Mechanisms of Cellular Development in Maya Pines' Learning from the Worm
Maya Pines' Learning from the Worm is highly informative and well written. In short, the article confronts the mystery behind the mechanisms that operates during cellular development. Scientists were divided over the type of mechanism that is used to determine a cell's fate, whether the cell would develop into a nerve, muscle, sex, or somatic cells. Two theories surfaced: if whether a cell's fate is intrinsic or cell-interactive. Some scientists refer to these two theories as European or American plan of development. The European plan of development pertains to the idea that a cell's fate is determined by their ancestry whereas the American plan of development, a cell's fate is determined by outside environment and position.
The little round worm known as C. elegans was used as a basis for the experiments. This was an excellent choice because not only did the worm have a short life span, reaching sexual maturity in 3 days, but also because the worm is a hermaphrodite. The fact that the worm was a hermaphrodite proved to be an incredible advantage. The worm was able to self fertilize; making it possible for mutants that would otherwise die out without breeding to propagate. Also, the worm was transparent which allowed the scientists to view the developments of each individual cell and the role that they play. Thousands of these tiny worms can fit into a petri dish where they can be viewed for recombinations and mutations.
An English scientist, John Sulston studied the C. Elegans, using a light microscope equipped with Nomarski contrast optics to trace the worm's cells as the animal developed, tracing the history of every cell. Although this was an effective way of studying the worm, other scientists sliced the worm from nose to end, and analyzing the worm under an electron microscope. Through these techniques, scientists have been able to obtain first-time information on the rules of development at the single cell level. This information provides the foundation for future experiments with the worm, trying to determine how a cell's fate is decided.
In experimenting with the reproductive properties of the worm, scientist, Sternberg and Horvitz stumbled across a series of 3 genes, which are related to human cancer. Using the knowledge that they've obtained through experimentation, the scientists set about trying to determine what molecules took part in determining which cells become the vulva tissues and which become skin. They began by distinguishing the mutant worms, which was not a difficult task to undertake. The mutant worms were defective in egg laying because they had no vulva in which to expel the eggs. But because the worms were hermaphrodites, self-fertilization occurred, where the eggs internally developed and hatched within the worm's body, eventually consuming the parent's body. Scientists were able to...