Premium
Structure of the Bombyx sorbitol dehydrogenase gene: a possible alternative use of the promoter
Author(s) -
Niimi T.,
Yamaahlta O.,
Yaginuma T.
Publication year - 1996
Publication title -
insect molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.955
H-Index - 93
eISSN - 1365-2583
pISSN - 0962-1075
DOI - 10.1111/j.1365-2583.1996.tb00101.x
Subject(s) - biology , bombyx mori , gene , bombyx , microbiology and biotechnology , promoter , sorbitol dehydrogenase , exon , genetics , intron , polyadenylation , transcription (linguistics) , gene expression , sorbitol , biochemistry , linguistics , philosophy
In an Initial effort to understand the molecular mechanism of how low temperature induces sorbitol dehydrogenase gene expression in diapause eggs of the silkworm, the sorbitol dehydrogenase gene was isolafed from a Bombyx genomic library using a cDNA encoding the Bombyx homologue of mammalian sorbitol dehydrogenase as a probe. The gene extended for about 10 kb, consisting of eight exons and seven introns. Four TATA motifs were found In the 5′ upstream region of the gene, without CCAAT. AATTAA, instead of AATAAA, was localized in the upstream region of the polyadenylation site. Although a single copy of this gene was present per haploid genome, 1.2 kb and 1.1 kb transcripts were found from yolk cells in diapause eggs and from larval fat‐body cells, respectively. The two major transcription initiation sites corresponding to both transcripts were localized at 355 and 226 base pairs upstream from the translation start she, indicating an alternative use of promoter. The 5′‐upstream region of the gene contained a consensus sequence, TGA(A/T)AA(A/GIT), that has been found in insect genes expressed mainly in larval and pupal fat bodies. It also contained three kinds of sequences similar to cis‐elements recognized by members of the steroid receptor superfamily, such as chicken ovalbumin upstream promoter transcription factor (COUP‐TF)/ Drosophila Seven up (SVP), Drosophila hormone receptor 39 (DHR39) and Bombyx fushi tarazu transcriptional factor 1 (BmFTZ‐F1).