Exemplar Abstract for Buchnera aphidicola Munson et al. 1991.

Abstract Background Host/symbiont integration is a signature of evolutionarily ancient, obligate endosymbioses. However, little is known about the cellular and developmental mechanisms of host/symbiont integration at the molecular level. Many insects possess obligate bacterial endosymbionts that provide essential nutrients. To advance understanding of the developmental and metabolic integration of hosts and endosymbionts, we track the localization of a non-essential amino acid transporter, ApNEAAT1, across asexual embryogenesis in the aphid, Acyrthosiphon pisum. Previous work in adult bacteriomes revealed that ApNEAAT1 functions to exchange non-essential amino acids at the A. pisum/Buchnera aphidicola symbiotic interface. Driven by amino acid concentration gradients, ApNEAAT1 moves proline, serine, and alanine from A. pisum to Buchnera and cysteine from Buchnera to A. pisum. Here, we test the hypothesis that ApNEAAT1 is localized to the symbiotic interface during asexual embryogenesis. Results During A. pisum asexual embryogenesis, ApNEAAT1 does not localize to the symbiotic interface. We observed ApNEAAT1 localization to the maternal follicular epithelium, the germline, and, in late-stage embryos, to anterior neural structures and insect immune cells (hemocytes). We predict that ApNEAAT1 provisions non-essential amino acids to developing oocytes and embryos, as well as to the brain and related neural structures. Additionally, ApNEAAT1 may perform roles related to host immunity. Conclusions Our work provides further evidence that the embryonic and adult bacteriomes of asexual A. pisum are not equivalent. Future research is needed to elucidate the developmental time point at which the bacteriome reaches maturity.

Download Full-text

Matching the supply of bacterial nutrients to the nutritional demand of the animal host

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2014.1163 ◽

2014 ◽

Vol 281 (1791) ◽

pp. 20141163 ◽

Cited By ~ 32

Author(s):

Calum W. Russell ◽

Anton Poliakov ◽

Meena Haribal ◽

Georg Jander ◽

Klaas J. van Wijk ◽

...

Keyword(s):

Quantitative Proteomics ◽

Acyrthosiphon Pisum ◽

Feedback Inhibition ◽

Essential Amino Acids ◽

Host Cells ◽

Host Proteins ◽

Buchnera Aphidicola ◽

Symbiotic Microorganisms ◽

Precursor Supply ◽

Host Regulation

Various animals derive nutrients from symbiotic microorganisms with much-reduced genomes, but it is unknown whether, and how, the supply of these nutrients is regulated. Here, we demonstrate that the production of essential amino acids (EAAs) by the bacterium Buchnera aphidicola in the pea aphid Acyrthosiphon pisum is elevated when aphids are reared on diets from which that EAA are omitted, demonstrating that Buchnera scale EAA production to host demand. Quantitative proteomics of bacteriocytes (host cells bearing Buchnera ) revealed that these metabolic changes are not accompanied by significant change in Buchnera or host proteins, suggesting that EAA production is regulated post-translationally. Bacteriocytes in aphids reared on diet lacking the EAA methionine had elevated concentrations of both methionine and the precursor cystathionine, indicating that methionine production is promoted by precursor supply and is not subject to feedback inhibition by methionine. Furthermore, methionine production by isolated Buchnera increased with increasing cystathionine concentration. We propose that Buchnera metabolism is poised for EAA production at certain maximal rates, and the realized release rate is determined by precursor supply from the host. The incidence of host regulation of symbiont nutritional function via supply of key nutritional inputs in other symbioses remains to be investigated.

Download Full-text

Aphid endosymbiont facilitates virus transmission by modulating the volatile profile of host plants

BMC Plant Biology ◽

10.1186/s12870-021-02838-5 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Xiao-Bin Shi ◽

Shuo Yan ◽

Chi Zhang ◽

Li-Min Zheng ◽

Zhan-Hong Zhang ◽

...

Keyword(s):

Host Plants ◽

Green Peach Aphid ◽

Virus Transmission ◽

Feeding Preference ◽

Plant Viruses ◽

Volatile Profile ◽

Cmv Infection ◽

Buchnera Aphidicola ◽

Plant Volatile ◽

Volatile Profiles

Abstract Background Most plant viruses rely on vectors for their transmission and spread. One of the outstanding biological questions concerning the vector-pathogen-symbiont multi-trophic interactions is the potential involvement of vector symbionts in the virus transmission process. Here, we used a multi-factorial system containing a non-persistent plant virus, cucumber mosaic virus (CMV), its primary vector, green peach aphid, Myzus persicae, and the obligate endosymbiont, Buchnera aphidicola to explore this uncharted territory. Results Based on our preliminary research, we hypothesized that aphid endosymbiont B. aphidicola can facilitate CMV transmission by modulating plant volatile profiles. Gene expression analyses demonstrated that CMV infection reduced B. aphidicola abundance in M. persicae, in which lower abundance of B. aphidicola was associated with a preference shift in aphids from infected to healthy plants. Volatile profile analyses confirmed that feeding by aphids with lower B. aphidicola titers reduced the production of attractants, while increased the emission of deterrents. As a result, M. persicae changed their feeding preference from infected to healthy plants. Conclusions We conclude that CMV infection reduces the B. aphidicola abundance in M. persicae. When viruliferous aphids feed on host plants, dynamic changes in obligate symbionts lead to a shift in plant volatiles from attraction to avoidance, thereby switching insect vector’s feeding preference from infected to healthy plants.

Download Full-text

Coexistence of Wolbachia with Buchnera aphidicola and a Secondary Symbiont in the Aphid Cinara cedri

Journal of Bacteriology ◽

10.1128/jb.186.19.6626-6633.2004 ◽

2004 ◽

Vol 186 (19) ◽

pp. 6626-6633 ◽

Cited By ~ 92

Author(s):

Laura Gómez-Valero ◽

Mario Soriano-Navarro ◽

Vicente Pérez-Brocal ◽

Abdelaziz Heddi ◽

Andrés Moya ◽

...

Keyword(s):

Bacterial Genome ◽

Pcr Amplification ◽

Bacterial Cells ◽

Buchnera Aphidicola ◽

Rdna Genes ◽

16S Ribosomal Dna ◽

Secondary Symbiont ◽

Rdna Sequences ◽

16S Rdna Sequences

ABSTRACT Intracellular symbiosis is very common in the insect world. For the aphid Cinara cedri, we have identified by electron microscopy three symbiotic bacteria that can be characterized by their different sizes, morphologies, and electrodensities. PCR amplification and sequencing of the 16S ribosomal DNA (rDNA) genes showed that, in addition to harboring Buchnera aphidicola, the primary endosymbiont of aphids, C. cedri harbors a secondary symbiont (S symbiont) that was previously found to be associated with aphids (PASS, or R type) and an α-proteobacterium that belongs to the Wolbachia genus. Using in situ hybridization with specific bacterial probes designed for symbiont 16S rDNA sequences, we have shown that Wolbachia was represented by only a few minute bacteria surrounding the S symbionts. Moreover, the observed B. aphidicola and the S symbionts had similar sizes and were housed in separate specific bacterial cells, the bacteriocytes. Interestingly, in contrast to the case for all aphids examined thus far, the S symbionts were shown to occupy a similarly sized or even larger bacteriocyte space than B. aphidicola. These findings, along with the facts that C. cedri harbors the B. aphidicola strain with the smallest bacterial genome and that the S symbionts infect all Cinara spp. analyzed so far, suggest the possibility of bacterial replacement in these species.

Download Full-text