bioRxiv preprint doi: https://doi.org/10.1101/2021.04.18.440331; this version posted April 19, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Ubiquity of the Symbiont Serratia symbiotica in the Aphid Natural Environment: 2 Distribution, Diversity and Evolution at a Multitrophic Level 3 4 Inès Pons1*, Nora Scieur1, Linda Dhondt1, Marie-Eve Renard1, François Renoz1, Thierry Hance1 5 6 1 Earth and Life Institute, Biodiversity Research Centre, Université catholique de Louvain, 1348, 7 Louvain-la-Neuve, Belgium. 8 9 10 * Corresponding author: 11 Inès Pons 12 Croix du Sud 4-5, bte L7.07.04, 1348 Louvain la neuve, Belgique 13
[email protected] 14 15 16 17 18 19 20 21 22 23 24 1 bioRxiv preprint doi: https://doi.org/10.1101/2021.04.18.440331; this version posted April 19, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 25 ABSTRACT 26 Bacterial symbioses are significant drivers of insect evolutionary ecology. However, despite recent 27 findings that these associations can emerge from environmentally derived bacterial precursors, there 28 is still little information on how these potential progenitors of insect symbionts circulates in the trophic 29 systems. The aphid symbiont Serratia symbiotica represents a valuable model for deciphering 30 evolutionary scenarios of bacterial acquisition by insects, as its diversity includes intracellular host- 31 dependent strains as well as gut-associated strains that have retained some ability to live independently 32 of their hosts and circulate in plant phloem sap.