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dictyNews Volume 33 Number 08
dictyNews
Electronic Edition
Volume 33, number 8
September 25, 2009
Please submit abstracts of your papers as soon as they have been
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or by using the form at
http://dictybase.org/db/cgi-bin/dictyBase/abstract_submit.
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Announcement:
In del Álamo et al. (2007), PNAS 104 no. 33, 13343-13348 we described an
improved Fourier traction cytometry algorithm that allows the calculation of 2D
traction forces from the 2D deformations of an elastic substrate. We are
making it available as a software package which can be found at
http://maeresearch.ucsd.edu/~jalamo/dynacyte.
Ruedi Meili
=========
Abstracts
=========
Differentiation inducing factors in Dictyostelium discoideum: a novel low
molecular factor functions at an early stage(s) of differentiation
Akiko A. Oohata1*, Masashi Fukuzawa2, Rie Hotta3, Manabu Nakagawa4,
Masatake Niwa3 and Yoshiaki Takaya3
1Biological Laboratory and 4Chemical laboratory, Kansai Medical University,
Hirakata, Osaka 573-1136, Japan
2 Department of Biology, Faculty of Agriculture and Life Science, Hirosaki
University, Hirosaki, Aomori 036-8561, Japan
3 Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468-8503, Japan
Devel. Growth & Differ., in press
There are reports that secreted factor(s) are involved in prespore cell
differentiation in Dictyostelium discoideum, but the structures and functions of
the various factors have not been elucidated. Previously, we described two
prespore cell-inducing factors in conditioned medium; one was a glycoprotein
named prespore-cell inducing factor (ψ factor, or PSI-1), and the other
a heat stable, dialyzable factor(s). In this paper, we purified and characterized
the most potent prespore-cell inducing activity in dialysates. The factor began
to be secreted after the onset of starvation and stopped being secreted once
the cells had aggregated, which was earlier than the onset of psi factor gene
expression. In addition, unlike psi factor, its secretion did not appear to
depend on activation of protein kinase A. Interestingly, the purified factor
not only induced prespore-cell specific genes such as pspA and cotC but
also a prestalk-cell specific gene, ecmB in vitro. The purified factor is
tentatively designated polyketide like factor (PLF), because it seems to be
a novel polyketide with mol wt 208. Half maximal induction of prespore cell
was obtained with 26 nM of PLF. We propose that PLF plays a key role in
the acquisition of differentiation commitment, before the psi factor induces
specifically prespore cell differentiation.
Submitted by Akiko Oohata [oohata@makino.kmu.ac.jp]
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[End dictyNews, volume 33, number 8]
