August 11, 2005

Worm Studies Give Researchers New Perspective on Embryo Formation

How does a multi-cellular organism with specialized organs and tissues develop from a single cell? A team of genomics researchers has moved closer to answering this question by creating the first comprehensive diagram of the molecular interactions that orchestrate early embryo development.

The work--a collaborative effort by scientists from New York University (NYU), Harvard University, the Max Planck Institute and Cenix BioScience in Dresden, Germany--appears in the Aug. 11 issue of the journal Nature.

The team examined the first two cell divisions of Caenorhabditis elegans--a small, transparent, soil-dwelling roundworm widely used as a model organism for studying embryo development and the first animal to have its entire genome sequenced. They used a new approach to combine information from several large-scale, genomics studies on the functions and activity profiles of C. elegans genes and proteins. From their efforts emerged a detailed view of the molecular interaction networks that drive early embryo development.

"The earliest stages of embryo development are important to study because they set up the framework for all subsequent development in that animal," said Kris Gunsalus, NYU researcher and a lead author of the study. By the first cell division, the conditions that influence the worm's specialized tissue and organ development and dictate its body plan have already been established. "The integrated picture we generated in this work provides a 'first draft' molecular map of early embryo development from a global, system-wide perspective."

Their map suggests that a small number of protein groups or clusters--dubbed "molecular machines" by the researchers--coordinates proper embryo development in the worm. The observed "clustering" patterns suggested potential roles for several unstudied genes--information that was not obvious from the original, individual studies. Subsequent experiments confirmed these functions and demonstrated the predictive power of their approach.

C. elegans contains many of the genes and proteins found in more complex organisms--including humans--so these results will help scientists understand more about the universal aspects of development.

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