Featured Research

from universities, journals, and other organizations

Water flea: First crustacean genome is sequenced

Date:
February 3, 2011
Source:
Marine Biological Laboratory
Summary:
The ubiquitous freshwater "water flea," Daphnia pulex, is a valuable "sentinel species" for the presence of toxins and pollutants in the environment.

The freshwater zooplankton Daphnia pulex (water flea), a near-microscopic crustacean that lives in ponds and lakes, has a translucent body and a compound eye.
Credit: Jan Michels, Christian-Albrechts-Universitaet zu Kiel

The ubiquitous freshwater "water flea," Daphnia pulex, may be too small to see, but it has amply proven its value as an "sentinel species" for the presence of toxins and pollutants in the environment.

Daphnia's response to exposure to toxic metals and other chemical pollutants is well studied, and this information is routinely used by groups such as the US Environmental Protection Agency (EPA) to define regulatory limits, and to monitor industrial and municipal discharges.

This week, Daphnia pulex is receiving an enormous pat on the back from the scientific community: It is the first crustacean to have its complete genome sequenced. The sequence is being published February 4 in the journal Science by members of the Daphnia Genomics Consortium, an international network of scientists led by the Center for Genomics and Bioinformatics at Indiana University-Bloomington and the Department of Energy's Joint Genome Institute.

Joshua Hamilton, senior scientist and chief academic and scientific officer at the Marine Biological Laboratory (MBL) in Woods Hole, Mass., is co-author of an important companion paper to the Daphnia genome sequence. That paper, published in 2007, was the first study of the genetic basis for Daphnia's adaptive response to sub-lethal levels of a major environmental contaminant, the metal cadmium. Cadmium, which is highly toxic to aquatic life (and to humans), is one of the most common contaminants found in the U.S. EPA Superfund sites.

The technologies described in the 2007 paper (cDNA microarrays) were the first genomic tools developed for Daphnia and they are applicable to testing Daphnia's genetic response to a wide range of environmental contaminants. Subsequently, many other environmental stressors have been tested using Daphnia.

"Daphnia can serve as an important 'canary in a coal mine' for freshwater ecosystems and their response to environmental contamination," says Hamilton. "When the Daphnia population is impacted, it is likely that the entire ecosystem is being adversely affected and may be on the verge of collapse."

Hamilton, then at Dartmouth Medical School, and colleagues at Dartmouth and Indiana University demonstrated that Daphnia can adapt to increasing levels of cadmium by up-regulating a unique version of a key protective molecule called metallothionein, but at a very high cost. Although the individuals could resist the high levels of cadmium and survive, their reproductive success plummeted to a fraction of that of animals in uncontaminated waters, which after only a few generations threatened the entire population's long-term survival.

Daphnia is emerging as a model organism for a new field of science -- environmental genomics -- that aims to better understand how the environment and genes interact. Scientific developments from this field can be used to manage our water resources and protect human health from chemical pollutants in the environment, and serve as a way to understand how our own bodies respond to these environmental challenges.

"Until now, Daphnia has primarily been used as sentinel species for monitoring the integrity of aquatic ecosystems," says Joseph Shaw, co-author of the cadmium study (as a former postdoctoral fellow with Hamilton), co-author of the new Science paper, and now a biologist at Indiana University-Bloomington's School of Public and Environmental Affairs. "But with many shared genes between Daphnia and humans, we will now also apply Daphnia as a surrogate model to address issues directly related to human health. This puts us in a position to begin integrating studies of environmental quality with research of human diseases."


Story Source:

The above story is based on materials provided by Marine Biological Laboratory. Note: Materials may be edited for content and length.


Journal References:

  1. Colbourne, J.K. et al. The Ecoresponsive Genome of Daphnia pulex. Science, Feb. 4, 2011 DOI: 10.1126/science.1197761
  2. Joseph R Shaw, John K Colbourne, Jennifer C Davey, Stephen P Glaholt, Thomas H Hampton, Celia Y Chen, Carol L Folt, Joshua W Hamilton. Gene response profiles for Daphnia pulex exposed to the environmental stressor cadmium reveals novel crustacean metallothioneins. BMC Genomics, 2007; 8 (1): 477 DOI: 10.1186/1471-2164-8-477

Cite This Page:

Marine Biological Laboratory. "Water flea: First crustacean genome is sequenced." ScienceDaily. ScienceDaily, 3 February 2011. <www.sciencedaily.com/releases/2011/02/110203141824.htm>.
Marine Biological Laboratory. (2011, February 3). Water flea: First crustacean genome is sequenced. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2011/02/110203141824.htm
Marine Biological Laboratory. "Water flea: First crustacean genome is sequenced." ScienceDaily. www.sciencedaily.com/releases/2011/02/110203141824.htm (accessed September 20, 2014).

Share This



More Earth & Climate News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Rally Held in India Ahead of UN Summit

Climate Change Rally Held in India Ahead of UN Summit

AFP (Sep. 20, 2014) Some 125 world leaders are expected to commit to action on climate change at a UN summit Tuesday called to inject momentum in struggling efforts to tackle global warming. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com
Raw: Wildfires in CA Burn Forest Asunder

Raw: Wildfires in CA Burn Forest Asunder

AP (Sep. 18, 2014) An out-of-control Northern California wildfire has nearly 2,800 people from their homes as it continues to grow, authorities said Thursday. Authorities said a man has been arrested on suspicion of arson for starting the fire on Saturday. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
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:
from the past week

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