ABSTRACT: Comparative transcriptome analysis of Pagurus lanuginosus and Pagurus maculosus, with special reference to pigment-related genes in marine crustaceans
Project description:Thermomyces lanuginosus is a thermophilic fungus whose genome encodes many carbohydrate-active enzymes involved in Avicel degradation. This study examined and compared the transcriptomes of T. lanuginosus during cultivation on Avicesl or glucose. We identified approximately 4485 genes that showed expression differences when T. lanuginosus was cultured on Avicel compared to glucose. Functional annotation of up-regulated genes showed enrichment for proteins predicted to be involved in Avicel degradation, but also many genes encoding proteins of unknown function. Our study represents the first analysis of transcriptomes, with biologic replicates, generated by RNA-seq technology. We conclude that RNA-seq based transcriptome characterization would expedite genetic network analyses and permit the dissection of complex biologic functions.
Project description:Thermomyces lanuginosus is a thermophilic fungus whose genome encodes many carbohydrate-active enzymes involved in Avicel degradation. This study examined and compared the transcriptomes of T. lanuginosus during cultivation on Avicesl or glucose. We identified approximately 4485 genes that showed expression differences when T. lanuginosus was cultured on Avicel compared to glucose. Functional annotation of up-regulated genes showed enrichment for proteins predicted to be involved in Avicel degradation, but also many genes encoding proteins of unknown function. Our study represents the first analysis of transcriptomes, with biologic replicates, generated by RNA-seq technology. We conclude that RNA-seq based transcriptome characterization would expedite genetic network analyses and permit the dissection of complex biologic functions. mRNA profiles of 2-day old Thermomyces lanuginosus were generated by deep sequencing,in duplicate, using Illumina GAIIx.
Project description:A variety of contaminants find their way to the marine sediments from different sources, and these contaminants can pose serious risks to the natural marine flora and fauna. For example, pyrethroids, which are a potent pesticide family, are often used in agriculture fields worldwide, and these find their way into the marine environment through run off. Further, pyrethroids are used in farmed Atlantic salmon cages in Chile, Great Britain and Norway. Ammonia is another contaminant that is used in agriculture in form of ammonia-rich fertilizer and can be carried during run-offs to localized rivers and streams. Ammonia is also detectable after emission of effluents from sewage treatment plants and industrial plants like oil refineries and meat processing plants. Contaminants may have short and long term effects on non-target organisms living in the water column or in the marine sediment. Importantly, the sediment ecosystem houses a variety of plants, animals and crustaceans, including the American lobster Homarus americanus. Lobster is the most fished crustacean in New Brunswick and Quebec and its resale and exportation produced over $1.6 billion in 2011. Due to its economic and environmental importance, it is essential to study the effects of contaminants present in its ecosystem. Sediment samples are often used as pollution markers during toxicity testing due to their tendency to accumulate hydrophobic contaminants. To better understand the possible effects of contaminants in sediment, a total gene expression study was developed using the marine amphipod Eohaustorius estuarius. A 10 day spike-in exposure was performed using ammonia and two pyrethroids, namely cypermethrin and deltamethrin. As pyrethroids and ammonia are known to have vastly different mechanisms of action in living organisms, we compared global gene expression patterns following exposure to ammonia against the patterns observed following exposure to pyrethroids. Total gene expression was measured by oligonucleotide microarray. The expression of five genes of interest involved in different biological processes such as metabolism, transcription, translation, immunity and stress, which were found to be differently expressed by microarray, was validated by RT-qPCR. A set of genes was identified that showed differential expression levels in a treatment-dependent manner, thus further highlighting the different mechanisms of action of ammonia and pyrethroids in the marine sediment. This study provides a proof of concept for the use of DNA microarrays with model crustaceans for the study of marine sediment contaminants.
Project description:A variety of contaminants find their way to the marine sediments from different sources, and these contaminants can pose serious risks to the natural marine flora and fauna. For example, pyrethroids, which are a potent pesticide family, are often used in agriculture fields worldwide, and these find their way into the marine environment through run off. Further, pyrethroids are used in farmed Atlantic salmon cages in Chile, Great Britain and Norway. Ammonia is another contaminant that is used in agriculture in form of ammonia-rich fertilizer and can be carried during run-offs to localized rivers and streams. Ammonia is also detectable after emission of effluents from sewage treatment plants and industrial plants like oil refineries and meat processing plants. Contaminants may have short and long term effects on non-target organisms living in the water column or in the marine sediment. Importantly, the sediment ecosystem houses a variety of plants, animals and crustaceans, including the American lobster Homarus americanus. Lobster is the most fished crustacean in New Brunswick and Quebec and its resale and exportation produced over $1.6 billion in 2011. Due to its economic and environmental importance, it is essential to study the effects of contaminants present in its ecosystem. Sediment samples are often used as pollution markers during toxicity testing due to their tendency to accumulate hydrophobic contaminants. To better understand the possible effects of contaminants in sediment, a total gene expression study was developed using the marine amphipod Eohaustorius estuarius. A 10 day spike-in exposure was performed using ammonia and two pyrethroids, namely cypermethrin and deltamethrin. As pyrethroids and ammonia are known to have vastly different mechanisms of action in living organisms, we compared global gene expression patterns following exposure to ammonia against the patterns observed following exposure to pyrethroids. Total gene expression was measured by oligonucleotide microarray. The expression of five genes of interest involved in different biological processes such as metabolism, transcription, translation, immunity and stress, which were found to be differently expressed by microarray, was validated by RT-qPCR. A set of genes was identified that showed differential expression levels in a treatment-dependent manner, thus further highlighting the different mechanisms of action of ammonia and pyrethroids in the marine sediment. This study provides a proof of concept for the use of DNA microarrays with model crustaceans for the study of marine sediment contaminants. This specific study is aimed at evaluating the effect of ammonia and pyrethroid exposure on E.estuarius and to identify possible biomarkers of these exposures.
Project description:Polyamines, such as putrescine and spermidine, are aliphatic organic compounds with multiple amino groups. They are found ubiquitously in marine systems. However, compared with the extensive studies on the concentration and fate of other dissolved organic nitrogen compounds in seawater, such as dissolved free amino acids (DFAA), investigations of bacterially-mediated polyamine transformations have been rare. Bioinformatic analysis identified genes encoding polyamine transporters in 74 of 109 marine bacterial genomes surveyed, a surprising frequency for a class of organic nitrogen compounds not generally recognized as an important source of carbon and nitrogen for marine bacterioplankton. The genome sequence of marine model bacterium Silicibacter pomeroyi DSS-3 contains a number of genes putatively involved in polyamine use, including six four-gene ATP-binding cassette transport systems. In the present study, polyamine uptake and metabolism by S. pomeroyi was examined to confirm the role of putative polyamine-related genes, and to investigate how well current gene annotations reflect function. A comparative whole-genome microarray approach (Bürgmann et al., 2007) allowed us to identify key genes for transport and metabolism of spermidine in this bacterium, and specify candidate genes for in situ monitoring of polyamine transformations in marine bacterioplankton communities. Silicibacter pomeroyi DSS-3 cells were grown in chemostat in a modified marine basal medium (MBM) containing spermidine as sole carbon and nitrogen source. Serine was used as a substrate to provide comparative data for an amino acid. After reach stable condition, total RNA were extracted, mRNA were purified and aa-aRNA were amplified and fluoresently labled before hybridize on array chips. The array design is described in Burgmann et al., 2007