Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Multiple genes permit closely related fish species to mix and match their color vision

11.10.2005


Vision, like other biological attributes, is shaped by evolution through environmental pressures and demands, and even closely-related species that are in other ways very similar might respond to their particular environments by interpreting the visual world slightly differently, using photoreceptors that are attuned to particular wavelengths of light. By studying a special group of closely-related fish species inhabiting the Great Lakes of Africa, researchers have uncovered clues to understanding how the components of color vision can undergo change over a relatively short period of evolutionary time.


Credit: Justin Marshall



The work is reported by James K. Bowmaker of University College London, Karen L. Carleton of the University of New Hampshire, and their colleagues.

Cichlid fish of the East African Rift Lakes are renowned for their diversity: Owing to migrations of ancestor species out of Lake Tanganyika and into other lakes, such as Lake Malawi, it has been estimated that hundreds of new cichlid species have arisen in these lakes in the last 100,000 years. Thanks to the relatively recent colonization by these fish of different ecological niches, as well as the prominent role of nuptual coloring in the mating preferences of these species, the cichlids offer a unique opportunity to study how color vision can undergo change in rapidly evolving species. For example, because color plays a significant role in mate choice, differences in color vision could greatly influence and even drive cichlid speciation.


In the new work, the researchers performed physiological and molecular genetic analyses of color vision in cichlid fish from Lake Malawi and demonstrated that differences in color vision between closely related species arise from individual species’ using different subsets of distinct visual pigments. The scientists showed that although an unexpectedly large group of these visual pigments are available to all the species, each expresses the pigments selectively, and in an individual way, resulting in differences in how the visual world is sensed.

The researchers identified a total of seven "cone" (color-sensing) visual pigments underlying color vision in these cichlids. They have measured the sensitivities of the cones to different wavelengths of light and isolated the seven genes that give rise to the pigment proteins. The seven cone types have maximum sensitivities ranging from the red end of the spectrum right through to the ultraviolet--light outside the range of human sensitivity. The researchers showed that in order to tune its color vision, each cichlid species primarily expresses three of the seven cone pigment genes encoded by their genomes.

It is not clear why such closely related cichlid species have evolved such different visual sensitivities, but the sensitivities most likely relate to such selective forces as foraging specializations and subtle differences in the underwater light environment. Evolutionary comparison of pigment genes suggests that other groups of fish may use a similar strategy for shaping their color vision.

Heidi Hardman | EurekAlert!
Further information:
http://www.current-biology.com

More articles from Life Sciences:

nachricht A novel synthetic antibody enables conditional “protein knockdown” in vertebrates
20.08.2018 | Technische Universität Dresden

nachricht Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>