(Press-News.org) NEWPORT, Ore. - Analyzing thousands of genetic markers in albacore tuna from the Pacific Ocean, researchers at Oregon State University have learned that just seven dozen of those markers are needed to determine which side of the equator a fish comes from.
The scientists also discovered that fish from different hemispheres intermingle and sometimes breed with each other.
Published Tuesday in Evolutionary Applications, the findings are an important step toward better understanding the population structure of a species that's a vital and inexpensive source of protein for people around the globe.
Albacore in the North and South Pacific Oceans are currently managed as separate stocks. The OSU study affirms this approach while also opening the door to more research into overlap and interbreeding that can be used to refine management strategies throughout the Pacific.
"Albacore support one of the world's largest and most valuable fisheries and one that is particularly important on the west coast of North America," said Kathleen O'Malley, an associate professor in the OSU College of Agricultural Sciences. "There's been a lot of work done to understand stock structure of the albacore globally, but research in the Pacific hasn't been very fine-tuned and has tended to generate as many questions as answers."
O'Malley, who is also the fisheries geneticist for the state of Oregon, noted that previous research involving tagged fish has revealed no movement of albacore from one side of the equator to the other. At the same time, previous genetic data have yielded no way to tell if a fish was from the North Pacific or South Pacific - hence the lack of understanding regarding the connectivity between the two populations.
O'Malley and postdoctoral research associate Felix Vaux, who led the study, looked at DNA from 308 fish from 12 locales around the Pacific. They identified nearly 13,000 genetic markers - DNA sequences with known physical locations on chromosomes - and learned that fewer than 100 of those markers told the tale of what part of the ocean a fish came from.
"We identified 12,872 markers and were able to discriminate between North and South Pacific albacore by using only 84 of them," Vaux said.
Those 84, he added, appear to be "under selection" and may reflect adaptive differences between the two albacore stocks. In any population, individuals with locally adapted traits tend to be the most successful reproductively, meaning that over time selection will increase the prevalence of those traits. With continuing, intense selection, adaptive traits become universal or close to it in a population or species.
"There is no complete genome for albacore to compare our data against, so we weren't able to determine which genes underlie these likely adaptive differences," O'Malley said. "In addition, we found that some fish have mixed genetic backgrounds - indicating that albacore from the North and South Pacific sometimes spawn at the same time and place and breed together. Also, we detected albacore with South Pacific genetic profiles in the North Pacific, providing evidence for migration across the equator that had earlier gone undetected via physical tagging data."
Future studies, she added, will use these genetic markers to more deeply investigate interbreeding between North and South Pacific albacore as well as migration between hemispheres.
O'Malley, who directs the State Fisheries Genomics Lab at OSU's Hatfield Marine Science Center, says that both genetic and demographic connectivity, while important for effective management and conservation strategies, are not well understood in most marine species.
Genetic diversity is an important tool for populations trying to adapt to climate change and other environmental perturbances, she said. With more variation, it is more likely that some individuals in a population will be suited to withstand the changes and produce offspring that are also able to thrive in the modified environment.
INFORMATION:
Collaborating with O'Malley and Vaux on this research were Sandra Bohn of the State Fisheries Genomics Lab and John Hyde of the National Marine Fisheries Service. Vaux is now a postdoctoral fellow at the University of Otago in Dunedin, New Zealand.
A Saltonstall-Kennedy Grant funded the study.
Overview:
A color illusion that strongly induces color contrast effect has been found by a research team at the Toyohashi University of Technology Department of Computer Science and Engineering, and Electronics-Inspired Interdisciplinary Research Institute (EIIRIS). The powerful visual illusion clarified a century-old contradiction relating to simultaneous color contrast theory. Through a human psychophysical experiment, the team demonstrated that the presence or absence of flanking contours formed from extremely thin white lines could be used to switch between contradictory visual phenomena (Figure 1), enabling consistent explanation for both discrepant ...
Tampa, FL (Feb. 10, 2021) - Percutaneous coronary intervention (PCI), commonly known as angioplasty with a stent, opens clogged arteries and saves lives. Despite its benefit in treating atherosclerosis that causes coronary artery disease, this common minimally-invasive procedure still poses severe complications for some patients.
