Structure of the growth hormone-encoding gene and its promoter in mice

The isolation and nucleotide sequence determination of the 5' flanking region of the mouse growth hormone (mGH)-encoding gene (mGH) is described. The mGH gene consists of five exons and four introns, as is observed in other mammalian species. The second intron in mGH is much smaller than its rat counterpart, thus being similar in size to human, bovine and porcine GH. The transcription start point was determined to be a C residue 62 bp upstream from the start codon, ATG. Analysis of 1767 bp of the 5' flanking region, with respect to putative regulatory elements, revealed a TATA box, two binding sites for growth hormone factor (GHF1), a GC box (SP1), a thyroid-response element (TRE) and a silencer (SiL) sequence motif. As expected, the mGH promoter shows a higher degree of homology with rat, as compared to the other mammalian species like pig, cattle and human, where an overall homology exists only at the proximal promoter region.