The insect odorant receptors (ORs) are amongst the largest gene families in insect genomes and the primary means by which insects recognize volatile compounds. The evolution of ORs is thus instrumental in explaining the chemical ecology of insects and as a model of evolutionary biology. However, although ORs have been described from numerous insect species, their analysis within and amongst the insect orders has been hindered by a combination of limited genomic information and a tendency of the OR family toward rapid divergence, gain, and loss. We addressed these issues in the insect order Coleoptera through a targeted genomic annotation effort that included 1181 ORs from one species of the sister order Strepsiptera and 10 species representing the four coleopteran suborders. The numbers of ORs in each species varied from hundreds to fewer than 10, but coleopteran ORs could nevertheless be represented within a scheme of nine monophyletic subfamilies. We observed many radiations and losses of genes amongst OR subfamilies, and the diversity of ORs appeared to parallel the host breadth of the study species. However, some small lineages of ORs persisted amongst many coleopteran families, suggesting receptors of key function that underlie the olfactory ecology of beetles.

中文翻译：

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甲虫（鞘翅目）中气味受体的多样性和进化。

昆虫气味受体（OR）是昆虫基因组中最大的基因家族之一，也是昆虫识别挥发性化合物的主要手段。因此，OR的进化有助于解释昆虫的化学生态，并作为进化生物学的模型。然而，尽管已经从许多昆虫物种中描述了OR，但是由于有限的基因组信息和OR家族趋于快速发散，增加和损失的趋势的结合，阻碍了它们在昆虫内部和内部的分析。我们通过有针对性的基因组注释工作解决了昆虫目鞘翅目中的这些问题，其中包括来自姊妹目Strepsiptera的一种的1181个OR和代表四个鞘翅目亚目的10个种。每个物种的OR数量从数百种到少于10种，但是鞘翅目ORs仍然可以在9个单系亚科的方案中代表。我们观察到OR亚科之间存在许多辐射和基因丢失，并且OR的多样性似乎与研究物种的宿主宽度平行。但是，在许多鞘翅目家族中仍然存在一些小的OR谱系，这表明甲虫的嗅觉生态基础中的关键功能受体。