Symbiotic bacteria of worldwide natural populations of the Mediterranean fruit fly, Ceratitis capitata

The Mediterranean fruit fly, Ceratitis capitata, is a cosmopolitan agricultural pest of worldwide economic importance and a model for the development of the Sterile Insect Technique (SIT) for fruit flies of the Tephritidae family (Diptera). SIT relies on the effective mating of laboratory-reared strains and natural populations, and therefore requires an efficient mass-rearing system that will allow for the production of high-quality males. Adaptation of wild flies to an artificial laboratory environment can be accompanied by negative effects on several life history traits through changes in their genetic diversity and symbiotic bacterial communities. Such changes may lead to reduced biological quality and mating competitiveness in respect to the wild populations. We analyzed the gut symbiotic communities of 265 individuals (adults) from 11 natural medfly populations of worldwide distribution, including Europe, Africa, Australia, and the Americas using the 16S rRNA gene-based amplicon sequencing approach (V3-V4 region, 460 bp). Alpha and beta diversity of bacterial communities pointed to an overall reduced symbiotic diversity and the influence of the geographic location on the bacterial profile.

地中海实蝇（Ceratitis capitata）是一类具有全球经济重要性的广布性农业害虫，同时也是双翅目（Diptera）实蝇科（Tephritidae）昆虫不育技术研发的模式物种。昆虫不育技术（Sterile Insect Technique, SIT）依赖实验室饲养种群与自然种群的有效交配，因此需要一套高效的大规模饲养体系，以产出高质量的雄性个体。野生实蝇适应人工实验室环境的过程中，其遗传多样性与共生细菌群落的改变可能对多项生活史性状产生负面影响，此类变化或导致相较于野生种群，其生物学品质与交配竞争力下降。本研究针对全球分布的11个自然地中海实蝇种群（涵盖欧洲、非洲、澳大利亚及美洲）的265头成虫，采用基于16S rRNA基因的扩增子测序技术（靶向V3-V4高变区，扩增片段长度460 bp）分析其肠道共生菌群。细菌群落的α多样性与β多样性分析结果表明，共生菌群整体多样性有所降低，且地理位置对细菌群落组成具有显著影响。