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Evolution of host support for two ancient bacterial symbionts with differentially degraded genomes in a leafhopper host.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2018 Dec 11; Vol. 115 (50), pp. E11691-E11700. Date of Electronic Publication: 2018 Nov 21. - Publication Year :
- 2018
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Abstract
- Plant sap-feeding insects (Hemiptera) rely on bacterial symbionts for nutrition absent in their diets. These bacteria experience extreme genome reduction and require genetic resources from their hosts, particularly for basic cellular processes other than nutrition synthesis. The host-derived mechanisms that complete these processes have remained poorly understood. It is also unclear how hosts meet the distinct needs of multiple bacterial partners with differentially degraded genomes. To address these questions, we investigated the cell-specific gene-expression patterns in the symbiotic organs of the aster leafhopper (ALF), Macrosteles quadrilineatus (Cicadellidae). ALF harbors two intracellular symbionts that have two of the smallest known bacterial genomes: Nasuia (112 kb) and Sulcia (190 kb). Symbionts are segregated into distinct host cell types (bacteriocytes) and vary widely in their basic cellular capabilities. ALF differentially expresses thousands of genes between the bacteriocyte types to meet the functional needs of each symbiont, including the provisioning of metabolites and support of cellular processes. For example, the host highly expresses genes in the bacteriocytes that likely complement gene losses in nucleic acid synthesis, DNA repair mechanisms, transcription, and translation. Such genes are required to function in the bacterial cytosol. Many host genes comprising these support mechanisms are derived from the evolution of novel functional traits via horizontally transferred genes, reassigned mitochondrial support genes, and gene duplications with bacteriocyte-specific expression. Comparison across other hemipteran lineages reveals that hosts generally support the incomplete symbiont cellular processes, but the origins of these support mechanisms are generally specific to the host-symbiont system.<br />Competing Interests: The authors declare no conflict of interest.<br /> (Copyright © 2018 the Author(s). Published by PNAS.)
- Subjects :
- Animals
Bacterial Physiological Phenomena
Bacteroidetes genetics
Bacteroidetes physiology
Betaproteobacteria genetics
Betaproteobacteria physiology
Gene Duplication
Gene Transfer, Horizontal
Genome, Insect
Hemiptera cytology
Hemiptera genetics
Host Microbial Interactions physiology
Symbiosis physiology
Transcriptome
Bacteria genetics
Evolution, Molecular
Genome, Bacterial
Hemiptera microbiology
Host Microbial Interactions genetics
Symbiosis genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 115
- Issue :
- 50
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 30463949
- Full Text :
- https://doi.org/10.1073/pnas.1811932115