Genome-wide identification of cuticular protein genes in the silkworm, Bombyx mori

• Published in: Insect biochemistry and molecular biology Vol. 38; no. 12; pp. 1138 - 1146
• Main Authors: Futahashi, Ryo, Okamoto, Shun, Kawasaki, Hideki, Zhong, Yang-Sheng, Iwanaga, Masashi, Mita, Kazuei, Fujiwara, Haruhiko
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2008
• Subjects: amino acid motifs; Animals; Apis mellifera; Bombyx - genetics; Bombyx - metabolism; Bombyx mori; cDNA libraries; Cuticle; Cuticular protein; Drosophila melanogaster; EST library; Expressed Sequence Tags; gene annotation; gene expression; Gene Expression Profiling; gene expression regulation; Gene Expression Regulation - physiology; Gene Library; genes; genome; Genome, Insect; insect cuticle; insect proteins; Insect Proteins - genetics; Insect Proteins - metabolism; Integumentary System; molecular sequence data; multigene family; Phylogeny; R&R consensus; sequence homology; silkworms; Whole genome sequence; R&R consensus; Cuticle; Bombyx mori; Whole genome sequence; Cuticular protein; EST library
• ISSN: 0965-1748; 1879-0240
• DOI: 10.1016/j.ibmb.2008.05.007

Many kinds of cuticular proteins are found in a single insect species and their numbers and features are diversified among insects. Because there are so many cuticular proteins and so much sequence variation among them, an overview of cuticular protein gene is needed. Recently, a complete silkworm genome sequence was obtained through the integration of data from two whole genome sequence projects performed independently in 2004. To identify cuticular protein genes in the silkworm Bombyx mori exhaustively, we searched both the Bombyx whole genome sequence as well as various EST libraries, and found 220 putative cuticular protein genes. We also revised the annotation of the gene model, and named each identified cuticular protein based on its motif. The phylogenetic tree of cuticular protein genes among B. mori, Drosophila melanogaster, and Apis mellifera revealed that duplicate cuticular protein clusters have evolved independently among insects. Comparison of EST libraries and northern blot analyses showed that the tissue- and stage-specific expression of each gene was intricately regulated, even between adjacent genes in the same gene cluster. This study reveals many novel cuticular protein genes as well as insights into cuticular protein gene regulation.