Project description:cDNA library sequencing in the midgut, mixed segment and first proctodeal segment of worker termites in Nasutitermes takasagoensis by 454 GS Junior pyrosequencing
Project description:The largest of the tuna species, Atlantic bluefin tuna, Thunnus thynnus (Linnaeus, 1758), inhabits the North Atlantic Ocean and the Mediterranean Sea and is considered to be an endangered species, largely through overfishing. Thus, the development of aquaculture practices independent of wild resources can provide an important contribution towards ensuring security and sustainability of this species in the longer-term. In order to provide a resource for ongoing studies, we have used 454 pyrosequencing technology to sequence a mixed-tissue normalized cDNA library, derived from adult individuals. Transcript sequences were used to develop a novel 15K Agilent oligo microarray for T. thynnus and comparative tissue gene expression profiles were inferred for gill, heart, liver, ovaries and testes.
Project description:Phylogeny and the distribution of symbiotic bacteria in the mixed segment of the wood-eating termite Nasutitermes takasagoensis (Shiraki) were studied. Bacterial 16S rRNA genes (rDNA) were amplified from the mixed segment of the gut by PCR, and two kinds of sequences were identified. The phylogenetic tree was constructed by neighbor-joining and maximum parsimony methods to identify symbionts harbored in the mixed segment. They are classified as low-G+C-content gram-positive bacteria and are most closely related to the genus Clostridium. The distribution of these bacteria throughout the whole gut was examined by PCR using specific primers, which suggested that they are confined to the mixed segment despite the presence of bacteria throughout the gut. In situ hybridization indicated that the symbiotic bacteria were localized to the ectoperitrophic space between the midgut wall and the peritrophic membrane in the mixed segment. Electron microscopy revealed the close association between these bacteria and the mesenteric epithelium, suggesting that they have some interactions with the gut tissue of termites.
Project description:In this work, 454 pyrosequencing was used to build up a 3’ cDNA fragment library from a normalized library constructed from pooled RNA samples extracted at different stages of A. quisqualis mycoparasitization process (recognition, early and late parasitization). An extensive catalogue of unique transcripts was compiled and used to develop a microarray for large-scale analysis of genes involved in this mycoparasitism. We examined the transcriptomic changes that occur during the first stage of mycoparasitism (conidial germination). Our results showed that 1,776 transcripts are regulated during germination in the presence of powdery mildew. A striking feature of the gene catalogue was the presence of a number of genes predicted to encode proteins involved in the production of, glucanases, chitinases and extracellular proteases. This suggests that A. quisqualis causes the degradation of powdery mildew macromolecular constituents to provide the carbon skeletons and energy for the synthesis of proteins and other components destined for the developing of the mycelium.
