From csbi-events at mit.edu  Fri May 16 15:51:11 2008
From: csbi-events at mit.edu (CSBi events)
Date: Fri, 16 May 2008 15:51:11 -0400
Subject: [CSBi-events] SAVE THE DATE: May 23rd - CSBi seminar
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Spring 2008 Seminar Series on Computational and Systems Biology
*This is the final seminar for the spring semester.*
 
Friday, May 23, 2008
3:00 pm - 4:00 pm
*Room 68-181

Presenting:
Professor Eric Davidson
California Institute of Technology
Division of Biology
 

Title: "System Level Genomic Regulatory Logic: Gene Network for Sea Urchin
Development"

 
Abstract: If the premise of system biology is correct then causal
explanations of biological phenomena should emerge from system level
analyses if they approach completeness in respect to the functional linkages
among the parts of the model. The developmental GRN controlling development
of the skeletogenic micromere lineage of the sea urchin embryo now includes
experimentally established, causal transcriptional links to every regulatory
gene expressed specifically in this lineage. It provides the opportunity to
challenge directly this argument. We show that at its current level of
maturity GRN structure provides an explanation, in terms of the topology of
its genomically encoded subcircuits, of why all of the functions this
lineage executes occur. These functions are: transformation of the initial
maternal cues localized in the micromeres into an initial transcriptional
regulatory state; activation of downstream genes through a double negative
transcriptional gate; presentation of inductive signals to adjacent cells;
dynamic lockdown of the definitive transcriptional regulatory state;
specific activation of skeletogenic differentiation gene batteries;
exclusion of alternative regulatory states. This progression of
developmental functions can be considered as a series of logic operations
and the dynamics of the system also fall, out from GRN structure. Additional
GRN circuitry controls a dynamic concentric wave of gene expression
beginning in the skeletogenic micromere lineage and sweeping outward across
the mesodermal and endodermal domains. The GRN provides a new way to
understand evolution as well as development. For example, the skeletogenic
function of the micromere lineage is a derived feature of modern echinoderms
that probably arose in the Triassic <250 mya. By mapping onto the topology
of the GRN the genes expressed and not expressed in adult skeletogenic
centers, we can discern the regulatory linkages that had to be formulated in
order to co-opt skeletogenic genetic function to the micromere embryological
address. This idea is subject to experimental test.

 
*NOTE: Location change - this talk will be held at building 68, room 181.
Light refreshments to be served at 2:45 pm
Host: Alexander van Oudenaarden, Department of Physics

 
PLEASE POST THE ATTACHED ANNOUNCMENT IN THE AREA.
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From csbi-events at mit.edu  Thu May 22 20:21:21 2008
From: csbi-events at mit.edu (CSBi events)
Date: Thu, 22 May 2008 20:21:21 -0400
Subject: [CSBi-events] Eric Davidson's CBSi seminar cancelled - Friday May
	23rd
References: <003801c89fdb$47b64180$e4005212@DB3GWSC1>
	<000601c8b78e$3173a280$e4005212@DB3GWSC1>
Message-ID: <00a301c8bc6a$ee110ff0$6b01a8c0@AvO>

Unfortunately we have to cancel Eric Davidson's CSBi seminar this Friday May 
23rd because of travel delays. We will try to reschedule his seminar for a 
next semester.