Negative regulation of Ig gene rearrangement by a 150-bp transcriptional silencer.
We previously showed that the V-J intervening sequence of the chicken lambda immunoglobulin locus contains a strong silencer that acts both on transcription and rearrangement. We show here that the transcriptional silencer activity can be ascribed to a minimal 150-bp fragment. The rearrangement silencing activity was previously shown by the replacement of the V-J intervening sequence with a neutral DNA fragment that dramatically increased the rate of rearrangement of the transgene. Insertion of the minimal silencer in this neutral fragment is shown here to result in a marked decrease in rearrangement of the transgenic construct. Strikingly, deletion of 28 bp from the 150-bp fragment abolished most of the transcriptional silencing activity and had a similar effect on rearrangement. These results conclusively correlate the silencing activity on both rearrangement and transcription.
Cocea
L
L
INSERM, Unité 373, Faculté de Médecine Necker, Paris, France. cocea@necker.fr
Dahan
A
A
Ferradini
L
L
Reynaud
C A
CA
Weill
J C
JC
D000818:Animals; D002645:Chickens; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D007146:Immunoglobulin lambda-Chains / Q000235:genetics*; D008969:Molecular Sequence Data; D014158:Transcription, Genetic / Q000276:immunology*
D007146:Immunoglobulin lambda-Chains