CSM News
Electronic Edition
Volume 5, number 7
Sept. 2, 1995

Please submit abstracts of your papers as soon as they have been
accepted for publication by sending them to CSM-News@worms.cmsbio.nwu.edu.

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information is available by anonymous ftp from worms.cmsbio.nwu.edu
[165.124.233.50], via Gopher at the same address, or by World Wide Web
at the URL "http://worms.cmsbio.nwu.edu/dicty.html"

===========
 Abstracts
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Calcium and cell-type-specific gene expression in Dictyostelium

Katalin Pinter and Julian Gross

Department of Biochemistry, University of Oxford, South Parks Road,
Oxford OX1 3QU

Differentiation, in press

ABSTRACT

   We have investigated the possible involvement of Ca(2+) in
cell-type-specific gene expression in Dictyostelium
discoideum. Aggregates dissociated and shaken in suspension in buffer
containing EGTA for two hours showed a sharp decline in
prespore-specific transcript levels and failed to accumulate
significant levels of prestalk-specific transcripts. Addition of
either cAMP or Ca(2+) to the suspensions increased the levels of both
classes of transcripts. The two agents may act synergistically, and
nuclear run-on experiments indicated that they stimulated gene
transcription.  Depletion of Ca(2+) stores with the ionophore A23187
in the presence of EGTA prevented expression of all cell-type-specific
genes examined, and the magnitude of the effect was similar for
prespore and prestalk-specific transcripts. We conclude that Ca(2+)
plays a role in gene expression in both prespore and prestalk
cells. It may be involved in post-aggregative gene expression but its
effect does not appear to be cell-type specific.

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[End CSM News, volume 6, number 7]