DC (12/11/98)- Researchers expect big things from the little worm C.elegans,
now that the genome has been sequenced completely. While the genomes of yeast
and bacteria have been sequenced, this is the first time a complete animal
genome has been mapped.
Genome researchers in St. Louis, MO. and Cambridge, England worked together
for eight years to elucidate the genetic blueprint for the lowly worm, a longtime
favorite of geneticists. The instruction set for building the one millimeter
round worm Caenorhabditis elegans is contained in 97 million-base pairs
packed inside six chromosomes. Analysis of the genome found 19,099 protein-coding
genes along with another 800 genes that appear to have other functions. This
itself comes as a surprise, since classical genetics predicted there would
be several times fewer genes.
"This is a tremendously gratifying moment and more of a beginning than an
end. We have provided biologists with a powerful new tool to experiment with
and learn how genomes function. We'll be able to ask-and answer-questions
we could never even think about before," said Robert Waterston, leader of
the St. Louis group.
Previous analyses of partial and complete genomes of various organisms has
shown a remarkable conservation of genes across species. A new comparison
of the genome of the S. cerevisiae yeast with that of the worm showed
that 40 percent of the yeast and 20 percent of the worm sequences code for
highly conserved proteins that carry out biological processes common to both
microorganisms, including DNA and RNA metabolism and protein folding, trafficking
and degradation. This finding give insight into the long-term process of evolution,
suggesting that the genes were present and their functions were already established
in the common ancestor of fungi and animals.
"This study represents an important advance. It shows that we can learn the
function of worm genes from the yeast, and vice versa, which makes it likely
that we can also learn the function of conserved human genes from either of
these organisms," said David Botstein, PhD, Stanford W. Ascherman professor
of genetics at Stanford University School of Medicine and senior author of
the study. "
While C. elegans itself is happy to live in the dirt eating bacteria,
it is related to several worms that parasitize human intestines. The knowledge
gained from mapping the C. elegans genome could also lead to new ways
of preventing and treating the diseases caused by these worms. Researchers
might be able to use C. elegans to develop drugs that target unique
nematode genes, creating new strategies for controlling parasites.
The current genome research was characterized by a philosophy of sharing
information freely. Researchers from around the world were able to access
and contribute to the C.elegans genome database over the Internet.
"The commitment of these groups to make their sequence data available to
the research community right from the start is admirable. It typifies the
spirit of the Human Genome Project and is exactly how we plan to operate our
sequencing program on the human genome and other model organisms," said Francis
Collins, director of the National Human Genome Research Institute.
The research appears in the December 11, 1998 issue of the journal Science.