Impact of domestication of wild Anastrepha fraterculus on the gut bacterial community

SALGUEIRO, JULIETA; PIMPER, LIDA E.; SEGURA DIEGO F.; CLADERA, JORGE L; TSIAMIS, GEORGE; LANZAVECCHIA, SILVIA B.

Tapachula

Simposio; 10th International Symposium on Fruit lies of Economic Importance.; 2018

Background: The study of bacterial symbionts associated to Anastrepha fraterculus promotes innovations in the autocidal control of this pest. Changes in gut bacterial community caused by the adaptation of wild populations to laboratory conditions (domestication) may threaten the development of environmentally-friendly control strategies, such as the sterile insect technique. Under the hypothesis that the intestinal microbial community of A. fraterculus wild flies is modified during domestication, we proposed: 1) to compare the gut bacterial diversity between laboratory and wild flies; 2) to address potential changes in the bacterial community across generations due to domestication process; and 3) to evaluate whether the effects of domestication on gut bacterial communities is differentially associated to gender (male/female).Methods: A. fraterculus flies from three different origins were included in this study: 1) laboratory flies (LAB); 2) wild adult flies caught in tramps hanged from ubajay (Hexachlamys edulis) trees (WU); 3) wild flies sampled from infested feijoa (Feijoa sellowiana) fruits, and reared until the 6th generation under laboratory conditions (F0-F6). Adults fly guts were dissected from 15 males and 15 females and pulled in groups of 5 (N = 3). For LAB and F0-F6, gut samples were obtained at two different times after emergence: 0 days (teneral flies) and 15 days (15d). Gut bacteria were identified by Massively Parallel Sequencing (Illumina MiSeq) of V3-V4 region (550 bp) from the bacterial 16S ribosomal gene. Results: We found significant differences in microbiological profiles between wild flies (WU and F0) and LAB flies. WU and F0 flies presented groups of Proteobacteria that were not detected in LAB flies. The analysis of generations F1, F3 and F6, showed no differences between F6 and LAB in their gut bacterial community. Meanwhile, we observed that F1 and F3 statistically differed from LAB and showed the highest diversity of bacterial taxonomic groups. No significant differences were found between males and females. Furthermore, we detected a dominant pattern of Wolbachia in teneral flies (1 day-old, un-fed), whereas Enterobacter was found highly abundant at day 15 after emergence, independently from flies origin or sex. Conclusions: Laboratory and wild adults of A. fraterculus harbor different bacterial communities. Domestication process has an important impact on gut microbiota and involves structural changes no correlated to the gender of the fly. The observed differences between teneral and 15 days-old flies may represent the combined effects of physiological changes of the flies (e.g. age, nutrition) and environmental conditions (e.g. diet, managing and rearing settings). Further studies on the analysis of intestinal bacterial community in larval stage, and microbiological and biochemical analyses of identified isolates will contribute to understand the complex structure of gut microbiota and its role on the behavior and fitness of insects in the field.