Upgrade subject to access all content
Despite being present in all cells, the Immunoglobulin (Ig) genes, which encode antibodies, are only expressed in B-cell lineages.
The best explanation for this observation is
MicroRNAs that specifically target Ig mRNAs for destruction are produced in all cells except B cells.
Cyclin-dependent kinases prevent the initiation of Ig gene transcription in all cells except B cells.
The Ig gene promoter regions have conserved sequences that bind transcription factors unique to B cells.
The cytokine interferon (IFN) signals specifically and only to B cells to activate Ig gene expression.