Ermakova Galina V, Meyntser Irina V, Mugue Nikolai S, Lyubetsky Vassily A, Zaraisky Andrey G, Bayramov Andrey V
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
Biological Department of the Mosqvarium Center for Oceanography and Marine Biology, Moscow, Russia.
Front Cell Dev Biol. 2025 Aug 29;13:1649996. doi: 10.3389/fcell.2025.1649996. eCollection 2025.
Genomic transformations during early vertebrate evolution, including two rounds of whole-genome duplication, laid the groundwork for the emergence of novel morphological features in jawed vertebrates. Among these innovations, paired appendages represent a major evolutionary milestone, whose development and diversification enabled vertebrates to exploit diverse ecological niches in aquatic, terrestrial, and aerial environments. Here, we combined phylogenetic and local genomic synteny analyses to investigate the evolutionary history of homologs in vertebrates. Our results indicate that first appeared in jawed vertebrates, suggesting a possible link between its origin and the emergence of paired appendages. To explore this hypothesis, we examined expression in representatives of basal jawed vertebrate lineages - cartilaginous fishes (grey catshark, ) and sturgeons (sterlet, ). We further assessed the expression and functional properties of the ortholog in the African clawed frog (), a representative terrestrial vertebrate with limb morphology that markedly differs from the fins of basal gnathostomes. Together with published data, our findings support a potential role for chordin-like1 in the evolution of paired appendages. In particular, may have contributed to the development of the metapterygial element and its derivatives, which formed the structural basis for the evolution of tetrapod limbs.
早期脊椎动物进化过程中的基因组转变，包括两轮全基因组复制，为有颌脊椎动物新形态特征的出现奠定了基础。在这些创新之中，成对附肢代表了一个主要的进化里程碑，其发育和多样化使脊椎动物能够在水生、陆地和空中环境中开拓多样的生态位。在此，我们结合系统发育和局部基因组共线性分析，来研究脊椎动物中同源物的进化历史。我们的结果表明，[具体基因名称]首次出现在有颌脊椎动物中，这表明其起源与成对附肢的出现之间可能存在联系。为了探究这一假说，我们检测了基部有颌脊椎动物谱系代表——软骨鱼类（灰星鲨，[具体学名]）和鲟鱼（小体鲟，[具体学名]）中[具体基因名称]的表达。我们进一步评估了非洲爪蟾（[具体学名]）中[具体基因名称]直系同源物的表达和功能特性，非洲爪蟾是一种具有与基部有颌类动物鳍显著不同的肢体形态的代表性陆生脊椎动物。结合已发表的数据，我们的发现支持了类脊索蛋白1在成对附肢进化中的潜在作用。特别是，[具体基因名称]可能对中鳍元素及其衍生物的发育有贡献，这些衍生物构成了四足动物肢体进化的结构基础。
