Project description:Uric acid stored in the fat body of cockroaches is a nitrogen reservoir mobilized in times of scarcity. The discovery of urease in Blattabacterium cuenoti, the primary endosymbiont of cockroaches, suggests that the endosymbiont may participate in cockroach nitrogen economy. However, bacterial urease may only be one piece in the entire nitrogen recycling process from insect uric acid. Thus, in addition to the uricolytic pathway to urea, there must be glutamine synthetase assimilating the released ammonia by the urease reaction to enable the stored nitrogen to be metabolically usable. None of the Blattabacterium genomes sequenced to date possess genes encoding for those enzymes. To test the host's contribution to the process, we have sequenced and analysed Blattella germanica transcriptomes from the fat body. We identified transcripts corresponding to all genes necessary for the synthesis of uric acid and its catabolism to urea, as well as for the synthesis of glutamine, asparagine, proline and glycine, i.e. the amino acids required by the endosymbiont. We also explored the changes in gene expression with different dietary protein levels. It appears that the ability to use uric acid as a nitrogen reservoir emerged in cockroaches after its age-old symbiotic association with bacteri
Project description:Transcriptome analysis of Wigglesworthia glossinidia endosymbiont derived from control samples with or without parasite contact at 10 days. Expression profiling by array - Wigglesworthia glossinidia endosymbiont of Glossina morsitans morsitans
Project description:Transcriptome analysis of Wigglesworthia glossinidia endosymbiont derived from uninfected and infected samples at 3 time points (3, 10 and 20 days). Expression profiling by array - Wigglesworthia glossinidia endosymbiont of Glossina morsitans morsitans
Project description:The majority of bacterial genomes have high coding efficiencies, but there are an few genomes of the intracellular bacteria that have low gene density. The genome of the endosymbiont Sodalis glossinidius contains almost 50% pseudogenes containing mutations that putatively silence them at the genomic level. We have applied multiple omic strategies: combining single molecule DNA-sequencing and annotation; stranded RNA-sequencing and proteome analysis to better understand the transcriptional and translational landscape of Sodalis pseudogenes, and potential mechanisms for their control. Between 53% and 74% of the Sodalis transcriptome remains active in cell-free culture. Mean sense transcription from Coding Domain Sequences (CDS) is four-times greater than that from pseudogenes. Core-genome analysis of six Illumina sequenced Sodalis isolates from different host Glossina species shows pseudogenes make up ~40% of the 2,729 genes in the core genome, suggesting are stable and/or Sodalis is a recent introduction across the Glossina genus as a facultative symbiont. These data further shed light on the importance of transcriptional and translational control in deciphering host-microbe interactions, and demonstrate that pseudogenes are more complex than a simple degrading DNA sequence. For this reason, we show that combining genomics, transcriptomics and proteomics represents an important resource for studying prokaryotic genomes with a view to elucidating evolutionary adaptation to novel environmental niches.
Project description:Transcriptome analysis of Wigglesworthia glossinidia endosymbiont derived from control samples with or without parasite contact at 10 days. Expression profiling by array - Wigglesworthia glossinidia endosymbiont of Glossina morsitans morsitans RNAs are a mix of Wigglesworthia, Sodalis and glossina. RNAs were extracted from 8 samples including 2 conditions (with 4 replicates per condition).
Project description:Endosymbiotic bacteria associated with eukaryotic hosts are omnipresent in nature, particularly in insects. Studying the bacterial side of host-symbiont interactions is, however, often limited by the unculturability and genetic intractability of the symbionts. Spiroplasma poulsonii is a maternally transmitted bacterial endosymbiont that is naturally associated with several Drosophila species. S. poulsonii strongly affects its host’s physiology, for example by causing male killing or by protecting it against various parasites. Despite intense work on this model since the 1950s, attempts to cultivate endosymbiotic Spiroplasma in vitro have failed so far. Here, we developed a method to sustain the in vitro culture of S. poulsonii by optimizing a commercially accessible medium. We also provide a complete genome assembly, including the first sequence of a natural plasmid of an endosymbiotic Spiroplasma species. Last, by comparing the transcriptome of the in vitro culture to the transcriptome of bacteria extracted from the host, we identified genes putatively involved in host-symbiont interactions. This work provides new opportunities to study the physiology of endosymbiotic Spiroplasma and paves the way to dissect insect-endosymbiont interactions with two genetically tractable partners.
Project description:Aspergillus flavus and A. oryzae represent two unique species predicted to have spent centuries in vastly different environments. A. flavus is an important opportunistic plant pathogen known for contaminating crops with the carcinogenic mycotoxin, aflatoxin and A. oryzae is a domesticated fungus used in food fermentations. Remarkably, the genomes of these two species are still nearly identical. We have used the recently sequenced genomes of A. oryzae RIB40 and A. flavus NRRL3357 along with array based comparative genome hybridization (CGH) as a tool to compare genomes across several strains of these two species. A comparison of three strains from each species by CGH revealed only 42 and 129 genes unique to A. flavus and A. oryzae, respectively. Further, only 709 genes were identified as being polymorphic between the species. Despite the high degree of similarity between these two species, correlation analysis among all data from the CGH arrays for all strains used in this study reveals a species split. However, this view of species demarcation becomes muddled when focused on only those genes for secondary metabolism.