Featured Research

from universities, journals, and other organizations

Atlantic Salmon Cancer Virus Identified

Date:
January 5, 1999
Source:
Cornell University
Summary:
Researchers in the Cornell University College of Veterinary Medicine, working with federal fisheries personnel, have made the first identification of a virus believed responsible for cancerous tumors in Atlantic salmon in the New England region.

ITHACA, N.Y. -- Researchers in the Cornell University College of Veterinary Medicine, working with federal fisheries personnel, have made the first identification of a virus believed responsible for cancerous tumors in Atlantic salmon in the New England region.

Related Articles


The name given to the newly characterized virus is salmon swimbladder sarcoma virus (SSSV). It is not seen as a human health hazard.

Researchers used PCR (polymerase chain reaction) cloning and gene-sequencing techniques developed at Cornell to make the first positive identification of the virus, believed responsible for tumors that killed breeding-stock Atlantic salmon in the U.S. Fish and Wildlife Service hatchery in North Attleboro, Mass. The infected fish originally had been collected from the Pleasant River in Maine where they were part of a breeding program to restock Atlantic salmon in the river.

In the past the disease was found in commercial aquaculture where salmon were grown in off-shore pens. A cancer with similar symptoms was reported in some farm-raised Atlantic salmon in Scotland in 1978, before modern genetic testing methods were available. At the time, Scottish scientists reported seeing "virus-like particles" during microscopic examination of the salmon tumors. To date this disease has not been seen in any commercially raised Atlantic salmon in the United States.

The virus from the North Attleboro hatchery fish was identified at Cornell by James W. Casey, associate professor of veterinary microbiology and immunology and a specialist in molecular virology; Paul R. Bowser, professor of veterinary microbiology and immunology and a specialist in fish pathology; and Sandra L. Quackenbush, a molecular virologist working in Casey's laboratory, now an assistant professor at the University of Kansas. The Cornell scientists worked in cooperation with Larry Lofton and John Coll of the U.S. Fish and Wildlife Service.

"We don't yet know how this virus is actually transmitted from one fish to another," Casey says. "This could occur through so-called vertical transmission in reproductive products, the eggs and sperm of breeding salmon; or perhaps through horizontal transmission, with the virus entering the bodies through the skin or gills, in water they ingest or on food they eat. Our concern is that the virus is in the environment, and the levels of infection need to be determined."

SSSV is not a health hazard to humans, according to Bowser, the Cornell fish pathologist. "These viruses are generally species-specific, meaning that they only infect and cause disease in a single species. There is absolutely no evidence that this virus is a human pathogen. But infection is a real problem for the Atlantic salmon. Although tumors are fatal, it appears that viral infection alone reduces their vitality and reproductive success."

The virus causes a slow-growing cancer that can take two years to produce a noticeable tumor on swim-bladders, Bowser notes. By the time the swimbladder tumor is detectable, from a bulging in the side of the fish, the salmon are near death. An earlier sign of swimbladder sarcoma might be blood hemorrhaging from the fins.

The salmon tumors are similar to viral tumors seen on the skin of a freshwater fish, the walleye, Casey says. His laboratory has identified five different retroviruses that are associated with tumors in walleye and perch in lakes in upstate New York. The walleye tumors usually do not kill the fish, but rather seem to disappear spontaneously. Such regression of tumors is of interest to Casey, Bowser and other cancer researchers because an explanation for the phenomenon could lead to better treatment or prevention of human cancers.

SSSV is classified as a retrovirus, Casey says, because it contains hallmark sequence similarities to other members of this group. There are many well-studied retroviruses that cause cancers in chickens, mice, cats and humans, but SSSV is the first retrovirus of salmon that has been identified. "As natural habitats decline and investigators more intensively monitor aquatic animal health, additional tumors like these will be found," Casey says.

After their successful identification of the virus, the Cornell scientists hope to develop a rapid diagnostic test for SSSV. If routinely utilized at the salmon breeding facilities, such a test could help eliminate infected fish before the disease is transmitted to others, the Cornell scientists predict.

In the next step of the SSSV study, Bowser, Casey and Quackenbush plan to investigate virus transmission in a cooperative effort with Rocco Cipriano of the National Fish Health Laboratory of the U. S. Geological Survey. They also plan to examine various wild populations of Atlantic salmon in Maine with Michael Opitz of the Cooperative Extension Service of the University of Maine, and fish health specialists from the Lamar Fish Health Unit of the U. S. Fish and Wildlife Service.

"In the long term, this fish disease will be an excellent model to study the process of tumorogenesis and provide information relevant to the prevention of all cancers, whether human or animal," Casey says.


Story Source:

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


Cite This Page:

Cornell University. "Atlantic Salmon Cancer Virus Identified." ScienceDaily. ScienceDaily, 5 January 1999. <www.sciencedaily.com/releases/1999/01/990105075643.htm>.
Cornell University. (1999, January 5). Atlantic Salmon Cancer Virus Identified. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/1999/01/990105075643.htm
Cornell University. "Atlantic Salmon Cancer Virus Identified." ScienceDaily. www.sciencedaily.com/releases/1999/01/990105075643.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
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