种中的进化途径仍然是一个重大挑战，特别是在将基因组数据与新兴免疫组织化学证据进行比较时。最近的研究表明，Gαo 在野生犬科动物（包括狼和狐狸）的犁鼻神经上皮中表达，这与基于当前基因组注释的预测相矛盾。我们的研究提供了详细的免疫组织化学证据，描绘了 V2R 受体在犁鼻感觉上皮中的表达，特别关注野生犬科动物，即狼和狐狸。另一个目标是将这些发现与犬等家养物种进行对比，以突出驯化对感觉系统的进化影响。使用针对老鼠 V2R2 的特异性抗体（C 家族犁鼻受体 V2R 的成员）证实了狐狸和狼中存在 V2R2 免疫反应性（V2R2-ir），但在狗中未检测到表达。这可能反映了驯化对该物种 VNS 退化的影响，与野生对应物形成对比，并且强调了人工选择对感觉功能的影响。因此，这些发现表明野生物种具有更精细的化学检测能力。
