About this Research Topic
Microbial symbionts of insects enable their hosts to thrive on nutritionally unbalanced diets or in adverse environmental conditions. These beneficial symbionts can live either extracellularly, in structures (e.g. caeca, calyxes, crypts, or chambers) corresponding to expansions or modifications of the gut or other organs, or intracellularly, inside specialized host cells (e.g. the bacteriocytes). Those symbiotic structures are biological innovations, pivotal for maintaining symbionts through host generations in both vertical transmission and horizontal/environmental acquisition. Symbiotic structures are more than a privileged environment to house symbionts. Recent advances on insect symbioses have indeed shown that both symbiont and bacteriocyte numbers appear to be dynamically regulated in function of the nutritional demand, environmental stresses or the age of the hosts. This suggests the presence of mechanisms active throughout the life cycle that regulate physiology and metabolism of these novel organs. However, the underlying mechanisms, as well as the genetic program regulating the development and morphogenesis of symbiotic organs remain poorly understood.
The availability of high quality insect genome sequences and new imaging technologies constitute a unique opportunity for in-depth studies of symbiont-symbiotic organs-whole individual interaction in individual species while at the same time facilitating comparative studies into (i) the evolutionary origin of symbiotic organs across species, (ii) the various ways in which symbionts subvert cellular mechanisms to invade and colonize the host tissues, and (iii) how bacteriocytes are integrated in, contribute to, host physiology and metabolism.
In this Research Topic, we aim to bring together studies that address all aspects of the relationships between the hosts, symbiotic organs and symbionts in insects with the purpose of stimulating scholarly interactions in this exciting field. We invite researchers to contribute original research, perspectives, reviews, opinion papers. Submission of studies using high-throughput technologies (proteomics, single cell RNA-seq, Dual-RNA-seq) is strongly encouraged.
The Research Topic will focus on studies that investigate and discuss:
1. Changes in symbiont and symbiotic organs structure (morphology/relationships with other organs/numbers of cells) throughout the life cycle of the host
2. Imaging, microscopy and ultrastructural analyses as tools to study symbiotic structures and bacteriocytes
3. Comparative studies on development, structure and function of symbiotic organs
4. Molecular machinery in symbiotic structures/cells/organs
5. Molecular and metabolic host-symbiont dialogue throughout symbiotic organ development, differentiation and homeostasis
6. Reconstruction of integrated symbiotic genetic and metabolic networks
7. Microbial endosymbiont metabolic and immune determinants contributing to the development and differentiation of symbiotic organs
8. Symbiont and symbiotic organ responses to nutritional challenge/environmental stress.
Keywords: Insects, Symbiotic organs, Bacteriocytes, Development, Metabolism
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.