Angioplasty involves inflating a balloon at the tip of a catheter to compress fatty deposits (plaques) against the artery wall, thereby restoring blood flow to the narrowed or blocked vessels. The image-guided procedure is often combined with the placement of either uncoated stents -- tiny expandable mesh devices- or stents coated with slowly-released antiproliferative ...
Tsukuba, Japan -- Economists have been using game theory to study decision-making since the 1950s. More recently, the interdisciplinary field of neuroeconomics has gained popularity as scientists try to understand how economic decisions are made in the brain. Researchers led by Professor Masayuki Matsumoto and Assistant Professor Hiroshi Yamada at the University of Tsukuba in Japan studied populations of neurons across the monkey brain reward network to find out where and when expected value is calculated.
The team trained monkeys to perform a lottery task for a reward. The monkeys saw two pie charts on a computer screen. The colors in the charts told the monkeys the size of the reward and the probability of getting it. ...
Black carbon (BC) is the product of incomplete combustion of fossil fuels, biofuel, and biomass. By strongly absorbing solar radiation, BC can heat the atmosphere, affect its stability, and further deteriorate air quality.
The climatic and environmental effects of BC are determined by its loading in the atmosphere. Scientists find that microphysical characteristics of BC, such as particle size and mixing state, can also influence these effects.
The team pointed out that the reduction of the thickly coated BC would further lead to a decline of solar radiation absorption by atmospheric aerosols, besides the decline resulting from the BC loading ...
Clostridioides difficile infection (rCDI) occurs in the gut and is caused by the Gram-positive, spore-forming anaerobic bacterium, C. difficile when its spores attach to fecal matter and are transferred from hand to mouth by health care workers. Patients undergoing antibiotic treatment are especially susceptible as the microorganisms that maintain a healthy gut are greatly damaged by the antibiotics.
Treatment of rCDI involves withdrawing the causative antibiotics and initiating antibiotic therapy, although this can be very challenging. Fecal microbiota transplantation (FMT) is considered an effective alternative therapy as it addresses the issue from the ground up by replacing the damaged microflora with a healthy one through a stool transplant.
However, two deaths caused by antibiotic-resistant ...
Plant nanosensors and Raman spectroscopy are two emerging analytical technologies and tools to study plants and monitor plant health, enabling research opportunities in plant science that have so far been difficult to achieve with conventional technologies such as genetic engineering techniques
The species-independent analytical tools are rapid and non-destructive, overcoming current limitations and providing a wealth of real-time information, such as early plant stress detection and hormonal signalling, that are important to plant growth and yield ...
The percept of time relates to the sense of touch. A new SISSA study "A sensory integration account for time perception" published in PLOS Computational Biology uncovers this connection. "The challenge to neuroscience posed by the sense of time lies, first and foremost, in the fact there do not exist dedicated receptors - the passage of time is a sensory experience constructed without sensors," notes Mathew Diamond, director of the Tactile Perception and Learning Lab. "One might imagine a precise clock in the brain, a sort of stopwatch that registers the start and stop and computes the elapsed ...
A University of Arizona Health Sciences study has estimated total lifetime costs at $736 million for the 10,359 valley fever patients diagnosed in Arizona in 2019, underscoring the economic burden the disease places on the state and its residents.
The prevalence of valley fever, formally known as coccidioidomycosis or cocci, has increased in recent years, from 5,624 cases diagnosed in Arizona in 2014 to 10,359 cases in 2019. There currently are no certain means of prevention or vaccination for the fungal disease, which is caused by spores of Coccidioides, a family of fungi found in soils of the Southwest.
The findings highlight the need ...
Feb. 10, 2021 - A new paper published online in the Annals of the American Thoracic Society describes a "virtual" recovery program for sepsis patients that may also help post-COVID-19 patients and survivors of other serious illnesses.
In " END ...
Scientists from Nanjing University and the University of Macau have devised a new approach to extend the survival of transplanted probiotics in vivo, enhancing the efficacy of cancer chemo-/immunotherapies in mice. The paper entitled "Smectite promotes probiotic biofilm formation in the gut for cancer immunotherapy" appears online today in Cell Reports.
The gut contains trillions of symbiotic bacteria. Disturbing the balance of intestinal flora may increase the occurrence of major diseases, including cancers. The gut microbiome plays an essential role in regulating the host immunity, which has inspired strategies to modulate intestinal microorganisms ...
