Sunday, November 27, 2005

Silenced gene in worm shows role in regeneration

Silenced gene in worm shows role in regeneration: "Silenced gene in worm shows role in regeneration
When smedwi-2 gene is silenced, regeneration stopped in planarians
SALT LAKE CITY -- Researchers at the University of Utah have discovered that when a gene called smedwi-2 is silenced in the adult stem cells of planarians, the quarter-inch long worm is unable to carry out a biological process that has mystified scientists for centuries: regeneration.

[...]

The study follows a landmark work that he and Reddien published last spring in Developmental Cell, in which, using a method of gene silencing called RNA interference (RNAi), the researchers silenced more than 1,000 planarian genes, some of which they identified as essential for regeneration. The Science study focus on one such gene, smedwi-2, and brings a new level of genetic detail to understanding planarian regeneration.

Planarians long have fascinated biologists with their ability to regenerate. A worm sliced in two forms two new worm s; even a fractional part of a planarian will grow into a new worm. Scientists know that planarian stem cells, called neoblasts, are central to regeneration, but their exact role is only now being learned.

When an animal stem cell divides, two daughter cells are formed: one that is another stem cell and a second one that can differentiate into the cells that form bone, tissue, and other parts of an organism. These second types of cells are essential for regeneration or maintaining the form and function of tissues by replacing cells that die, a process called homeostasis.

By eliminating smedwi-2, the researchers uncovered a role of this protein in regulating the normal differentiation and function of daughter cells. "

No comments: