Effect of 5'-flanking sequence deletions on expression of the human insulin gene in transgenic mice

TY - JOUR

T1 - Effect of 5'-flanking sequence deletions on expression of the human insulin gene in transgenic mice

AU - Fromont-Racine, M

AU - Bucchini, D

AU - Madsen, O

AU - Desbois, P

AU - Linde, S

AU - Saulnier, C

AU - Ripoche, M A

AU - Jami, J

AU - Pictet, R

AU - Nielsen, Jens Høiriis

PY - 1990/5

Y1 - 1990/5

N2 - 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.

AB - 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.

KW - Animals

KW - C-Peptide

KW - Chromosome Deletion

KW - Female

KW - Gene Expression

KW - Humans

KW - Immunohistochemistry

KW - Insulin

KW - Male

KW - Mice

KW - Mice, Transgenic

KW - Pancreas

KW - RNA, Messenger

M3 - Journal article

C2 - 2274051

SN - 0888-8809

VL - 4

SP - 669

EP - 677

JO - Molecular endocrinology (Baltimore, Md.)

JF - Molecular endocrinology (Baltimore, Md.)

IS - 5

ER -