Metabolic Cooperation among Commensal Bacteria Supports Drosophila Juvenile Growth under Nutritional Stress

SUMMARYThe gut microbiota shapes animal growth trajectory in stressful nutritional environments, but the molecular mechanisms behind such physiological benefits remain poorly understood. The gut microbiota is mostly composed of bacteria, which construct metabolic networks among themselves and with the host. Until now, how the metabolic activities of the microbiota contribute to host juvenile growth remains unknown. Here, using Drosophila as a host model, we report that two of its major bacterial partners, Lactobacillus plantarum and Acetobacter pomorum engage in a beneficial metabolic dialogue that boosts host juvenile growth despite nutritional stress. We pinpoint that lactate, produced by L. plantarum, is utilized by A. pomorum as an additional carbon source, and A. pomorum provides essential amino-acids and vitamins to L. plantarum. Such bacterial cross-feeding provisions a set of anabolic metabolites to the host, which may foster host systemic growth despite poor nutrition.GRAPHICAL ABSTRACTHIGHLIGHTSL. plantarum feeds lactate to A. pomorumA. pomorum supplies essential amino acids and vitamins to L. plantarumMicrobiota metabolic dialogue boosts Drosophila’s larval growthLactate utilization by Acetobacter releases anabolic metabolites to larvae

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Commensal bacteria act as a broad genetic buffer in Drosophila during chronic under-nutrition

10.1101/334342 ◽

2018 ◽

Author(s):

Dali Ma ◽

Maroun Bou-Sleiman ◽

Pauline Joncour ◽

Claire-Emmanuelle Indelicato ◽

Michael Frochaux ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Gut Microbiota ◽

Nutritional Stress ◽

Commensal Bacteria ◽

Phenotypic Traits ◽

Oxygen Species ◽

Expression Variation ◽

Under Nutrition ◽

Phenotypic Robustness ◽

Eukaryotic Genomes

SummaryEukaryotic genomes encode several well-studied buffering mechanisms that robustly maintain invariant phenotypic outcome despite fluctuating environmental conditions. Here we show that the gut microbiota, represented by a single Drosophila facultative symbiont, Lactobacillus plantarum (LpWJL), acts also as a broad genetic buffer that masks the contribution of the cryptic genetic variations in the host under nutritional stress. During chronic under-nutrition, LpWJL consistently reduces variation in different host phenotypic traits and ensures robust organ patterning; LpWJL also decreases genotype-dependent expression variation, particularly for development-associated genes. We further demonstrate that LpWJL buffers via reactive oxygen species (ROS) signaling whose inhibition severely impairs microbiota-mediated phenotypic robustness. We thus identified an unexpected contribution of facultative symbionts to Drosophila fitness by assuring developmental robustness and phenotypic homogeneity in times of nutritional stress.

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Commensal bacteria differentially shape the nutritional requirements of Drosophila during juvenile growth

10.1101/728774 ◽

2019 ◽

Author(s):

Jessika Consuegra ◽

Théodore Grenier ◽

Patrice Baa-Puyoulet ◽

Isabelle Rahioui ◽

Houssam Akherraz ◽

...

Keyword(s):

Gut Microbiota ◽

Large Scale ◽

Larval Growth ◽

Commensal Bacteria ◽

Nutritional Deficiencies ◽

Nutritional Requirements ◽

Juvenile Growth ◽

Bacterial Strains ◽

Metabolic Intermediate ◽

The Impact

AbstractThe interplay between nutrition and the microbial communities colonizing the gastro-intestinal tract (i.e. gut microbiota) determines juvenile growth trajectory. Nutritional deficiencies trigger developmental delays, and an immature gut microbiota is a hallmark of pathologies related to childhood undernutrition. However, how commensal bacteria modulate the impact of nutrition on juvenile growth remains elusive. Here, using gnotobiotic Drosophila melanogaster larvae independently associated with two model commensal bacterial strains, Acetobacter pomorumWJL (ApWJL) and Lactobacillus plantarumNC8 (LpNC8), we performed a large-scale, systematic nutritional screen based on larval growth in 40 different and precisely controlled nutritional environments. We combined these results with genome-based metabolic network reconstruction to define the biosynthetic capacities of Drosophila germ-free (GF) larvae and its two commensal bacteria. We first established that ApWJL and LpNC8 differentially fulfills the nutritional requirements of the ex-GF larvae and parsed such difference down to individual amino acids, vitamins, other micronutrients and trace metals. We found that Drosophila commensal bacteria not only fortify the host’s diet with essential nutrients but, in specific instances, functionally compensate for host auxotrophies, by either providing a metabolic intermediate or nutrient derivative to the host or by uptaking, concentrating and sparing contaminant traces of micronutrients. Our systematic work reveals that, beyond the molecular dialogue engaged between the host and its commensal partners, Drosophila and its facultative bacterial partners establish an integrated nutritional network relying on nutrients sparing and utilization.

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Quantitative EM of gap junction distribution in mutant drosophila wing discs

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077177 ◽

1983 ◽

Vol 41 ◽

pp. 720-721

Author(s):

J.S. Ryerse

Keyword(s):

Gap Junctions ◽

Growth Control ◽

Intercellular Junctions ◽

Wing Disc ◽

En Bloc ◽

Metabolic Cooperation ◽

Drosophila Wing ◽

Adult Wing ◽

Wing Discs ◽

Wing Pouch

Gap junctions are intercellular junctions found in both vertebrates and invertebrates through which ions and small molecules can pass. Their distribution in tissues could be of critical importance for ionic coupling or metabolic cooperation between cells or for regulating the intracellular movement of growth control and pattern formation factors. Studies of the distribution of gap junctions in mutants which develop abnormally may shed light upon their role in normal development. I report here the distribution of gap junctions in the wing pouch of 3 Drosophila wing disc mutants, vg (vestigial) a cell death mutant, 1(2)gd (lethal giant disc) a pattern abnormality mutant and 1(2)gl (lethal giant larva) a neoplastic mutant and compare these with wildtype wing discs.The wing pouch (the anlagen of the adult wing blade) of a wild-type wing disc is shown in Fig. 1 and consists of columnar cells (Fig. 5) joined by gap junctions (Fig. 6). 14000x EMs of conventionally processed, UA en bloc stained, longitudinally sectioned wing pouches were enlarged to 45000x with a projector and tracings were made on which the lateral plasma membrane (LPM) and gap junctions were marked.

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