Gidi Shemer
Postdoc
Molecular and Cellular
dissection
of cell-cell adhesion during early embryogenesis in C. elegans
Cell-cell adhesion is a key
process in development and disease.
Starting at early embryogenesis combined functions of cell adhesion
molecules (CAMs) mediate stable and dynamic adhesions in a variety of
cells. C. elegans is an excellent model to study such adhesion events as
worm embryos show dynamic adhesions already at the 4-cell stage and
this organism is almost unique among genetic model systems in that we
can readily isolate specific cells and test them for cell adhesion
directly.
To date very little is known in C.
elegans about the identity of CAMs that function in early
embryogenesis. I have taken a reverse genetic approach and established
a set of assays to screen candidate adhesion proteins for redundant functions during these stages.To
tackle redundancy I injected worms with pools of multiple
dsRNAs, specific for candidate adhesion proteins. This screen led to
the identification of novel roles for such proteins at the onset of
gastrulation. We found that at the 26-cells stage the
endodermal precursors fail to ingress to the interior of the
embryo when specific adhesion proteins are being knocked down by RNAi.
My long term goal is to study
how dynamic adhesions between cells contribute to proper development in
early embryogenesis. I plan to identify
cell adhesion proteins that function during these stages and to use
assays developed in my preliminary work to explore the mechanisms by
which these adhesion proteins act.
| Papers from Gidi's
previous work on cell
fusion:
Podbilewicz B, Leikina E,
Sapir A, Valansi C, Suissa M, Shemer
G, Chernomordik LV. The C.
elegans developmental fusogen EFF-1 mediates homotypic fusion in
heterologous cells and in vivo (2006). Dev Cell. 11:471-81.
Cassata G., Shemer G., Morandi
P., Donhauser R., Podbilewicz B.,
Baumeister R. ceh-16/engrailed compartmentalizes the epidermis of the
roundworm Caenorhabditis elegans (2005). Development 132:739-49.
*Shemer G.,
*Suissa M.,
Kolotuev I., Nguyen K.C.Q., Hall D.H.,
Podbilewicz B. EFF-1 is sufficient to initiate and execute
tissue-specific cell fusion in C. elegans (2004). Curr. Biol.
14:1587-1591.
Shemer G. and
Podbilewicz B. The story of cell fusion: big lessons from little worms
(2003). BioEssays. 25:672-682. Review
Shemer G. and
Podbilewicz B. LIN-39/Hox triggers cell division and
represses EFF-1/Fusogen- dependent vulval cell fusion (2002).
Genes&Development 16:3136-3141.
*Mohler W.A., *Shemer G., del
Campo J.J., Valansi C., Opoku-Serebuoh
E., Scranton V., Assaf N., White J.G., Podbilewicz B. The type I
membrane protein EFF-1 is essential for developmental cell fusion
(2002). Dev. Cell. 2:355-62.
Shemer G. and
Podbilewicz B. Fusomorphogenesis: cell fusion in organ formation
(2000). Dev. Dyn. 218:30-51. Review
Shemer G.,
Kishore R.
and Podbilewicz B. Ring formation drives
invagination of the vulva in C. elegans: Ras, cell fusion and cell
migration determine structural fates (2000). Dev. Biol. 221:233-248.
[*These authors contributed equally to this work]
|
Talks:
Cadherin-catenin complex proteins regulate
cell movements during C. elegans gastrulation independently of adherens
junctions. Santa Cruz Developmental Biology Meeting, June 2008.
As sticky as can get: Cell adhesion during embryogenesis in C.
elegans. 16th International C.
elegans meeting, UCLA, June 2007.
Starting to unravel the enigma of cell fusion. 15th International C.
elegans meeting, UCLA, June 2005.
To fuse or not to fuse: a fundamental question. Invited lecture, FISEB,
Ilanit conference, Eilat. February 2005
Eff for fusion: mechanism and regulation of the fusion machinery in C.
elegans. Invited lecture, NIH, June 2004.
EFF - you’re fused, Engrailed - you’re not. Regulation of the fusion
machinery in C. elegans. Worm and Fly meeting. Hebrew University,
Jerusalem. February 2004.
The Hox gene lin-39/Dfd inhibits cell fusion by repressing the
fusogenic activity of eff-1. Worm and Fly meeting. Hebrew University,
Jerusalem. February 2002.
HOW HOX WORKS? eff-1 is the name, effector of cell fusion is the game.
13th International C. elegans meeting, UCLA, June 2001.
Who said you need two to tango? The development of the real and pseudo
vulvae of a let-60 gf mutant. 12th International C. elegans meeting,
University of Wisconsin-Madison, June 1999.
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