Comandatore Francesco, Damiani Claudia, Cappelli Alessia, Ribolla Paulo Eduardo Martins, Gasperi Giuliano, Gradoni Francesco, Capelli Gioia, Piazza Aurora, Montarsi Fabrizio, Mancini Maria Vittoria, Rossi Paolo, Ricci Irene, Bandi Claudio, Favia Guido
Pediatric CRC Romeo ed Enrica Invernizzi, Department of Biosciences, Università di Milano, Milan, Italy.
School of Biosciences & Veterinary Medicine, University of Camerino, Camerino, MC, Italy.
mBio. 2021 Mar 30;12(2):e00106-21. doi: 10.1128/mBio.00106-21.
The mosquito microbiota is composed of several lineages of microorganisms whose ecological roles and evolutionary histories have yet to be investigated in depth. Among these microorganisms, bacteria play a prominent role, given their abundance in the gut, reproductive organs, and salivary glands of different mosquito species, while their presence has also been reported in several other insects. Notably, has great potential as a tool for the control of mosquito-borne diseases. Here, we present a wide phylogenomic analysis of strains isolated from different species of mosquito vectors and from different populations of the Mediterranean fruit fly (medfly), , an insect pest of worldwide economic importance. We show that phylogenetically distant lineages of experienced independent genome reductions, despite following a common pattern, characterized by the early loss of genes involved in genome stability. This result highlights the role of specific metabolic pathways in the symbiotic relationship between and the insect host. Finally, we discovered that all but one of the strains included in the study possess the pyrethroid hydrolase gene. Phylogenetic analysis revealed that this gene is ancestral in , strongly suggesting that it played a role in the establishment of the symbiotic association between these bacteria and the mosquito hosts. We propose that this gene from the symbiont contributed to initial pyrethroid resistance in insects harboring , also considering the widespread production of pyrethrins by several plants. We have studied genome reduction within several strains of the insect symbiont isolated from different species/strains of mosquito and medfly. Phylogenetically distant strains of , despite following a common pattern involving the loss of genes related to genome stability, have undergone independent genome reductions, highlighting the peculiar role of specific metabolic pathways in the symbiotic relationship between and its host. We also show that the pyrethroid hydrolase gene is present in all the strains isolated except for the South American malaria vector , for which resistance to pyrethroids has never been reported, suggesting a possible involvement of in determining resistance to insecticides.
蚊子的微生物群由多个微生物谱系组成，其生态作用和进化历史尚未得到深入研究。在这些微生物中，细菌发挥着重要作用，因为它们在不同蚊子种类的肠道、生殖器官和唾液腺中大量存在，同时在其他几种昆虫中也有发现。值得注意的是，作为控制蚊媒疾病的工具具有巨大潜力。在这里，我们对从不同种类的蚊子媒介以及地中海实蝇（一种具有全球经济重要性的害虫）的不同种群中分离出的菌株进行了广泛的系统基因组分析。我们表明，尽管遵循共同模式，但系统发育上距离较远的菌株经历了独立的基因组缩减，其特征是参与基因组稳定性的基因早期丢失。这一结果凸显了特定代谢途径在与昆虫宿主共生关系中的作用。最后，我们发现研究中除一株外的所有菌株都拥有拟除虫菊酯水解酶基因。系统发育分析表明，该基因在中是祖先基因，强烈表明它在这些细菌与蚊子宿主之间共生关系的建立中发挥了作用。我们认为，共生体中的这个基因促成了携带的昆虫对拟除虫菊酯的初始抗性，同时也考虑到几种植物广泛产生除虫菊酯的情况。我们研究了从不同种类/品系的蚊子和地中海实蝇中分离出的昆虫共生体的几个菌株内的基因组缩减情况。尽管遵循涉及与基因组稳定性相关基因丢失的共同模式，但系统发育上距离较远的菌株经历了独立的基因组缩减，凸显了特定代谢途径在与其宿主共生关系中的特殊作用。我们还表明，除南美疟蚊外，所有分离出的菌株都存在拟除虫菊酯水解酶基因，而南美疟蚊从未有过对拟除虫菊酯抗性的报道，这表明可能参与了对杀虫剂抗性的决定。
