Structural characterization of the medfly hsp83 gene and functional analysis of its proximal promoter region in vivo by germ-line transformation.
In order to define the regulatory elements responsible for the expression of the medfly hsp83 (Cchsp83) gene, we determined the sequence of a genomic region of the gene that included 3,536 bp upstream of the transcription initiation site, the first untranslated exon of 144 bp, a 275-bp intron, and 516 bp of the second coding exon. Structural analysis of the 5' flanking region revealed the presence of a typical TATA box, 28 bp upstream of the transcription start site, and seven putative heat shock elements (HSEs) further upstream. The 5' untranslated region of the Cchsp83 mRNA was found to contain extensive secondary structure in the first 126 nucleotides. We carried out deletion functional analysis of the proximal promoter region (-380/+139) in vivo by germ line transformation using the lacZ as a reporter gene. We found that sequences in the -380/-86 region are essential for the constitutive expression of the Cchsp83 gene. Under normal conditions, the -380/+139 region was able to drive significant levels of transgene expression in all developmental stages of the medfly as well as in the ovaries and testis. In most stages, the temporal expression pattern of the reporter gene was similar to the respective pattern of the endogenous Cchsp83 gene. Although the -380/+139 promoter region contained two putative HSEs, it was found unable to confer any heat-induced expression in the reporter gene.
Division of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, Patras, Greece.
Maria
M
Theodoraki
Marianthi
M
Tatari
George
G
Chrysanthis
Antigone
A
Zacharopoulou
Anastassios C
AC
Mintzas
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D033622:Ceratitis capitata / Q000166:cytology / Q000235:genetics*; D005854:Germ Cells / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics*; D007763:Lac Operon; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014170:Transformation, Genetic
D006360:Heat-Shock Proteins; D019476:Insect Proteins