Endosymbiosis morphological reorganization during metamorphosis diverges in weevils.

Virtually all animals associate with beneficial symbiotic bacteria. Whether and how these associations are modulated across a host's lifecycle is an important question in disentangling animal-bacteria interactions. We recently reported a case of complete morphological reorganization of symbiosis during metamorphosis of the cereal weevil, . In this model, the bacteriome, a specialized organ that houses the intracellular bacterium , undergoes a two-phase remodeling program synchronously driven by host and endosymbiont, resulting in a localization shift and the formation of multiple new bacteriomes. Here, we provide comparative data in a closely-related coleopteran, the red palm weevil , which is associated with the ancestral endosymbiont . Using cell imaging experiments, we show that the red pal weevil bacteriome remains unchanged during metamorphosis, hence contrasting with what we reported in the cereal weevil . These findings highlight the complexity and divergence of host-symbiont interactions and their intertwining with host development, even in closely-related species. : DAPI: 4',6-diamidino-2-phenylindole; FISH: Fluorescence hybridization; T3SS: Type III secretion system.