new TR: development

[Eric Mjolsness]

          ***** Please do not distribute to other lists *****

The following technical report is now available:

		"A Connectionist Model of Development"

by Eric Mjolsness (1), David H. Sharp (2), and John Reinitz (3)
    (1) Department of Computer Science, Yale University
    (2) Theoretical Division, Los Alamos National Laboratory
    (3) Department of Biological Sciences, Columbia University

Abstract:

We present a phenomenological modeling framework for development.
Our purpose is to provide a systematic method for discovering
and expressing correlations in experimental data on gene expression
and other developmental processes.  The modeling framework is based
on a connectionist or ``neural net'' dynamics for biochemical
regulators, coupled to ``grammatical rules'' which describe certain
features of the birth, growth, and death of cells, synapses and other
biological entities.  We outline how spatial geometry can be included,
although this part of the model is not complete.  As an example of the
application of our results to a specific biological system, we show
in detail how to derive a rigorously testable model of the network of
segmentation genes operating in the blastoderm of Drosophila.
To further illustrate our methods, we sketch how they could be applied
to two other important developmental processes: cell cycle control and
cell-cell induction.  We also present a simple biochemical model
leading to our assumed connectionist dynamics which shows that the
dynamics used is at least compatible with known chemical mechanisms.

For copies of YALEU/DCS/RR-796, please send email to

	shanahan-mary at cs.yale.edu

or physical mail to

	Eric Mjolsness
	Yale Computer Science Department
	P.O. Box 2158 Yale Station
	New Haven CT 06520-2158

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