dictyNews
Electronic Edition
Volume 34, number 16
May 28, 2010

Please submit abstracts of your papers as soon as they have been
accepted for publication by sending them to [log in to unmask]
or by using the form at
http://dictybase.org/db/cgi-bin/dictyBase/abstract_submit.

Back issues of dictyNews, the Dicty Reference database and other
useful information is available at dictyBase - http://dictybase.org.

Follow dictyBase on twitter:
http://twitter.com/dictybase

=========
Abstracts
=========


Dictyostelium amoebae and neutrophils can swim

by Nicholas P. Barry and Mark S. Bretscher

MRC Laboratory of Molecular Biology, Hills Road, Cambridge
CB2 0QH, England


PNAS, in press

Animal cells migrating over a substratum crawl in amoeboid fashion;
how the force against the substratum is achieved remains uncertain.
We find that amoebae and neutrophils, cells traditionally used to study
cell migration on a solid surface, move towards a chemotactic source
whilst suspended in solution. They can swim and do so with speeds
similar to those on a solid substrate. Based on the surprisingly rapidly
changing shape of amoebae as they swim and earlier theoretical
schemes for how suspended microorganisms can migrate
(Purcell EM (1977) Life at low Reynolds number. Am. J. Phys. 45:3-11),
we suggest the general features these cells employ to gain traction with
the medium. This requires either the movement of the cell’s surface from
the cell’s front towards its rear, or protrusions which move down the  
length
of the elongated cell. Our results indicate that a solid substratum is  
not a
prerequisite for these cells to produce a forward thrust during movement
and suggest that crawling and swimming are similar processes, a
comparison we think is helpful in understanding how cells migrate.


Submitted by  Mark Bretscher [[log in to unmask]]
--------------------------------------------------------------------------------


Autophagy in Dictyostelium: genes and pathways, cell death and infection

Javier Calvo-Garrido, Sergio Carilla-Latorre, Yuzuru Kubohara, Natalia
Santos-Rodrigo, Ana Mesquita, Thierry Soldati, Pierre Golstein  and
Ricardo Escalante


Autophagy, in press

The use of simple organisms to understand the molecular and cellular
function of complex processes is instrumental for the rapid development
of biomedical research. A remarkable example has been the discovery in
S. cerevisiae of a group of proteins involved in the pathways of  
autophagy.
Orthologues of these proteins have been identified in humans and
experimental model organisms. Interestingly, some mammalian autophagy
proteins do not seem to have homologues in yeast but are present in
Dictyostelium, a social amoeba with two distinctive life styles, a  
unicellular
stage in nutrient-rich conditions that differentiates upon starvation  
into a
multicellular stage that depends on autophagy. This review focuses on
the identification and annotation of the putative Dictyostelium  
autophagy
genes and on the role of autophagy in development, cell death and
infection by bacterial pathogens.


Submitted by Ricardo Escalante [[log in to unmask]]
==============================================================
[End dictyNews, volume 34, number 16]