Miguel
Advanced Member
Member # 47
|
posted
Anyone who's feeling particularly evolved this holiday season might take this into consideration: The genome of a mouse is 99 percent similar to a human being's.
Even more disturbing to those who consider themselves a higher form of life than, say, a sprig of mustard, is the fact that the human genome is only 15 percent larger than the mustard plant's.
But for scientists, these facts are thrilling. It means that by comparing various organisms to humans, they can figure out what each of our 30,0000 genes do. And the more similar an organism is to humans, the more they can learn.
"2002 is the year of the rodent," Richard Gibbs, director of the human genome sequencing center at Baylor College of Medicine, wrote in an e-mail. "The mouse was drafted and published -- the rat was drafted and is now being analyzed."
If the same gene is present in humans and the mouse, rat and even a mustard plant, it has surely been preserved throughout evolution for good reasons. That indicates to scientists it's a good gene to study because it probably has an important function. In the field of comparative genomics, researchers aim to discover the secrets of evolution and disease.
When researchers sequence the DNA of a genome, they use a machine like Applied Biosystems ABI Prism 3700 to determine the order of the letters A, T, C and G, which stand for the nucleotides adenine, cytosine, thymine and guanine. The letters form base pairs that link together to form the rungs on the ladder of the DNA double helix.
"(The) mouse enables us to identify many more features in the human genome than we could see by analyzing the human sequence alone," said John McPherson, co-director of the genome sequencing center at Washington University in St. Louis, one of the many labs that contributed to publishing the human genome in 2001.
The mouse genome is also important because it's the most common animal used to test human drugs. Knowing the function of mouse genes can help researchers engineer mice with diseases like epilepsy on which they can test potential therapies.
This year also goes down in history as the year scientists completed the genome of the cute but deadly pufferfish, thanks to the efforts of researchers at the Joint Genome Institute in Walnut Creek, California.
The JGI also sequenced the sea squirt . It might be an unsightly creature, but its embryos are strikingly similar to those of humans, so scientists hope to learn from the early stages of their development. They're also the most primitive animals that have a thyroid gland.
It's remarkable that such an unassuming little creature -- one that Aristotle thought was a plant -- could have so much in common with humans, researchers say. Its genome is already helping researchers discover the processes underlying some human diseases.
At Baylor University, researchers sequenced the genomes of two types of flies in 2002.
"Drosophila melanogaster is a surprisingly good model for human genetics and molecular biology," Baylor's Gibbs said. "Drosophila pseudoobscura is great for finding gene regulatory regions by cross-species comparisons."
In 2003, Baylor researchers will work on the honeybee, the sea urchin and the cow.
"Genomics is really rocking along!" Gibbs said.
Even more exciting to scientists is work being done at sequencing centers around the world on thechimpanzee . Genetically, the chimp is 99.9 percent the same as a human.
Scientists decode the genomes of organisms for other reasons besides learning about humans. They also do it to learn how to make better vaccines against diseases such as malaria or bioweapons like anthrax.
In 2002, scientists completed sequencing the genome of the anthrax bacteriums , as well as the parasite that causes malaria and the mosquito that transmits it.
Studying genomics with the idea of engineering better food for people, scientists have focused on common grains such as rice. The genomes of two types of rice were decoded in 2002. Groups like Greenpeace protest this work because they fear altering the genes in the food humans eat could be harmful.
In 2003, scientists are looking forward not only to sequencing the chimp genome, but also that of the lowly but genetically important chicken.
"The chicken is extremely well-studied for embryogenesis ," Gibbs said, "and is very well-placed in evolution to make comparisons with other vertebrates."
For a full list of completed genomes, see the Genome News Network.
--------------------
Romans 9:11-24
Our Eschatology may vary even our Ecclesiology may be disputed among us but our Soteriology most assume a singularity and exclusivity which in biblical term is known as Quote; "The Narrow Way" and Quote!
Posts: 2792 | From: Stockton,Ca | Registered: Jun 2002
| IP: Logged | 
|
Printer-friendly view of this topic
