title: A comprehensive analysis of the chorion locus in silkmoth.
abstract: Despite more than 40 years of intense study, essential features of the silkmoth chorion (eggshell) are still not fully understood. To determine the precise structure of the chorion locus, we performed extensive EST analysis, constructed a bacterial artificial chromosome (BAC) contig, and obtained a continuous genomic sequence of 871,711 base pairs. We annotated 127 chorion genes in two segments interrupted by a 164 kb region with 5 non-chorion genes, orthologs of which were on chorion bearing scaffolds in 4 ditrysian families. Detailed transcriptome analysis revealed expression throughout choriogenesis of most chorion genes originally categorized as "middle", and evidence for diverse regulatory mechanisms including cis-elements, alternative splicing and promoter utilization, and antisense RNA. Phylogenetic analysis revealed multigene family associations and faster evolution of early chorion genes and transcriptionally active pseudogenes. Proteomics analysis identified 99 chorion proteins in the eggshell and micropyle localization of 1 early and 6 Hc chorion proteins.
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Kirin Brewery Co. Ltd, Toride, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Nohata
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Huizhen
authors.initials: H
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Shenglong
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Jianqiu
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Youbing
authors.initials: Y
authors.lastname: Guo
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba 305-8634, Japan.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba 305-8634, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Kadono-Okuda
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Liu
authors.affiliation: Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500001, India.
authors.forename: Kallare P
authors.initials: KP
authors.lastname: Arunkumar
authors.affiliation: Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500001, India.
authors.forename: Javaregowda
authors.initials: J
authors.lastname: Nagaraju
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Shiping
authors.initials: S
authors.lastname: Liu
authors.affiliation: Insect Molecular Genetics and Biotechnology, Institute of Biosciences &Applications, National Centre for Scientific Research "Demokritos", Athens 15310, Greece.
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Labropoulou
authors.affiliation: Insect Molecular Genetics and Biotechnology, Institute of Biosciences &Applications, National Centre for Scientific Research "Demokritos", Athens 15310, Greece.
authors.forename: Luc
authors.initials: L
authors.lastname: Swevers
authors.affiliation: Insect Molecular Genetics and Biotechnology, Institute of Biosciences &Applications, National Centre for Scientific Research "Demokritos", Athens 15310, Greece.
authors.forename: Panagiota
authors.initials: P
authors.lastname: Tsitoura
authors.affiliation: Insect Molecular Genetics and Biotechnology, Institute of Biosciences &Applications, National Centre for Scientific Research "Demokritos", Athens 15310, Greece.
authors.forename: Kostas
authors.initials: K
authors.lastname: Iatrou
authors.affiliation: Indian Institute of Science, Bangalore, India.
authors.forename: Karumathil P
authors.initials: KP
authors.lastname: Gopinathan
authors.affiliation: University of Rhode Island, Kingston 02881, USA.
authors.forename: Marian R
authors.initials: MR
authors.lastname: Goldsmith
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Qingyou
authors.initials: Q
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Chongqing 400716, China.
authors.forename: Kazuei
authors.initials: K
authors.lastname: Mita
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics* / Q000378:metabolism; D002823:Chorion; D019295:Computational Biology / Q000379:methods; D004527:Egg Proteins; D004528:Egg Shell; D020224:Expressed Sequence Tags; D005786:Gene Expression Regulation; D015723:Gene Library; D023061:Gene Order; D059014:High-Throughput Nucleotide Sequencing; D058977:Molecular Sequence Annotation; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D020543:Proteome; D040901:Proteomics / Q000379:methods; D040641:Quantitative Trait Loci; D014158:Transcription, Genetic
chemical_list: D004527:Egg Proteins; D020543:Proteome; C015753:chorion proteins