Effect of 5'-flanking sequence deletions on expression of the human insulin gene in transgenic mice
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Expression of the human insulin gene was examined in transgenic mouse lines carrying the gene with various lengths of DNA sequences 5' to the transcription start site (+1). Expression of the transgene was demonstrated by 1) the presence of human C-peptide in urine, 2) the presence of specific transcripts in pancreas, but not in other tissues, 3) the specific immunofluorescence staining of pancreatic islets for human C-peptide, and 4) the synthesis and accumulation of human (pro)insulin in isolated islets. Deletions in the injected DNA fragment of sequences upstream from positions -353, -258, and -168 allowed correct initiation of the transcripts and cell specificity of expression, while quantitative expression gradually decreased. Deletion to -58 completely abolished the expression of the gene. The amount of human product that in mice harboring the longest fragment contributes up to 50% of the total insulin does not alter the normal proportion of mice insulins I and II. These results suggest that expression of the human insulin gene in vivo results from the cooperation of several cis-regulatory elements present in the various deleted fragments. With none of the deletions used, expression of the transgene was observed in cell types other than beta-islet cells.
Original language | English |
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Journal | Molecular endocrinology (Baltimore, Md.) |
Volume | 4 |
Issue number | 5 |
Pages (from-to) | 669-77 |
Number of pages | 9 |
ISSN | 0888-8809 |
Publication status | Published - May 1990 |
- Animals, C-Peptide, Chromosome Deletion, Female, Gene Expression, Humans, Immunohistochemistry, Insulin, Male, Mice, Mice, Transgenic, Pancreas, RNA, Messenger
Research areas
ID: 47974095