Bar Harbor, Maine--With names like Snail and Slug, you might expect genes belonging to the category known as the Snail family to be associated with some steady, slow-moving biological progression. Instead, these genes help direct the dynamic, fast-paced race of early embryonic development, when cells are dividing, migrating around the body and differentiating into the millions, even trillions, of specialized cells that constitute a mature organism.
Snail family genes are present in vertebrates and have counterparts in invertebrates such as the fruit fly Drosophila. To biologists, this means that these genes are "well conserved across species"--in other words, diverse species retained them as they evolved. So it's reasonable to expect that their function would be the same among all vertebrates: mice as well as frogs and birds, for instance.
In a paper just released in the Proceedings of the National Academy of Sciences, two Jackson Laboratory scientists have demonstrated both a confirmation of the consistent role of Snail genes in vertebrates, and a surprising exception.
Dr. Thomas Gridley and Dr. Steven Murray showed that Snail family genes operate consistently in mice and birds in controlling the acquisition of differences between the two sides of the body. While the body plan of all vertebrates is overtly symmetric on both body sides, most internal organs exhibit an asymmetric distribution. For example, in mammals the heart is located on the left side of the body while the liver is on the right. Gridley and Murray found that, similarly to what has been described for birds, the Snail gene controls acquisition of these asymmetric body differences in mice.
On the other hand, Gridley and Murray found that Snail family gene function relating to neural crest cells is different in mice. Neural crest cells are developmental cells that form at the border of the embryonic neural plate (a structure that later develops into the spina
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Contact: Mark Wanner
mark.wanner@jax.org
207-288-6051
Jackson Laboratory
26-Jun-2006