Featured Research

from universities, journals, and other organizations

Researchers Find Way To Reverse Evolution Of Cave Fish Blindness

Date:
August 3, 2000
Source:
University Of Maryland, College Park
Summary:
The old cliche "the blind leads the blind" may no longer apply to a population of cave fish. Eye parts lost during the past million years of evolution were restored in just a matter of days after a lens transplant from a sighted surface-dwelling fish of the same species (Astyanax mexicanus), according to a University of Maryland biology research report featured in the July 28 issue of Science.

COLLEGE PARK, Md. - The old cliche "the blind leads the blind" may no longer apply to a population of cave fish. Eye parts lost during the past million years of evolution were restored in just a matter of days after a lens transplant from a sighted surface-dwelling fish of the same species (Astyanax mexicanus), according to a University of Maryland biology research report featured in the July 28 issue of Science.

This eye-opening result sheds light on understanding the role of genetic factors in eye growth and development according to William Jeffery, Maryland professor and biology chair, who coauthored the Science paper with Yoshiyuki Yamamoto, a postdoctoral researcher in Maryland's biology department.

Within eight days of implanting a lens from a sighted surface-dwelling fish to a blind cave fish of the same species, Maryland researchers began to see an eye develop from underneath a flap of skin. After two months, the cave fish had grown a large restored eye with a distinct pupil, cornea and iris. In addition, the retina of the restored eye showed rod photoreceptor cells, which are rare in the degenerate cave fish eye.

"This offers clues about what sort of molecules are involved in eye growth of any vertebrate and it shows the growth of an eye is controlled in a large part by the lens," said Jeffery.

Although Jeffery and Yamamoto can't say whether cave fish regain sight after having a restored eye, this research suggests a simple method in testing factors that control eye-growth.

"Our current research focuses on identifying basic development mechanisms in embryos that can be studied in the laboratory. Though we are not working with human patients, these findings could someday prove useful to our colleagues in clinical practice," said Jeffery.

Thousands of fish gathered in Mexican caves

During this research, Jeffery and his students collected thousands of cave fish from seven different caves in northeastern Mexico. These ghostly, pale fish live only in dark caves, depend on an acute sense of smell to find food and are not a target for predators, which are rarely present in caves.

"Our system deals with fish of the exact same species, but their living space and behavior greatly differ. What makes this kind of research especially interesting is determining what makes them different," said Yamamoto.

The Science paper notes cave fish begin to form eyes as embryos, but the young lens deteriorates and the cornea, iris, pupil and other optic tissues remain undeveloped. In adult cave fish, the degenerate eye sinks into the orbit and is covered by a flap of skin.

When the scientists reversed the experiment, where surface-dwelling fish received the regenerated lens from a cave fish, the transplant failed to trigger any significant eye growth.

According to the researchers, these results show cave fish have lost the ability to promote eye development. With these findings, the scientists conclude, "evolutionary changes in an inductive signal from the lens are involved in cave fish eye degeneration."

However, Jeffery and Yamamoto caution the possibility of other factors contributing to eye loss is currently under investigation in their laboratory. The researchers are hopeful if they can stop cave fish lens from triggering eye regression, they can learn exactly how the mechanism works. Research described in the Science paper was supported by the National Science Foundation.


Story Source:

The above story is based on materials provided by University Of Maryland, College Park. Note: Materials may be edited for content and length.


Cite This Page:

University Of Maryland, College Park. "Researchers Find Way To Reverse Evolution Of Cave Fish Blindness." ScienceDaily. ScienceDaily, 3 August 2000. <www.sciencedaily.com/releases/2000/07/000728082041.htm>.
University Of Maryland, College Park. (2000, August 3). Researchers Find Way To Reverse Evolution Of Cave Fish Blindness. ScienceDaily. Retrieved August 27, 2014 from www.sciencedaily.com/releases/2000/07/000728082041.htm
University Of Maryland, College Park. "Researchers Find Way To Reverse Evolution Of Cave Fish Blindness." ScienceDaily. www.sciencedaily.com/releases/2000/07/000728082041.htm (accessed August 27, 2014).

Share This




More Health & Medicine News

Wednesday, August 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Predicting Heart Transplant Rejection With a Blood Test

Predicting Heart Transplant Rejection With a Blood Test

Ivanhoe (Aug. 27, 2014) Now a new approach to rejection of donor organs could change the way doctors predict transplant rejection…without expensive, invasive procedures. Video provided by Ivanhoe
Powered by NewsLook.com
Better Braces That Vibrate

Better Braces That Vibrate

Ivanhoe (Aug. 27, 2014) The length of time you have to keep your braces on could be cut in half thanks to a new device that speeds up the process. Video provided by Ivanhoe
Powered by NewsLook.com
Smartphone App Tracks Your Heart Rate

Smartphone App Tracks Your Heart Rate

Ivanhoe (Aug. 27, 2014) A new app that can track your heart rate 24/7 is available for download in your app store and its convenience could save your life. Video provided by Ivanhoe
Powered by NewsLook.com
Stroke in Young Adults

Stroke in Young Adults

Ivanhoe (Aug. 27, 2014) A stroke can happen at any time and affect anyone regardless of age. This mother chose to give her son independence and continue to live a normal life after he had a stroke at 18 years old. Video provided by Ivanhoe
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