Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA; email:
Annu Rev Entomol. 2019 Jan 7;64:227-242. doi: 10.1146/annurev-ento-020117-043322. Epub 2018 Oct 12.
The evolutionary origins of the three major families of chemoreceptors in arthropods-the odorant receptor (OR), gustatory receptor (GR), and ionotropic receptor (IR) families-occurred at the base of the Insecta, Animalia, and Protostomia, respectively. Comparison of receptor family sizes across arthropods reveals a generally positive correlation with their widely disparate complexity of chemical ecology. Closely related species reveal the ongoing processes of gene family evolution, including gene duplication, divergence, pseudogenization, and loss, that mediate these larger patterns. Sets of paralogous receptors within species reveal positive selection on amino acids in regions likely to contribute to ligand binding and specificity. Ligands of many ORs and some GRs and IRs have been identified; however, ligand identification for many more chemoreceptors is needed, as are structures for the OR/GR superfamily, to improve our understanding of the molecular evolution of these ecologically important receptors in arthropods.
昆虫、动物和原口动物三支主要化学感受器家族（气味受体[OR]、味觉受体[GR]和离子型受体[IR]）在节肢动物中的进化起源分别发生在昆虫、动物和原口动物的基部。对不同节肢动物中受体家族大小的比较表明，与它们化学生态的广泛差异呈正相关。密切相关的物种揭示了基因家族进化的持续过程，包括基因复制、分化、假基因化和丢失，这些过程介导了这些更大的模式。物种内的同源受体集揭示了对可能有助于配体结合和特异性的氨基酸的正选择。已经鉴定出许多 OR 和一些 GR 和 IR 的配体；然而，还需要鉴定更多化学感受器的配体，也需要 OR/GR 超家族的结构，以提高我们对这些在节肢动物中具有重要生态意义的受体的分子进化的理解。
