Functional analysis of defined mutations in the immunoglobulin heavy-chain enhancer in transgenic mice.
We have analyzed the effect of defined mutations in the mouse immunoglobulin heavy-chain enhancer after introduction into the germline of transgenic mice. We have tested a mutation of the enhancer octamer motif, a double mutation of the octamer motif and the microB-site, and a triple mutation in the microE2, microE3 and microE4-sites. All constructs are expressed in the spleen of transgenic mice. Furthermore, expression is exclusively detectable in lymphoid organs and not in several nonlymphoid tissues. Whereas mutations in the microE-sites have a more pronounced effect on transgene activity in thymocytes as compared to bone marrow and spleen cells, the octamer/microB double mutation shows significantly reduced expression levels only in B-cells. Finally, our results demonstrate that the intronic heavy-chain enhancer element does not contribute to the increase steady state levels of heavy-chain mRNA after stimulation of spleen cells with LPS.
Annweiler
A
A
Zentrum für Molekulare Biologie Heidelberg, Germany.
Müller
U
U
Wirth
T
T
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics*; D005803:Genes, Immunoglobulin; D005914:Globins / Q000235:genetics; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D007148:Immunoglobulin mu-Chains / Q000235:genetics*; D007438:Introns / Q000235:genetics; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D013154:Spleen / Q000166:cytology
D007148:Immunoglobulin mu-Chains; D005914:Globins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases