title: Deep sequencing of ESTs from nacreous and prismatic layer producing tissues and a screen for novel shell formation-related genes in the pearl oyster.
abstract: BACKGROUND
  Despite its economic importance, we have a limited understanding of the molecular mechanisms underlying shell formation in pearl oysters, wherein the calcium carbonate crystals, nacre and prism, are formed in a highly controlled manner. We constructed comprehensive expressed gene profiles in the shell-forming tissues of the pearl oyster Pinctada fucata and identified novel shell formation-related genes candidates.
  
  
  RESULTS
  We employed the GS FLX 454 system and constructed transcriptome data sets from pallial mantle and pearl sac, which form the nacreous layer, and from the mantle edge, which forms the prismatic layer in P. fucata. We sequenced 260477 reads and obtained 29682 unique sequences. We also screened novel nacreous and prismatic gene candidates by a combined analysis of sequence and expression data sets, and identified various genes encoding lectin, protease, protease inhibitors, lysine-rich matrix protein, and secreting calcium-binding proteins. We also examined the expression of known nacreous and prismatic genes in our EST library and identified novel isoforms with tissue-specific expressions.
  
  
  CONCLUSIONS
  We constructed EST data sets from the nacre- and prism-producing tissues in P. fucata and found 29682 unique sequences containing novel gene candidates for nacreous and prismatic layer formation. This is the first report of deep sequencing of ESTs in the shell-forming tissues of P. fucata and our data provide a powerful tool for a comprehensive understanding of the molecular mechanisms of molluscan biomineralization.
authors: Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan.
authors: Shigeharu
authors: S
authors: Kinoshita
authors: Ning
authors: N
authors: Wang
authors: Haruka
authors: H
authors: Inoue
authors: Kaoru
authors: K
authors: Maeyama
authors: Kikuhiko
authors: K
authors: Okamoto
authors: Kiyohito
authors: K
authors: Nagai
authors: Hidehiro
authors: H
authors: Kondo
authors: Ikuo
authors: I
authors: Hirono
authors: Shuichi
authors: S
authors: Asakawa
authors: Shugo
authors: S
authors: Watabe
mesh_terms: D000595:Amino Acid Sequence; D000825:Animal Structures / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D016000:Cluster Analysis; D018076:DNA, Complementary / Q000235:genetics; D020224:Expressed Sequence Tags / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D015723:Gene Library; D056726:Genetic Association Studies; D005820:Genetic Testing; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics*; D049911:Pinctada / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D018076:DNA, Complementary