Sequence of the human insulin gene.

Area of Science:

• Molecular Biology
• Genetics
• Gene Regulation

Background:

• The human insulin gene plays a crucial role in glucose metabolism.
• Understanding gene structure, including intervening sequences (introns), is key to deciphering gene regulation.
• Previous studies have identified introns in eukaryotic genes, but their specific locations and evolutionary significance vary.

Purpose of the Study:

• To identify and characterize the intervening sequences within the human insulin gene.
• To compare the structure of the human insulin gene with that of the rat insulin gene.
• To infer potential regulatory regions and the ancestral state of the insulin gene.

Main Methods:

• Gene sequence analysis of the human insulin gene.
• Comparative genomic analysis between human and rat insulin genes.
• Identification of transcribed regions and intervening sequences in mRNA.

Main Results:

• The human insulin gene possesses two intervening sequences.
• One intron is located in the 5'-untranslated region of the mRNA.
• The second intron interrupts the C-peptide encoding region of the gene.
• Comparative analysis revealed conserved regions preceding the gene in both human and rat, suggesting regulatory roles.
• The findings indicate that the ancestral insulin gene likely contained two introns.

Conclusions:

• The human insulin gene's intron-exon structure is conserved, with introns in the 5'-untranslated and C-peptide regions.
• The presence of conserved upstream DNA segments points to important regulatory elements controlling insulin gene expression.
• The study supports the hypothesis that the ancestral insulin gene was characterized by the presence of two intervening sequences.