“Don't be a frog!“ people say in jest when someone hesitates instead of acting straight away. However to be called a frog should actually be a reason to strengthen one's self-confidence. After all frogs are real winners – at least from the point of view of evolutionary biology: Nearly 6.000 species are known today.
Specimen of the South African clawed frog (Xenopus laevis), that zoologists at Jena University are doing research on. Photo: Jan-Peter Kasper/University Jena
“In terms of numbers frogs are superior to all the other amphibians, and even mammals“, says Professor Dr. Lennart Olsson from the Friedrich Schiller University Jena (Germany). Professor Olsson's research group for Systematic Zoology examines these animals’s special secret of success. “We are interested in how the frogs developed in such a great variety and which evolutionary new development is responsible for making frogs so particularly successful“, Jennifer Schmidt from Olsson's team explains.
Their evolutionary success is literally written all over the frogs' faces: Certain forms of cartilage and bone structures in the region of the head of the tadpoles are among the frogs' “innovations“. These structures only to be found in frogs appear in the oral region. They enable the tadpoles – of the South African claw frog (Xenopus laevis) – particularly well to chip vegetarian food from the soil and from stones or to filter it from the water.
In their latest study which has been published in the science magazine “Journal of Anatomy“ together with colleagues from Ulm Jennifer Schmidt analysed the central factor for the development of these morphologically distinctive features of the tadpoles. It is well known from earlier analyses, that the gene “FOXN3“ plays a key role in the embryonal development of the heads of claw frogs. “It is responsible for the normal development of cartilages, bones and muscles“, Jennifer Schmidt explains.
In the newly published study the 25 year old doctoral candidate and scholar of the Konrad-Adenauer-Stiftung analysed larvae of the claw frog after the “FOXN3“-gene had been cut off. Then she compared them with untreated larvae. “Our analyses with microCT show that the larvae without an intact ‘FOXN3’-gene are developing normally up to a certain time.“ But then the development slows down, says Jennifer Schmidt. “On the whole these animals grow more slowly.“ Most of all the cartilages, the bones and muscles don't develop properly. Deformations and loss of functions occur. However not all cartilages and muscles are affected by the cut-off gene. “We were able to show that the ‘FOXN3’ most of all influences the development of the cartilages in the oral region and the gills“, Professor Olsson points out. These structures in particular belong to the evolutionary new developments typical of frogs, which are missing in other amphibians. Jennifer Schmidt would like to continue her analyses in her thesis. “We are going to compare the embryonal development of the claw frogs with those of other amphibians“, the zoologist says. It would be interesting to find out to what extent the genetic control of those new developments changed in the course of the evolution.Original Publication:
Ute Schönfelder | Uni Jena
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy