The evolution of new traits with novel functions has always posed a challenge to evolutionary biology. Studying the color markings of cichlid fish, Swiss scientists were now able to show what triggered these evolutionary innovations, namely: a mobile genetic element in the regulatory region of a color gene. Their results have been published in the latest issue of the renowned scientific journal Nature Communications.
Biological evolution is in general based on the progressive adaption of traits through natural or sexual selection. However, ever so often, complex traits with completely new functions arise such as insect wings, feathers or the placenta.
The anal fin of the haplochromine cichlid Astatotilapia burtoni bearing the characteristic egg-spots
Fig: Zoology, University of Basel
A female haplochromine cichlid while mouth-breeding
Fig: Anya Theis, Zoology, University of Basel
The evolution of such evolutionary innovations is often hard to explain relying solely on the model of progressive modification of already existing traits. Furthermore, it is largely unknown which genome modifications actually lead to evolutionary innovations.
A team of Basel researchers jointly lead by Prof. Walter Salzburger from the Department of Zoology and Prof. Markus Affolter from the Biozentrum at the University of Basel now clarified the genetic and developmental origins of an evolutionary innovation in African cichlids.
The males of over 1,500 species feature conspicuous color markings on their anal fins – so called egg-spots – that play a central role in the mating behavior of these mouth-breeding fish. Immediately upon spawning, the female gathers up her eggs into the mouth before fertilization.
The male then presents his egg-spots to which the female responds by snatching and bringing her mouth close to the male's genital opening – only now are the eggs being fertilized inside the female's mouth.
The Basel biologists were able to show that the evolution of egg-spots is linked to the insertion of a mobile genetic element – a “jumping gene” – in the regulatory region of a newly identified pigmentation gene. These mobile elements are short DNA strings that are able to change their position within the genome and can influence the regulation of other genes
In the case of the cichlid's egg-spots, the presence of the “jumping gene” upstream of a pigmentation gene with the name fhl2b leads to an alteration in gene expression in pigmentation cells and therefore to the development of the characteristic egg-spot pattern on the male cichlids’ anal fin.
The scientists came to this conclusion after having induced the cichlids’ genome segment containing the mobile element into zebrafish embryos. In fact, they were able to locate the according expression in a specific group of pigmentation cells. “These results illustrate once more the importance of changes in gene expression in evolution”, comments Prof. Walter Salzburger the findings.
M. Emilia Santos, Ingo Braasch, Nicolas Boileau, Britta S. Meyer, Loic Sauteur, Astrid Böhne, Heinz-Georg Belting, Markus Affolter & Walter Salzburger
The evolution of cichlid fish egg-spots is linked with a cis-regulatory change
Nature Communications 5:5149 (10.1038/ncomms6149)
David Brawand et al.
The genomic substrate for adaptive radiation in African cichlid fish
Nature 513: 375-381.
Prof. Walter Salzburger, Department of Environmental Science, University of Basel, Zoology, phone: +41 (0)61 267 03 03, email: firstname.lastname@example.org
Olivia Poisson | Universität Basel
Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex
New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center
Russian researchers together with their French colleagues discovered that a genuine feature of superconductors -- quantum Abrikosov vortices of supercurrent -- can also exist in an ordinary nonsuperconducting metal put into contact with a superconductor. The observation of these vortices provides direct evidence of induced quantum coherence. The pioneering experimental observation was supported by a first-ever numerical model that describes the induced vortices in finer detail.
These fundamental results, published in the journal Nature Communications, enable a better understanding and description of the processes occurring at the...
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
25.06.2018 | Physics and Astronomy
25.06.2018 | Earth Sciences
25.06.2018 | Power and Electrical Engineering