title: Deep transcriptome-sequencing and proteome analysis of the hydrothermal vent annelid Alvinella pompejana identifies the CvP-bias as a robust measure of eukaryotic thermostability.
abstract: BACKGROUND
  Alvinella pompejana is an annelid worm that inhabits deep-sea hydrothermal vent sites in the Pacific Ocean. Living at a depth of approximately 2500 meters, these worms experience extreme environmental conditions, including high temperature and pressure as well as high levels of sulfide and heavy metals. A. pompejana is one of the most thermotolerant metazoans, making this animal a subject of great interest for studies of eukaryotic thermoadaptation.
  
  
  RESULTS
  In order to complement existing EST resources we performed deep sequencing of the A. pompejana transcriptome. We identified several thousand novel protein-coding transcripts, nearly doubling the sequence data for this annelid. We then performed an extensive survey of previously established prokaryotic thermoadaptation measures to search for global signals of thermoadaptation in A. pompejana in comparison with mesophilic eukaryotes. In an orthologous set of 457 proteins, we found that the best indicator of thermoadaptation was the difference in frequency of charged versus polar residues (CvP-bias), which was highest in A. pompejana. CvP-bias robustly distinguished prokaryotic thermophiles from prokaryotic mesophiles, as well as the thermophilic fungus Chaetomium thermophilum from mesophilic eukaryotes. Experimental values for thermophilic proteins supported higher CvP-bias as a measure of thermal stability when compared to their mesophilic orthologs. Proteome-wide mean CvP-bias also correlated with the body temperatures of homeothermic birds and mammals.
  
  
  CONCLUSIONS
  Our work extends the transcriptome resources for A. pompejana and identifies the CvP-bias as a robust and widely applicable measure of eukaryotic thermoadaptation.
authors: Max-Planck-Institute for Developmental Biology, Spemannstr, 35, Tübingen, D-72076, Germany.
authors: Thomas
authors: T
authors: Holder
authors: Claire
authors: C
authors: Basquin
authors: Judith
authors: J
authors: Ebert
authors: Nadine
authors: N
authors: Randel
authors: Didier
authors: D
authors: Jollivet
authors: Elena
authors: E
authors: Conti
authors: Gáspár
authors: G
authors: Jékely
authors: Fulvia
authors: F
authors: Bono
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing; D006358:Hot Temperature; D060086:Hydrothermal Vents; D008297:Male; D010140:Pacific Ocean; D010802:Phylogeny; D011077:Polychaeta / Q000737:chemistry / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012313:RNA / Q000737:chemistry / Q000235:genetics; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D059467:Transcriptome
chemical_list: D018076:DNA, Complementary; D012313:RNA