Navigation Links
Adaptation to parasites drive African fishes along different evolutionary paths

Quebec City, Canada - An international team of scientists from Canada (Universit Laval), the U.K. (University of Hull, Cardiff University) and Spain (Do ana Biological Station), have discovered that a pair of closely related species of East African cichlid fishes a group of fish whose diversity comprising hundreds of species has puzzled evolutionary biologists for decades evolved divergent immune gene adaptations which might explain why they do not interbreed, despite living side by side.

The two species ( Pseudotropheus emmiltos and Pseudotropheus fainzilberi ) are found in the north western part of Lake Malawi. Until now, the only known difference between them was the color of their dorsal fin. Many researchers believe that African cichlids recognize conspecifics from these kinds of colour differences, which are thought to result from sexual selection. However, recent mate choice experiments have shown that female P. emmiltos recognize males of their own species from P. fainzilberi males based on olfactory communication rather than color.

Some of the genes known to influence mating behavior through olfaction in other vertebrate species are genes of the major histocompatibility complex (MHC). These genes code for receptor that bound molecules produced by infectious agents and present them to specialized cells of the immune system which then launch an immune attack on the microbes. They are the most diverse genes found in vertebrate genomes and individuals of some species, including humans, are able to "smell" other individuals variability at these genes and adjust their mate choice in order to optimize the effectiveness of their offspring's immune system. Analysis of MHC genes between P. emmiltos and P. fainzilberi revealed that the two species were genetically more different at these sites involved in contacting and presenting molecules to immune cells than at other sites of the gene's DNA sequence that do not play functional roles.

These results show that natural selection has driven the evolution of these genes in different direction between the two species. Furthermore, the researchers showed that infecting parasites found on the two species were significantly different, as predicted based on the known immune function of MHC genes. "The mechanisms having produced the hundreds of species of East African cichlid fishes in a relatively short period of time are unclear", says Jonatan Blais, the senior author of the paper." This is one of the first genetic adaptive differences between closely related East African cichlid species identified. As such, it improves our understanding of the recent evolution of this incredibly diverse group of fish by pointing to a trait that not only diverged for adaptive reasons but may also be involved in mating behavior."

"The precise role that this divergence played in the evolution of reproductive isolation has yet to be studied", comments Louis Bernatchez, co-author of the study." But it offers an exciting new perspective in the study of African cichlids speciation ".


Contact: Jonatan Blais
Public Library of Science

Related biology news :

1. 15 generations of untrained jocks, couch potatoes show big physiological adaptations
2. Otter adaptations: How do otters remain sleek and warm
3. Protein offers way to stop microscopic parasites in their tracks
4. Measuring hidden parasites in falciparum malaria
5. Researchers at UGA provide first look at protein expression in Chagas disease-causing parasites
6. Malaria parasites develop in lymph nodes
7. How healthy is that marsh? Biologists count parasites
8. Bacterial protein shows promise in treating intestinal parasites
9. Hopkins scientists link immune response to ghost parasites and severely congested sinuses
10. Parasites impact goes beyond host to affect ecosystem
11. Scientists identify molecular events that drive cell senescence
Post Your Comments:
(Date:10/29/2015)... OXFORD, Connecticut , October 29, 2015 /PRNewswire/ ... "Company"), a biometric authentication company focused on the ... Wocket® smart wallet announces that StackCommerce, a leading ... will be featuring the Wocket® smart wallet on ... NXTD ) ("NXT-ID" or the "Company"), a ...
(Date:10/27/2015)... 2015 In the present market scenario, security ... various industry verticals such as banking, healthcare, defense, electronic ... demand for secure & simplified access control and growing ... hacking of bank accounts, misuse of users, , and ... PC,s, laptops, and smartphones are expected to provide potential ...
(Date:10/27/2015)... SAN JOSE, Calif. , Oct. 27, 2015 /PRNewswire/ ... human interface solutions, today announced that Google has adopted ... family of touch controller solutions to power its newest ... Nexus 6P by Huawei. --> ... ecosystem partners like Google to provide strategic collaboration in ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... , November 25, 2015 ... cat and human plaque and pave the way for more ... problems in cats     --> ... most commonly diagnosed health problems in cats, yet relatively little ... now. Two collaborative studies have been conducted by researchers from ...
(Date:11/25/2015)... , Nov. 25, 2015  Neurocrine Biosciences, Inc. ... Gorman , President and CEO of Neurocrine Biosciences, will ... Conference in New York . ... visit the website approximately 5 minutes prior to the ... replay of the presentation will be available on the ...
(Date:11/25/2015)... ... November 25, 2015 , ... ... of Black Aerospace Professionals (OPBAP) has been formalized with the signing of a ... leaders met with OPBAP leaders Capt. Karl Minter and Capt. Albert Glenn Tuesday, ...
(Date:11/25/2015)... PORTLAND, Oregon , November 25, 2015 /PRNewswire/ ... Deep Market Research Report is a professional and ... Genomics industry.      (Logo: ... basic overview of the industry including definitions, classifications, ... analysis is provided for the international markets including ...
Breaking Biology Technology: