Adaptive horizontal transfer of a bacterial gene to an invasive insect pest of coffee
Adaptive horizontal transfer of a bacterial gene to an invasive insect pest of coffee
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DOI：
10.1073/pnas.1121190109
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发表时间：
2012-03-13
影响因子：
11.1
通讯作者：
Rose, Jocelyn K. C.
中科院分区：
文献类型：
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作者：
Acuna, Ricardo;Padilla, Beatriz E.;Rose, Jocelyn K. C.
水平基因转移（Horizontal gene transfer，HGT）是一种跨物种的非性遗传物质传递。虽然经常在原核生物中检测到，但涉及动物的HGT的例子相对罕见，并且赋予受体的任何进化优势通常是模糊的。我们从咖啡浆果蛀虫甲虫Hypothenemus hampei中鉴定出一个基因（HhMAN 1），Hypothenemus hampei是一种毁灭性的咖啡害虫，它显示了来自细菌的HGT的明确证据。HhMAN1编码甘露聚糖酶，代表了一类以前在昆虫中没有报道的糖基水解酶。重组HhMAN 1蛋白水解咖啡果半乳甘露聚糖，该种中的主要贮藏多糖和H.火腿。HhMAN1在一项广泛的H. hampei加入，表明HGT事件发生在该昆虫从西非辐射到亚洲和南美洲之前。然而，该基因在密切相关的物种H中未检测到。obscurus（热带坚果蛀虫或“假浆果蛀虫”），它不会在咖啡豆上定居。因此，HhMAN 1从细菌的HGT代表了一个可能的适应特定的生态位，并可能已被促进集约化农业实践。
Horizontal gene transfer (HGT) involves the nonsexual transmission of genetic material across species boundaries. Although often detected in prokaryotes, examples of HGT involving animals are relatively rare, and any evolutionary advantage conferred to the recipient is typically obscure. We identified a gene (HhMAN1) from the coffee berry borer beetle, Hypothenemus hampei, a devastating pest of coffee, which shows clear evidence of HGT from bacteria. HhMAN1 encodes a mannanase, representing a class of glycosyl hydrolases that has not previously been reported in insects. Recombinant HhMAN1 protein hydrolyzes coffee berry galactomannan, the major storage polysaccharide in this species and the presumed food of H. hampei. HhMAN1 was found to be widespread in a broad biogeographic survey of H. hampei accessions, indicating that the HGT event occurred before radiation of the insect from West Africa to Asia and South America. However, the gene was not detected in the closely related species H. obscurus (the tropical nut borer or "false berry borer"), which does not colonize coffee beans. Thus, HGT of HhMAN1 from bacteria represents a likely adaptation to a specific ecological niche and may have been promoted by intensive agricultural practices.