A team led by Helena Bailes at the School of Biomedical Sciences, University of Queensland, Brisbane, Australia, analysed retinas from Australian lungfish (Neoceratodus forsteri), thought to be the closest living relative to the first terrestrial vertebrates. The researchers then compared these to other fish and amphibian retinas. The DNA of five visual pigment (opsin) genes in the retinas of lungfish reveals that these have more in common with four-legged vertebrates (tetrapods) than with fish retinas.
Although lungfish mainly take in oxygen through their gills like most fish, they can also breathe air if water quality is poor. Lungfish were previously thought to have poor eyesight due to their small eyes, low spatial resolving power, sluggish behaviour in captivity and ability to detect prey using electroreception. N.forsteri inhabits a brightly lit, shallow freshwater habitat similar to the environment from which terrestrial evolution probably occurred. This prompted the team to investigate the complement of opsins expressed in N. forsteri, to trace photoreception's evolution in ancestral tetrapods.
The study paves the way for behavioural work with lungfish to see if they can discriminate between objects based on colour.
"The genus Neoceratodus, of which N. forsteri is the sole survivor, is found in the fossil record from the Lower Cretaceous period 135 million years ago and therefore N. forsteri lays claim to being the oldest surviving vertebrate genus," says Bailes. "The visual system of N. forsteri may represent an evolutionary design most closely reflecting that present just prior to the emergence of land vertebrates in the Devonian period."
Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory
‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität Dresden
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
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The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
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