How many genes influence a complex trait, like weight, height or body type?
And why does the answer matter?
Among other reasons, because the "Green Revolution" that multiplied crop yields has to be followed by a "Blue Revolution" in ocean farming, according to marine biologists at the University of Southern California.
"We’re going to have to make future decisions as a society how to provide enough food for a growing population," said Donal Manahan, co-author of a study on oyster growth appearing online this week in Proceedings of the National Academy of Sciences Early Edition.
Currently a delicacy, oysters fed the masses in the past and could again become "the soy bean of the sea" as traditional fisheries collapse, Manahan predicted.
He and senior author Dennis Hedgecock linked growth rate in oysters to approximately 350 genes, or 1.5 percent of the more than 20,000 genes in the oyster genome.
To the authors’ knowledge, this is the first estimate of the number of genes that determine growth rate in any animal.
Specifically, the authors discovered the genes responsible for "hybrid vigor," or the ability of some children of crossbreeding to outgrow both parents. Hybrid vigor is of evolutionary as well as agricultural interest because it appears to favor biodiversity.
Many plants have hybrid vigor. Seed companies exploited this property to increase corn yields seven-fold from the 1920s to the present.
Most animals do not express hybrid vigor to such an extent, the authors said. That makes oysters particularly strong candidates for aquaculture.
"Their hybrids grow much faster than either of the parents. And this is exactly like corn," Manahan said.
The PNAS study may lead to improved breeding both on land and sea. The green revolution worked by trial and error, with companies trying every possible cross of corn strains to find the best hybrids.
"A century after its discovery in corn, we still don’t know why plants have hybrid vigor, despite the economic and evolutionary importance of this phenomenon," Hedgecock explained.
Knowing the genes for hybrid vigor may enable companies to develop the best cross of corn strains, or oyster types, without guesswork.
The lines would not be genetically modified, only screened and matched as in a dating service.
The goal is efficient and sustainable domestication of oysters and other promising ocean species, mostly shellfish. Oysters already are the number one farmed aquatic species worldwide.
Aquaculture of large fish remains environmentally challenging, Manahan and Hedgecock noted.
Another problem is the apparent lack of hybrid vigor in most fish. Even in oysters, the researchers found the rules of hybrid vigor to be more complicated than predicted by classical ideas in genetics and physiology.
For example, some genes were expressed much less in the offspring than in either parent, a pattern the authors call "underdominance." Very few genes were expressed as the average of the expression in their parents.
Hedgecock called the underdominance patterns "one of the more surprising findings" of the study.
Carl Marziali | EurekAlert!
Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)
North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Life Sciences
23.03.2018 | Materials Sciences
23.03.2018 | Process Engineering