Project: Research project

Project Details


The long-term goal of the proposed research is to understand the processes
that control differentiation of erythroid cells. The approach is to
analyze the properties of permanent mouse erythroleukemia (MEL) cell lines
that can be induced to undergo terminal erythroid differentiation in cell
culture. A major aim is to study the early events that control the
transition of these cells from proliferating, nondifferentiating tumor
cells to cells that are nontumorigenic and committed to terminal
differentiation. A second aim is to learn how the amounts of globin mRNA
and other specific mRNAs are controlled during terminal erythroid
differentiation. A primary method to be used in these studies is cellular
genetics, including DNA-mediated gene transfer of cloned genes and gene

The cellular oncogene c-myc undergoes dramatic changes in expression in the
period before MEL cells become irreversibly committed to terminal
differentiation. To test the role of c-myc in controlling differentiation,
additional copies of an independently regulated c-myc gene will be
introduced into MEL cells. Further tests of a role for c-myc will be
accomplished by studying changes in c-myc expression when the probability
and kinetics of differentiation are altered. C-myc gene transcription and
mRNA stability will be measured to learn how rapid changes in expression

Differentiating MEL cells appear to utilize both transcriptional and
post-transcriptional mechanisms to control the levels of specific mRNAs.
To identify cis-acting DNA sequences and diffusible protein factors that
regulate globin gene transcription, cloned globin genes will be introduced
into MEL cells and their expression will be studied during induced
differentiation. The isolation of mutant MEL cells with defects in
transcriptional control factors also will be undertaken. To investigate
post-transcriptional control of mRNA production, the base sequences in mRNA
that control its turnover will be studied. The sequences will be
identified by constructing and introducing into cells gene chimeras between
two genes whose transcripts differ in stability. This method will then be
applied to specific mRNAs that have different stabilities in terminally
differentiating MEL cells. (M)
Effective start/end date12/31/894/30/04


  • Genetics
  • Molecular Biology
  • Cell Biology
  • Medicine(all)


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