The 62-kb upstream region of Bombyx mori fibroin heavy chain gene is clustered of repetitive elements and candidate matrix association regions.
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.
Zhou
Cong-Zhao
CZ
Institut de Génétique et Microbiologie, Université Paris-Sud et CNRS, 91405 Orsay, France. zhoucongzhao@yahoo.fr
Confalonieri
Fabrice
F
Esnault
Catherine
C
Zivanovic
Yvan
Y
Jacquet
Michel
M
Janin
Joel
J
Perasso
Roland
R
Li
Zhen-Gang
ZG
Duguet
Michel
M
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*
D005349:Fibroins