The symbiosis between special algal species and reef corals is the foundation of a highly productive and biologically complex ecosystem, but our understanding of how this symbiosis is established by new corals has been limited by the fact that the symbiotic algae are difficult to find and study in the ocean.
But now a group of researchers has successfully identified algae of the genus known to represent coral symbionts, and has gone on to show that the isolated algae are indeed capable of establishing symbioses with new corals. The findings, which potentially bolster future efforts to protect and rehabilitate coral reefs, are reported by a group including Mary Alice Coffroth of the University at Buffalo and appear in the December 5th issue of Current Biology.
In response to environmental stresses, coral reefs around the world are in a decline due in large part to coral bleaching—loss of the symbiotic photosynthetic algae that live within corals and provide much of their energy. These symbiotic algae are essential to their host’s survival, but many corals must acquire their symbionts anew with the emergence of each generation. However, it has remained unclear how newly settled coral polyps acquire their symbionts in the ocean.
Organisms that resemble coral symbionts—dinoflagellates that are similar to those of the Symbiodinium genus that grow within corals—have been isolated from both sand and the water column; however, neither the locations of these populations nor their ability to establish symbioses is known. For both our understanding of reef ecosystems and their conservation, it is critical to recognize where these symbionts reside in the ocean environment.
In the new work, the researchers succeeded in identifying Symbiodinium in the water column as well as on ocean-bottom substrates. Most importantly, the researchers also demonstrated that a subset of Symbiodinium found in the water and on benthic substrates (that is, on algae and sediments) can infect new coral polyps. These isolates are therefore capable of establishing symbioses with corals and thus point to environmental sources of symbionts that may prove important in the recovery of reef-building corals after bleaching events.
Heidi Hardman | EurekAlert!
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Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.
Graphene is up to the job
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
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...
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