title: The 62-kb upstream region of Bombyx mori fibroin heavy chain gene is clustered of repetitive elements and candidate matrix association regions.
abstract: We sequenced an 80 kb DNA region containing the complete sequence of the silkworm Bombyx mori fibroin gene and its flanking, especially the upstream, regions (-62 kb). About 30% of the 62 kb upstream region is composed of repetitive elements including short interspersed elements Bm1, long interspersed elements L1Bm and mariner-like elements Bmmar1 which are widespread over the silkworm genome. This 62 kb region is also enriched of commonly considered matrix association region (MAR) motifs. A total of 25 individual MAR recognition signatures (MRSs) were identified, with 24 at the upstream and one at the downstream region. Combining two newly developed MAR prediction programs (MAR-finder and Chrclass), ten candidate MARs were predicted, with five containing MRS and seven related to the repetitive elements. The wide distribution of nested repetitive elements, candidate MARs, DNase I hypersensitive sites and other potential regulatory factors recognition sites indicates this region is probably a unique huge cis-acting element contributing to the regulation of the spatial and temporal specificity and efficiency of fibroin gene expression.
authors.affiliation: Institut de Génétique et Microbiologie, Université Paris-Sud et CNRS, 91405 Orsay, France. zhoucongzhao@yahoo.fr
authors.forename: Cong-Zhao
authors.initials: CZ
authors.lastname: Zhou
authors.forename: Fabrice
authors.initials: F
authors.lastname: Confalonieri
authors.forename: Catherine
authors.initials: C
authors.lastname: Esnault
authors.forename: Yvan
authors.initials: Y
authors.lastname: Zivanovic
authors.forename: Michel
authors.initials: M
authors.lastname: Jacquet
authors.forename: Joel
authors.initials: J
authors.lastname: Janin
authors.forename: Roland
authors.initials: R
authors.lastname: Perasso
authors.forename: Zhen-Gang
authors.initials: ZG
authors.lastname: Li
authors.forename: Michel
authors.initials: M
authors.lastname: Duguet
mesh_terms: D024506:5' Flanking Region / Q000235:genetics*; D000818:Animals; D001482:Base Composition; D001665:Binding Sites / Q000235:genetics; D012831:Bombyx / Q000235:genetics*; D005349:Fibroins / Q000235:genetics* / Q000378:metabolism; D015530:Nuclear Matrix / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*
chemical_list: D005349:Fibroins