Diatoms (unicellular photosynthetic organisms) reproduce through asexual cell division alternating with short periods of sexual reproduction.
A German and Belgian team has now determined that pheromones play an important role in this. As the researchers report in the journal Angewandte Chemie, they were able to isolate and structurally characterize one of these lures.
Diatoms have hard mineral shells that are formed like a hatbox from two overlapping halves. During the asexual reproduction phase, the new cells each get one half of the original shell and make the second half themselves. Because the new part of the shell is made inside the shell of the mother cell, the cell size of a given population constantly decreases. Once a critical cell size is reached, the diatoms must switch to sexual reproduction in order to survive. This produces a cell of the original size.
When S. robusta reaches its species-specific critical cell size, two types of sexual cell are differentiated; these are designated as + and – .
Afterwards, all of the cells of the mobile + mating type gather around an attracting – cell. A team led by Georg Pohnert, Marnik Vuylsteke, and Wim Vyverman has now been able to prove that both mating types produce chemical signals that activate the mating behavior of their partner. To do this, the researchers extracted the culture medium from diatoms in various states and used this extracted material as a source of pheromones.
They demonstrated that chemical messengers must be activated in order to herald the sexual readiness of the two types of cells. The – cells thus release substances that greatly increase the mobility of the + cells; and the + cells release substances that induce the – cells to become prepared to mate and cause them to excrete the actual attracting pheromone. Both mating types rely on signaling molecules to ensure the presence of a mature mating partner before they invest in a sexual response themselves. This increases the chances of successful sexual reproduction.By comparing the different metabolic products released during the different phases of the reproductive cycle using a method known as “metabolomics”, the researchers found the lure used by the – cells. They isolated it and identified it as diproline. They were able to synthesize this substance by starting from the amino acid proline and determined its absolute configuration.
Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology
The secret sulfate code that lets the bad Tau in
16.07.2018 | American Society for Biochemistry and Molecular Biology
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
16.07.2018 | Physics and Astronomy
16.07.2018 | Life Sciences
16.07.2018 | Earth Sciences