During B-cell differentiation enhancer activity and transcription rate of immunoglobulin heavy chain genes are high before mRNA accumulation.
During differentiation of B lymphocytes, a low level of immunoglobulin heavy chain gene transcripts is apparent at the pre-B-cell stage, and a dramatic increase in immunoglobulin mRNA level is seen after stimulated B cells have matured into immunoglobulin-secreting plasma cells. We have measured the transcription rate of endogenous heavy chain genes using cell lines representative of various stages of murine B-lymphocyte differentiation. We observe a good correlation between RNA polymerase density, as determined by nuclear run-on transcription experiments, and the activity of the heavy chain gene enhancer, as assayed by transfection experiments. Both enhancer activity and heavy chain gene transcription are very high in pre-B-cell lines. Thus we conclude that the increased accumulation of immunoglobulin heavy chain mRNA in immunoglobulin-secreting plasma cells is regulated mainly by posttranscriptional processes.
Gerster
T
T
Picard
D
D
Schaffner
W
W
D000199:Actins / Q000235:genetics; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000502:physiology*; D002454:Cell Differentiation; D002460:Cell Line; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D005809:Genes, Regulator; D006649:Histocompatibility Antigens / Q000235:genetics; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D051379:Mice; D010950:Plasma Cells / Q000502:physiology; D011401:Promoter Regions, Genetic; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism; D014158:Transcription, Genetic
D000199:Actins; D006649:Histocompatibility Antigens; D007143:Immunoglobulin Heavy Chains; D012333:RNA, Messenger