Escherichia coli genes expressed preferentially in an aquatic environment

We isolated genomic clones that contain the 5'-flanking region of the mouse activin beta A subunit gene. The nucleotide sequence determination of the 5'-flanking region of the gene and the comparison of that with the reported mouse cDNA structure identified the putative 5' regulatory region, a novel first exon and a part of the first intron of the gene within this region. The putative 5' regulatory region of the mouse activin beta A subunit gene directed the expression of CAT gene in transfected HT1080 cells. Successive deletions of this region demonstrated a 400-bp region that exerts a strong positive effect on promoter activity of the mouse activin beta A subunit gene.