RESUMO
Bacterial endosymbionts are common in all insects, and symbiosis has played an integral role in ant evolution. Atta sexdens rubropilosa leaf-cutting ants cultivate their symbiotic fungus using fresh leaves. They need to defend themselves and their brood against diseases, but they also need to defend their obligate fungus gardens, their primary food source, from infection, parasitism, and usurpation by competitors. This study aimed to characterize the microbial communities in whole workers and different tissues of A. sexdens rubropilosa queens using Ion Torrent NGS. Our results showed that the microbial community in the midgut differs in abundance and diversity from the communities in the postpharyngeal gland of the queen and in whole workers. The main microbial orders in whole workers were Lactobacillales, Clostridiales, Enterobacteriales, Actinomycetales, Burkholderiales, and Bacillales. In the tissues of the queens, the main orders were Burkholderiales, Clostridiales, Syntrophobacterales, Lactobacillales, Bacillales, and Actinomycetales (midgut) and Entomoplasmatales, unclassified γ-proteobacteria, and Actinomycetales (postpharyngeal glands). The high abundance of Entomoplasmatales in the postpharyngeal glands (77%) of the queens was an unprecedented finding. We discuss the role of microbial communities in different tissues and castes. Bacteria are likely to play a role in nutrition and immune defense as well as helping antimicrobial defense in this ant species.
Assuntos
Formigas/microbiologia , Microbiota , Animais , Biodiversidade , Metagenoma , Metagenômica , Especificidade de Órgãos , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
This study focuses on the weaver ant, Camponotus textor, Forel which occurs in some areas of the Brazilian Cerrado and Atlantic Forest, and its symbionts: Blochmannia, an obligate symbiont of Camponotus, and Wolbachia, known for causing reproductive alterations in their hosts. The main goal of this study was to investigate the presence, frequency of occurrence, and diversity of Wolbachia and Blochmannia strains in C. textor colonies. We found high infection rates (100%) and the occurrence of at least two distinct strains of Blochmannia (H_1 or H_7) in the same species. The observed haplotype variation within a single species may result from the high mutation rate of the symbiont. Similarly, the Wolbachia was found in all colonies with different rates of infections and a new strain (supergroup A) was deposited in the MLST database. The diversity found in the present study shows that there is still much to explore to understand about these symbiotic interactions.
Assuntos
Formigas/microbiologia , Bactérias , Fenômenos Fisiológicos Bacterianos , Simbiose , Animais , Bactérias/classificação , Bactérias/genética , Tipagem de Sequências Multilocus , Filogenia , RNA Ribossômico 16S/genética , Wolbachia/classificação , Wolbachia/genéticaRESUMO
The great diversity of Camponotus, high levels of geographic, intraspecific and morphological variation common to most species of this genus make the determination of the interspecific limits of Camponotus a complex task. The Cytochrome c oxidase 1 (COI) gene was sequenced in this study to serve as an auxiliary tool in the identification of two taxa of Camponotus thought to be morphologically similar. Additionally, characteristics related to nesting were described. Five to fifteen workers from twenty-one colonies were analyzed, collected from twigs scattered in the leaf litter and from trees located in different regions of Brazil. Phylogenetic reconstructions, haplotype network, and nesting strategies confirmed the existence of two species and that they correspond to Camponotus senex and Camponotus textor. Our results emphasize that the COI can be used as an additional tool for the identification of morphologically similar Camponotus species.