Navigation Links
Advantages of living in the dark: The multiple evolution events of 'blind' cavefish
Date:1/22/2012

The blind Mexican cavefish (Astyanax mexicanus) have not only lost their sight but have adapted to perpetual darkness by also losing their pigment (albinism) and having altered sleep patterns. New research published in BioMed Central's open access journal BMC Evolutionary Biology shows that the cavefish are an example of convergent evolution, with several populations repeatedly, and independently, losing their sight and pigmentation.

The blind cavefish and the surface dwelling Mexican tetra, despite appearances, are the same species and can interbreed. The cavefish are simply a variant of the Mexican tetra, albeit one adapted to living in complete darkness. A team of researchers from Portugal, America, and Mexico studied the DNA from 11 populations of cavefish (from three geographic regions) and 10 populations of their surface dwelling cousins to help understand the evolutionary origin of the physical differences between them.

While results from the genotyping showed that the surface populations were genetically very similar, the story for the cave populations was very different. The cave forms had a much lower genetic diversity, probably as a result of limited space and food. Not surprisingly the cave populations with the most influx from the surface had the highest diversity. In fact there seemed to be a great deal of migration in both directions.

It has been thought that historically at least two groups of fish lived in the rivers of Sierra de El Abra, Mexico. One group originally colonized the caves, but became extinct on the surface. A different population then restocked the rivers and also invaded the caves.

Prof Richard Borowsky, from the Cave Biology Group at New York University explained, "We were fortunate in being able to use A. mexicanus as a kind of 'natural' experiment where nature has already provided the crosses and isolation events between populations for us. Our genotyping results have provided evidence that the cave variant had at least five separate evolutionary origins from these two ancestral stocks."

Dr Martina Bradic who lead the research continued, "Despite interbreeding and gene flow from the surface populations the eyeless 'cave phenotype' has been maintained in the caves. This indicates that there must be strong selection pressure against eyes in the cave environment. Whatever the advantage of the eyeless condition, it may explain why different populations of A. mexicanus cave fish have independently evolved the same eyeless condition, a striking example of convergent evolution."

Media Contact
Dr Hilary Glover
Scientific Press Officer, BioMed Central
Tel: 44-20-3192-2370
Mob: 44-778-698-1967
Email: hilary.glover@biomedcentral.com

Notes to Editors

1. Gene flow and population structure in the Mexican blind cavefish complex (Astyanax mexicanus) Martina Bradic, Peter Beerli, Francisco Garca-de Len, Sarai Esquivel-Bobadilla and Richard Borowsky BMC Evolutionary Biology (in press)

Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.

Article citation and URL available on request at press@biomedcentral.com on the day of publication.

2. BMC Evolutionary Biology is an open access, peer-reviewed journal that considers articles on all aspects of molecular and non-molecular evolution of all organisms, as well as phylogenetics and palaeontology.

3. BioMed Central (http://www.biomedcentral.com/) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector.


'/>"/>
Contact: Dr Hilary Glover
hilary.glover@biomedcentral.com
44-020-319-22370
BioMed Central
Source:Eurekalert  

Related biology news :

1. New DNA and RNA aptamers offer unique therapeutic advantages
2. New research: Post-exercise recovery advantages of lowfat chocolate milk
3. Assessing agroforestrys advantages
4. Being small has its advantages, if you are a leaf
5. NSF funds new Center for the Physics of Living Cells at Illinois
6. TB bacterium uses its sugar coat to sweeten its chances of living in lungs
7. Living fossil tree contains genetic imprints of rain forests under climate change
8. New method provides panoramic view of protein-RNA interactions in living cells
9. Novel technique for fluorescence tomography of tumors in living animals
10. MIT nanotubes sniff out cancer agents in living cells
11. Reproductive life of male mice is increased by living with females
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Advantages of living in the dark: The multiple evolution events of 'blind' cavefish
(Date:6/23/2017)... and ITHACA, N.Y. , June 23, ... University, a leader in dairy research, today announced a ... to help reduce the chances that the global milk ... of this dairy project, Cornell University has become the ... the Food Supply Chain, a food safety initiative that ...
(Date:5/6/2017)... -- RAM Group , Singaporean based technology ... biometric authentication based on a novel  quantum-state ... perform biometric authentication. These new sensors are based on a ... Group and its partners. This sensor will have widespread ... security. Ram Group is a next generation sensor ...
(Date:4/13/2017)... , April 13, 2017 UBM,s Advanced Design ... will feature emerging and evolving technology through its ... Summits will run alongside the expo portion of the ... panels and demonstrations focused on trending topics within 3D ... design and manufacturing event will take place June 13-15, 2017 ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... The ... three Winners and six Finalists of the 2017 Blavatnik Regional Awards for Young ... Family Foundation and administered by the New York Academy of Sciences to honor ...
(Date:10/12/2017)... ... October 12, 2017 , ... BioMedGPS announces expanded ... of its newest module, US Hemostats & Sealants. , SmartTRAK’s US Market for ... fibrin sealants, synthetic sealants and biologic sealants used in surgical applications. BioMedGPS estimates ...
(Date:10/11/2017)... Charlotte, N.C. (PRWEB) , ... October 11, 2017 ... ... ARCS® Foundation President Andi Purple announced Dr. Suneel I. Sheikh, the ... Laboratories ( ASTER Labs ), Inc. has been selected for membership in ...
(Date:10/11/2017)... ... October 11, 2017 , ... ComplianceOnline’s Medical Device Summit is back ... 8th June 2018 in San Francisco, CA. The Summit brings together current and former ... CEOs, board directors and government officials from around the world to address key issues ...
Breaking Biology Technology: