Featured Research

from universities, journals, and other organizations

Two Worms Are Better Than One

Date:
November 17, 2003
Source:
Public Library Of Science
Summary:
With the publication of a genome sequence of C. elegans' first cousin, C. briggsae, Lincoln Stein and colleagues have greatly enhanced biologists' ability to mine C. elegans for biological gold.

Caenorhabditis elegans, a 1-mm soil-dwelling roundworm with 959 cells, may be the best-understood multicellular organism on the planet. As the most "pared-down" animal that shares essential features of human biology from embryogenesis to aging C. elegans is a favorite subject for studying how genes control these processes. The way these genes work in worms helps scientists understand how diseases like cancer and Alzheimer's develop in humans when genes malfunction. With the publication of a genome sequence of C. elegans' first cousin, C. briggsae, Lincoln Stein and colleagues have greatly enhanced biologists' ability to mine C. elegans for biological gold.

Related Articles


After confirming the accuracy of the sequence (it covers 98% of the genome and has an accuracy of 99.98%), the researchers turned to the substance of the genome. Examining the two worm genomes side by side, scientists can quickly spot genes and flag interesting regions for further investigation. Analyzing the organization of the two genomes, Stein et al. not only found strong evidence for roughly 1,300 new C. elegans genes, but also indications that certain regions could be "footprints of unknown functional elements." While both worms have roughly the same number of genes (about 19,000), the C. briggsae genome has more repeated sequences, making its genome slightly larger. The size is estimated to be just over 100 million base pairs, about 1/30 the size of the human genome.

Because the worms set out on separate evolutionary paths about the same time mice and humans parted ways--about 100 million years ago, compared to 75 million years ago--the authors could compare how the two worm genomes have diverged with the divergence between mice and humans. The worms' genomes, it seems, are evolving faster than their mammalian counterparts, based on the change in the size of the protein families (C. elegans has more chemosensory proteins than C. briggsae, for example), the rate of chromosomal rearrangements, and the rate at which silent mutations (DNA changes with no functional effect) accumulate in the genome. This would be expected, the researchers point out, because generations per year are a better measure of evolutionary rate than years themselves. (Generations in worms are about three days; in mice, about three months.)

What is surprising, they say, is that despite these genomic differences, the worms look nearly identical and occupy similar ecological niches; this is obviously not the case with humans and mice, which nevertheless have remarkably similar genomes. It's the quality, rather than the quantity of the changes in the genome, that's important. The nature of these changes, along with many other issues, can now be explored by searching the two species' genomes and comparing those elements that have been conserved with those that have changed.

With the C. briggsae genome sequence in hand, worm biologists have a powerful new research tool. By comparing the genetic makeup of the two species, C. elegans researchers can refine their knowledge of this tiny human stand-in, fill in gaps about gene identity and function, as well as illuminate those functional elements that are harder to find, and study the nature and path of genome evolution.

###

research article: http://www.plos.org/downloads/plbi-01-02-stein.pdf


Story Source:

The above story is based on materials provided by Public Library Of Science. Note: Materials may be edited for content and length.


Cite This Page:

Public Library Of Science. "Two Worms Are Better Than One." ScienceDaily. ScienceDaily, 17 November 2003. <www.sciencedaily.com/releases/2003/11/031117073759.htm>.
Public Library Of Science. (2003, November 17). Two Worms Are Better Than One. ScienceDaily. Retrieved March 27, 2015 from www.sciencedaily.com/releases/2003/11/031117073759.htm
Public Library Of Science. "Two Worms Are Better Than One." ScienceDaily. www.sciencedaily.com/releases/2003/11/031117073759.htm (accessed March 27, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, March 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Lioness Has Rare Five-Cub Litter

Raw: Lioness Has Rare Five-Cub Litter

AP (Mar. 27, 2015) — A lioness in Pakistan has given birth to five cubs, twice the usual size of a litter. Queen gave birth to two other cubs just nine months ago. (March 27) Video provided by AP
Powered by NewsLook.com
Jockey Motion Tracking Reveals Racing Prowess

Jockey Motion Tracking Reveals Racing Prowess

Reuters - Innovations Video Online (Mar. 26, 2015) — Using motion tracking technology, researchers from the Royal Veterinary College (RVC) are trying to establish an optimum horse riding style to train junior jockeys, as well as enhance safety, health and well-being of both racehorses and jockeys. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Bear Cubs Tumble for the Media

Bear Cubs Tumble for the Media

Reuters - Light News Video Online (Mar. 26, 2015) — Two Andean bear cubs are unveiled at the U.S. National Zoo in Washington, D.C. Alicia Powell reports. Video provided by Reuters
Powered by NewsLook.com
Botswana Talks to End Illegal Wildlife Trade

Botswana Talks to End Illegal Wildlife Trade

AFP (Mar. 25, 2015) — Experts are gathering in Botswana to try to end the illegal wildlife trade that is decimating populations of elephants, rhinos and other threatened species. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins