ALBERT

Description: How much of something do we need to keep people safe and well? This question is frequently asked by those working in risk management. Across diverse sectors from flood protection to health care, practitioners assess risk as the product of the impact of a given event and the probability of its occurrence. Although these estimates are often uncertain, policy-makers must ultimately make spending decisions aimed at averting these risks, because the costs of inaction to society can be substantial. Biodiversity loss is a similarly critical, yet uncertain, issue. On page 288 of this issue, Newbold et al. (1) quantify global biodiversity losses, providing much-needed information on the encroachment of proposed “safe limits.” Author: Tom H. Oliver

Description: Butterflies are better documented and monitored worldwide than any other nonpest taxon of insects (1). In the United Kingdom alone, volunteer recorders have sampled more than 750,000 km of repeat transects since 1976, equivalent to walking to the Moon and back counting butterflies (2). Such programs are revealing regional extinctions and population declines that began before 1900 (3, 4). In a recent study, Habel et al. report a similar story based on inventories of butterflies and burnet moths since 1840 in a protected area in Bavaria, Germany (5). The results reveal severe species losses: Scarce, specialized butterflies have largely disappeared, leaving ecosystems dominated by common generalist ones. Similar trends are seen across Europe (6) and beyond, with protected areas failing to conserve many species for which they were once famed. Author: Jeremy A. Thomas

Description: A new study suggests that common settings used in software for analyzing brain scans may lead to false positive results. Researchers led by Anders Eklund, an electrical engineer at Linköping University in Sweden, analyzed functional magnetic resonance imaging (fMRI) data from several public databases. Certain software settings, the team found, could give rise to a false positive result up to 70% of the time. In the context of a typical fMRI experiment, that could lead researchers to wrongly conclude that activity in a certain area of the brain plays a role in a cognitive function such as perception or memory. Author: Greg Miller

Description: Author: Stella M. Hurtley

Description: Author: Julia Fahrenkamp-Uppenbrink

Description: On 21 October 2013, the Italian phytosanitary service notified the European Commission (EC) that the plant pathogen Xylella fastidiosa had been detected in olive trees near Gallipoli, a tourist destination in Italy's southern region of Apulia (1). This xylem-limited bacterium is spread by insect vectors and causes disease in crops such as grapevines, citrus, coffee, and almond; various ornamentals; and trees such as oaks, elms, and sycamores. Because of the risks of X. fastidiosa being introduced, established, and spread throughout Europe, this species is a regulated quarantine pest. Yet, X. fastidiosa has been left unchecked and has marched northward, leaving destruction in its wake (see the photo) (2). The establishment of X. fastidiosa in Italy has been an agricultural, environmental, political, and cultural disaster. Author: Rodrigo P. P. Almeida

Description: Author: Julia Fahrenkamp-Uppenbrink

Description: Recent dives into Colombia's Cartagena Bay have revealed an unusually resilient coral reef thriving in the polluted waters. But the reef faces a threat: an end to Colombia's decades-long guerrilla war. The government is on the verge of inking a peace deal with its main adversary, the Revolutionary Armed Forces of Colombia, or FARC. Experts expect peace to lead to a development boom, threatening ecosystems all over the country with deforestation and runoff. A new shipping lane is planned for Cartagena Bay, and construction will mean dredging right through the reef. Researchers believe studying the reef's resiliency could help struggling corals around the world and are racing to collect samples before it's too late. Author: Lizzie Wade

Description: Early Victorian naturalists marveled at the profusion of diversity they encountered as they traveled from temperate to tropical latitudes. The inverse relationship between latitude and species richness that these naturalists first observed is now referred to as the latitudinal diversity gradient. Various ecological and evolutionary explanations have been proposed for the latitudinal diversity gradient. Of these, perhaps none are more relevant to contemporary conservation issues than Janzen's hypothesis of latitudinal differences in species' climatic tolerances and thermal selectivity (1). On page 1437 of this issue, Chan et al. (2) advance Janzen's early theories by elucidating some of the potential selective pressures imposed by climate and climate variability. Authors: Timothy M. Perez, James T. Stroud, Kenneth J. Feeley

Description: In 1492, Columbus encountered frigate birds while en route to the New World and noted that the bird “does not alight on the sea nor depart from land 20 leagues” (1). Columbus observed correctly that frigate birds do not land on the sea, but he severely underestimated how far some frigate birds fly from land. On page 74 of this issue, Weimerskirch et al. (2) show that great frigate birds (Fregata minor) reduce transit costs by riding strong thermal updrafts beneath or inside cumulus clouds and then gliding long distances to another thermal, searching for food along the way. By exploiting cumulus clouds and trade winds in the Indian Ocean, the birds forage around the doldrums, a largely windless zone. Authors: Raymond B. Huey, Curtis Deutsch

Description: Climate change affects wild plant species across their geographical ranges. Studies at the margins of species' ranges reveal upslope expansion, low-elevation range contraction, and, in some cases, a lack of geographic response to climate change (1). However, all populations, including those in the core of species' ranges, are subject to climate-driven natural selection that promotes adaptation to a warmer world (2). Theoretical models show that coupled spatial and temporal responses of populations can mediate the negative effects of climate change (3, 4), but it remains unclear whether these processes can occur fast enough to rescue populations from extinction (5). On page 69 of this issue, Petry et al. (6) report rapid spatial and temporal change in plant sex ratios in response to changing climatic conditions. These changes could facilitate geographic range shifts in the montane perennial herb valerian (Valeriana edulis). Authors: Julie R. Etterson, Susan J. Mazer

Description: New rules governing 1 million hectares of federal forestland in the Pacific Northwest are rekindling a bit of the old-growth timber wars of the late 20th century. The changes announced by the Bureau of Land Management (BLM) on 5 August have environmentalists charging that it rolls back important habitat protections contained in the 1994 Northwest Forest Plan. That plan severely curtailed logging on 10 million hectares of federal lands in the name of protecting forests and species, including the northern spotted owl. Meanwhile, Oregon counties that get timber revenue from BLM land charge that the agency is still restricting logging too much. Some scientists are siding with the environmental groups, whereas others say the new approach is an advance that rests on science that has emerged over the last 2 decades. The outcome of this debate could set the stage for changes by the U.S. Forest Service, which controls most of the land covered by the 1994 plan. Author: Warren Cornwall

Description: Degenerated retinas, globs of liver fat, wildly fluctuating blood sugar and insulin levels—all can spell trouble for people. But they are a way of life for Astyanax mexicanus, better known as the blind cave fish or Mexican tetra. For decades, biologists have studied these pale 6-centimeter-long fish to understand the ecological and evolutionary effects of subterranean life. Now, some researchers argue that the fishes' adaptations can shed light on human diseases including retinal degeneration and diabetes. And results presented last week at the 2016 International Conference on Subterranean Biology back up that view. The U.S. National Institutes of Health sees promise in cave fish as well, having agreed to fund the work of several cave fish biologists. Author: Elizabeth Pennisi

Description: Concerns over deforestation have led to attempts to identify suitable areas for reforestation around the world (1). The most ambitious effort to date is the World Resources Institute (WRI) Atlas of Forest and Landscape Restoration Opportunities (1). This map is linked to a global plan to reforest degraded lands to offset anthropogenic CO2 emissions. The immediate target is the reforestation of 1.5 million km2 by 2020 (2, 3). Vast areas of open grassy vegetation have been identified as suitable for reforestation. But are all these grasslands secondary products of deforestations? Recent research shows that grasslands are often ancient and highly biodiverse, but it remains difficult to distinguish between primary and secondary grasslands on a large scale. Reforestation efforts thus risk converting ancient tropical grasslands to plantations. Author: William J. Bond

Description: Author: Julia Fahrenkamp-Uppenbrink

Description: As you navigate a landscape, certain neurons in the brain fire at multiple locations, marking out a hexagonal grid on a mental map. The discovery of these so-called grid cells, and their role as a neuronal GPS for spatial navigation, won the 2014 Nobel Prize in Physiology or Medicine for Norwegian scientists Edvard Moser and May-Britt Moser. Now, it seems that the brain may make maps of abstract realms, too. On p. 1464, a team at the University of Oxford provides evidence that gridlike neuronal activity throughout the brain helps people organize nonnavigation knowledge—for the purposes of the new study, differences in body shape between various types of birds. Author: Emily Underwood

Description: Soil microorganisms are central to the provision of food, feed, fiber, and medicine. Engineering of soil microbiomes may promote plant growth and plant health, thus contributing to food security and agricultural sustainability (1, 2). However, little is known about most soil microorganisms and their impact on plant health. Disease-suppressive soils offer microbiome-mediated protection of crop plants against infections by soil-borne pathogens. Understanding of the microbial consortia and mechanisms involved in disease suppression may help to better manage plants while reducing fertilizer and pesticide inputs. Authors: Jos M. Raaijmakers, Mark Mazzola

Description: Author: Wei Wong

Description: Author: Julia Fahrenkamp-Uppenbrink

Description: History tells us that the motivation for new environmental policy is much stronger when there is demonstrated ecological impact. Multinational agreements to stop the use of DDT followed the precipitous decline of predatory bird populations. Similarly, decisions to regulate emissions to prevent acid rain followed widespread degradation of aquatic habitats. Ideally, environmental policy should be catalyzed by scientific evidence rather than environmental catastrophe. As scientists, we can do our part by providing evidence that is relevant to the natural environment. On page 1213 of this issue, Lönnstedt and Eklöv (1) take an important step forward in this regard by reporting ecologically relevant evidence on a growing environmental issue: microplastic pollution. Author: Chelsea M. Rochman

Description: Author: Peter Stern

Description: Author: Leslie K. Ferrarelli

Description: The specter of neurodegenerative disease, particularly Alzheimer's disease, haunts the developed world and exacts a poorly documented toll on underdeveloped countries. With so little progress made toward finding a cure—or, better, a prevention—it is time to rethink the path to progress. This requires a change in perspective on the type of research that will make a difference. The lesson learned from cancer research is that a new commitment means rethinking the fundamental approach to the disease. Cancer research moved from taking potshots with, usually, cytotoxic drugs to a bottom-up, mechanism-based approach in which newly acquired genetic knowledge played the largest role. Today, that effort has produced a platform of knowledge from which academia and industry are drawing. For neurodegenerative disease, the genetic approach remains valid but the problem must concurrently be approached from a complementary, robust cell biological perspective, focusing on the cellular cascade of events that lead to neuronal cell death. Authors: K. S. Kosik, T. J. Sejnowski, M. E. Raichle, A. Ciechanover, D. Baltimore

Description: Temporal lobe epilepsy (TLE) is characterized by debilitating, recurring seizures and an increased risk for cognitive deficits. Mossy cells (MCs) are key neurons in the hippocampal excitatory circuit, and the partial loss of MCs is a major hallmark of TLE. We investigated how MCs contribute to spontaneous ictal activity and to spatial contextual memory in a mouse model of TLE with hippocampal sclerosis, using a combination of optogenetic, electrophysiological, and behavioral approaches. In chronically epileptic mice, real-time optogenetic modulation of MCs during spontaneous hippocampal seizures controlled the progression of activity from an electrographic to convulsive seizure. Decreased MC activity is sufficient to impede encoding of spatial context, recapitulating observed cognitive deficits in chronically epileptic mice.

Description: Ecologists have shown through hundreds of experiments that ecological communities with more species produce higher levels of essential ecosystem functions such as biomass production, nutrient cycling, and pollination, but whether this finding holds in nature (that is, in large-scale and unmanipulated systems) is controversial. This knowledge gap is troubling because ecosystem services have been widely adopted as a justification for global biodiversity conservation. Here we show that, to provide crop pollination in natural systems, the number of bee species must increase by at least one order of magnitude compared with that in field experiments. This increase is driven by species turnover and its interaction with functional dominance, mechanisms that emerge only at large scales. Our results show that maintaining ecosystem services in nature requires many species, including relatively rare ones.

Description: Billions of animals cross the globe each year during seasonal migrations, but efforts to monitor them are hampered by the unpredictability of their movements. We developed a bird migration forecast system at a continental scale by leveraging 23 years of spring observations to identify associations between atmospheric conditions and bird migration intensity. Our models explained up to 81% of variation in migration intensity across the United States at altitudes of 0 to 3000 meters, and performance remained high in forecasting events 1 to 7 days in advance (62 to 76% of variation was explained). Avian migratory movements across the United States likely exceed 500 million individuals per night during peak passage. Bird migration forecasts will reduce collisions with buildings, airplanes, and wind turbines; inform a variety of monitoring efforts; and engage the public.

Description: Nie and colleagues suggest a key role for interannual climate variation as an explanation for the temporal dynamics of an unexpected 20-year reversal of biomass responses of C 3 -C 4 grasses to elevated CO 2 . However, we had already identified some climate-dependent differences in C 3 and C 4 responses to eCO 2 and shown that these could not fully explain the temporal dynamics we observed.

Description: Biodiversity experiments have shown that species loss reduces ecosystem functioning in grassland. To test whether this result can be extrapolated to forests, the main contributors to terrestrial primary productivity, requires large-scale experiments. We manipulated tree species richness by planting more than 150,000 trees in plots with 1 to 16 species. Simulating multiple extinction scenarios, we found that richness strongly increased stand-level productivity. After 8 years, 16-species mixtures had accumulated over twice the amount of carbon found in average monocultures and similar amounts as those of two commercial monocultures. Species richness effects were strongly associated with functional and phylogenetic diversity. A shrub addition treatment reduced tree productivity, but this reduction was smaller at high shrub species richness. Our results encourage multispecies afforestation strategies to restore biodiversity and mitigate climate change.

Description: Glia constitute roughly half of the cells of the central nervous system (CNS) but were long-considered to be static bystanders to its formation and function. Here we provide an overview of how the diverse and dynamic functions of glial cells orchestrate essentially all aspects of nervous system formation and function. Radial glia, astrocytes, oligodendrocyte progenitor cells, oligodendrocytes, and microglia each influence nervous system development, from neuronal birth, migration, axon specification, and growth through circuit assembly and synaptogenesis. As neural circuits mature, distinct glia fulfill key roles in synaptic communication, plasticity, homeostasis, and network-level activity through dynamic monitoring and alteration of CNS structure and function. Continued elucidation of glial cell biology, and the dynamic interactions of neurons and glia, will enrich our understanding of nervous system formation, health, and function.

Description: To understand how neurons assemble to form functional circuits, it is necessary to obtain a detailed knowledge of their diversity and to define the developmental specification programs that give rise to this diversity. Invertebrates and vertebrates appear to share common developmental principles of neuronal specification in which cascades of transcription factors temporally pattern progenitors, while spatial cues modify the outcomes of this temporal patterning. Here, we highlight these conserved mechanisms and describe how they are used in distinct neural structures. We present the questions that remain for a better understanding of neuronal specification. Single-cell RNA profiling approaches will potentially shed light on these questions, allowing not only the characterization of neuronal diversity in adult brains, but also the investigation of the developmental trajectories leading to the generation and maintenance of this diversity.

Description: Which memories are retained, where, and in what form depends on a long afterlife of the acquired information in the brain. Initial steps of consolidation may be completed within a few hours during wakefulness, but other forms of postacquisition processing take longer, extending into sleep (1, 2). The relationship between brain activity during sleep and memory consolidation remains controversial and poorly understood. On page 812 of this issue, Boyce et al. (3) demonstrate that a distinct form of hippocampal neural activity, called theta oscillation, is critical for memory formation during the rapid eye movement (REM) phase of sleep. Author: Bernat Kocsis

Description: Last week, at the Sixth Annual Traumatic Brain Injury Conference in Arlington, Virginia, neurologist Samuel Gandy presented a former National Football League player's positron emission tomography (PET) scan as the "most dramatic" evidence yet of chronic traumatic encephalopathy (CTE) in a living person. "I've never seen anything like it," he said of the scan, which used a PET tracer called T807 to reveal deposits of a sticky, helical protein called tau in the player's brain. The announcement could represent a milestone for tau imaging, a promising but controversial strategy for diagnosing neurodegenerative diseases such as Alzheimer's in living patients. If the science pans out, it could also transform the medical and legal status of CTE, which at present can only be officially diagnosed after death, when a pathologist looks for tau in brain tissue. Author: Emily Underwood

Description: Earlier this month, György Buzsáki of New York University in New York City showed a slide that sent a murmur through an audience in the Grand Ballroom of New York's Midtown Hilton during the annual meeting of the Cognitive Neuroscience Society. It wasn't just the grisly image of a human cadaver with more than 200 electrodes inserted into its brain that set people whispering; it was what those electrodes detected—or rather, what they failed to detect. When Buzsáki and his colleague, Antal Berényi of the University of Szeged in Hungary, mimicked an increasingly popular form of brain stimulation by applying alternating electrical current to the outside of the cadaver's skull, the electrodes inside registered little. Hardly any current entered the brain. On closer study, the pair discovered that up to 90% of the current had been redirected by the skin covering the skull, which acted as a "shunt," Buzsáki said. For many meeting attendees, the unusual study heightened serious doubts about the mechanism and effectiveness of transcranial direct current stimulation, an experimental, noninvasive treatment that uses electrodes to deliver weak current to a person's scalp or forehead. Author: Emily Underwood

Description: Author: Leslie K. Ferrarelli

Description: The worldwide human obesity epidemic has provoked a great deal of experimentation to understand the biological controls of energy expenditure and food intake, two processes that together determine energy balance. Because food intake relies on feeding behavior that is determined by the brain, studies have focused on how the central nervous system receives and behaviorally responds to signals of metabolic status. On page 1293 of this issue, Lagerlöf et al. (1) report that a glycosylation enzyme serves as a neuronal nutrient sensor that is critical in the control of food intake and body weight. Author: Gary J. Schwartz

Description: Imagine a chain of uninterrupted wild landscapes spanning the savannas and forests of southern and central Africa, the woodlands of Poland and Belarus, and the tropical forests of Central and South America. By committing half of the planet's terrestrial and marine surface to nature, Edward O. Wilson believes that we can save millions of species, as well as humanity. This is Wilson's audacious proposal to stave off the coming biological apocalypse, the sixth mass extinction event, which he outlines in Half-Earth: Our Planet's Fight for Life. Author: Christine J. Griffiths

Description: Contrary to classical economic supposition (1), understanding people's preferences and decisions is not as simple as observing their actions. Indeed, there are many reasons for behaving altruistically, such as being moved by someone's suffering (empathy) or feeling obliged to return a favor (reciprocity) (2, 3). One of the major challenges for social psychologists and neuroscientists is to characterize the different motives underlying our interactions with other people. On page 1074 in this issue, Hein et al. (4) show that knowing how distinct areas in the human brain communicate with each other can tell us why someone behaves altruistically. Authors: Sebastian Gluth, Laura Fontanesi

Description: Humans have long used animals as sentinels for threats to their own well-being. Canaries in coal mines are a classic example. On a global scale, studies of birds were key to detecting environmental problems caused by the excessive use of pesticides (1, 2). The recent loss of up to 98% of some vulture populations highlights the widespread dangerous effects of diclofenac use in cattle (3). Bee populations, sentinels for global insect losses, are also declining owing to the combined stress from pesticides and other environmental changes caused by humans, resulting in a widespread loss of pollination services (4). On page 819 of this issue, van Gils et al. (5) highlight another global ecological warning sign, this time linked to Arctic warming. They show that long-term changes in the body architecture of Arctic wading birds can affect their survival in their tropical wintering range. Authors: Martin Wikelski, Grigori Tertitski

Description: Brain electrical activity differs markedly between wakefulness and sleep. Concomitant shifts in the ion composition of brain extracellular fluids were thought to be a consequence rather than a cause of the sleep-wake–dependent changes in neuronal activity. On page 550 of this issue, Ding et al. (1) report the surprising observation that ionic changes in the extracellular fluid are a potent control of sleep-wake–dependent neuronal activity. Authors: Hans-Peter Landolt, Sebastian C. Holst

Description: Even as recently as early March, Australian coral reef scientists still hoped that the legendary Great Barrier Reef (GBR) would get off lightly in the current El Niño, the climate phenomenon that brings unusually warm water to the equatorial Pacific, stressing and often killing corals. No such luck. On 20 March, the GBR Marine Park Authority in Townsville, Australia, reported that divers were finding extensive coral bleaching—the loss of symbiotic algae—in remote northern areas of the reef. Many sections were already dead. Subsequent flyover surveys have confirmed an unfolding disaster, with only four of 520 reefs appearing unscathed. The GBR joins a lengthening list of reefs bleached because of the El Niño that started in late 2014. It is now the longest bleaching event ever, and many more corals worldwide will likely die. Author: Dennis Normile

Description: Neuroscience is becoming big science, with the 2013 launches of the European Union's Human Brain Project and the United States's Brain Research through Advancing Innovative Neurotechnology (BRAIN) initiative leading the way. Last week, leaders of these massive, multi-institution projects and others around the world met at Johns Hopkins University in Baltimore, Maryland, to discuss an even loftier goal: a global neuroscience collaboration that would link their efforts and rival big science investments in astronomy and physics. More than 60 neuroscientists from 12 countries pitched diverse visions for such a project at the meeting, sponsored by the Kavli Foundation and the National Science Foundation. Author: Emily Underwood

Description: Almost all land plants, including most trees, shrubs, and herbs, form symbiotic associations with mycorrhizal fungi (1). These soil fungi acquire nutrients that they transfer to their plant hosts in exchange for carbon (see the photo). Plants in natural vegetation can acquire up to 80% of nitrogen and phosphorus from their mycorrhizal associates (2). Individual mycorrhizal fungi can simultaneously colonize many plant hosts of the same species or different species. As a result, plants in natural communities are interconnected by mycorrhizal networks. Earlier studies with small tree seedlings revealed that carbon is transferred from one plant to another through these underground mycorrhizal pipelines (3). On page 342 of this issue, Klein et al. (4) show that interplant carbon transfer is not confined to tree seedlings. Author: Marcel G. A. van der Heijden

Description: Clinical observations indicate that the paramedian region of the thalamus is a critical node for controlling wakefulness. However, the specific nucleus and neural circuitry for this function remain unknown. Using in vivo fiber photometry or multichannel electrophysiological recordings in mice, we found that glutamatergic neurons of the paraventricular thalamus (PVT) exhibited high activities during wakefulness. Suppression of PVT neuronal activity caused a reduction in wakefulness, whereas activation of PVT neurons induced a transition from sleep to wakefulness and an acceleration of emergence from general anesthesia. Moreover, our findings indicate that the PVT–nucleus accumbens projections and hypocretin neurons in the lateral hypothalamus to PVT glutamatergic neurons’ projections are the effector pathways for wakefulness control. These results demonstrate that the PVT is a key wakefulness-controlling nucleus in the thalamus.

Description: The salience of behaviorally relevant stimuli is dynamic and influenced by internal state and external environment. Monitoring such changes is critical for effective learning and flexible behavior, but the neuronal substrate for tracking the dynamics of stimulus salience is obscure. We found that neurons in the paraventricular thalamus (PVT) are robustly activated by a variety of behaviorally relevant events, including novel ("unfamiliar") stimuli, reinforcing stimuli and their predicting cues, as well as omission of the expected reward. PVT responses are scaled with stimulus intensity and modulated by changes in homeostatic state or behavioral context. Inhibition of the PVT responses suppresses appetitive or aversive associative learning and reward extinction. Our findings demonstrate that the PVT gates associative learning by providing a dynamic representation of stimulus salience.

Description: Animals constantly update their body posture to meet behavioral demands, but little is known about the neural signals on which this depends. We therefore tracked freely foraging rats in three dimensions while recording from the posterior parietal cortex (PPC) and the frontal motor cortex (M2), areas critical for movement planning and navigation. Both regions showed strong tuning to posture of the head, neck, and back, but signals for movement were much less dominant. Head and back representations were organized topographically across the PPC and M2, and more neurons represented postures that occurred less often. Simultaneous recordings across areas were sufficiently robust to decode ongoing behavior and showed that spiking in the PPC tended to precede that in M2. Both the PPC and M2 strongly represent posture by using a spatially organized, energetically efficient population code.

Description: Memory resides in engram cells distributed across the brain. However, the site-specific substrate within these engram cells remains theoretical, even though it is generally accepted that synaptic plasticity encodes memories. We developed the dual-eGRASP (green fluorescent protein reconstitution across synaptic partners) technique to examine synapses between engram cells to identify the specific neuronal site for memory storage. We found an increased number and size of spines on CA1 engram cells receiving input from CA3 engram cells. In contextual fear conditioning, this enhanced connectivity between engram cells encoded memory strength. CA3 engram to CA1 engram projections strongly occluded long-term potentiation. These results indicate that enhanced structural and functional connectivity between engram cells across two directly connected brain regions forms the synaptic correlate for memory formation.

Description: In an era of massive biodiversity loss, the greatest conservation success story has been the growth of protected land globally. Protected areas are the primary defense against biodiversity loss, but extensive human activity within their boundaries can undermine this. Using the most comprehensive global map of human pressure, we show that 6 million square kilometers (32.8%) of protected land is under intense human pressure. For protected areas designated before the Convention on Biological Diversity was ratified in 1992, 55% have since experienced human pressure increases. These increases were lowest in large, strict protected areas, showing that they are potentially effective, at least in some nations. Transparent reporting on human pressure within protected areas is now critical, as are global targets aimed at efforts required to halt biodiversity loss.

Description: LaManna et al . (Reports, 30 June 2017, p. 1389) found higher conspecific negative density dependence in tree communities at lower latitudes, yielding a possible mechanistic explanation for the latitudinal diversity gradient. We show that their results are artifacts of a selective data transformation and a forced zero intercept in their fitted model. A corrected analysis shows no latitudinal trend.

Description: Chisholm and Fung claim that our method of estimating conspecific negative density dependence (CNDD) in recruitment is systematically biased, and present an alternative method that shows no latitudinal pattern in CNDD. We demonstrate that their approach produces strongly biased estimates of CNDD, explaining why they do not detect a latitudinal pattern. We also address their methodological concerns using an alternative distance-weighted approach, which supports our original findings of a latitudinal gradient in CNDD and a latitudinal shift in the relationship between CNDD and species abundance.

Description: Consolidation of spatial and episodic memories is thought to rely on replay of neuronal activity sequences during sleep. However, the network dynamics underlying the initial storage of memories during wakefulness have never been tested. Although slow, behavioral time scale sequences have been claimed to sustain sequential memory formation, fast ("theta") time scale sequences, nested within slow sequences, could be instrumental. We found that in rats traveling passively on a model train, place cells formed behavioral time scale sequences but theta sequences were degraded, resulting in impaired subsequent sleep replay. In contrast, when the rats actively ran on a treadmill while being transported on the train, place cells generated clear theta sequences and accurate trajectory replay during sleep. Our results support the view that nested sequences underlie the initial formation of memory traces subsequently consolidated during sleep.

Description: Sabo et al . (Research Articles, 8 December 2017, p. 1270) use sophisticated analyses of flow and fishery data from the Lower Mekong Basin to design a "good" hydrograph that, if implemented by planned hydropower dams, would increase the catch by a factor of 3.7. However, the hydrograph is not implementable, and, if it were, it would devastate the fishery. Further, the analyses are questionable.

Description: Whether fear attenuation is mediated by inhibition of the original memory trace of fear with a new memory trace of safety or by updating of the original fear trace toward safety has been a long-standing question in neuroscience and psychology alike. In particular, which of the two scenarios underlies the attenuation of remote (month-old) fear memories is completely unknown, despite the impetus to better understand this process against the backdrop of enduring traumata. We found—chemogenetically and in an engram-specific manner—that effective remote fear attenuation is accompanied by the reactivation of memory recall–induced neurons in the dentate gyrus and that the continued activity of these neurons is critical for fear reduction. This suggests that the original memory trace of fear actively contributes to remote fear attenuation.

Description: Glycerophospholipids, the structural components of cell membranes, have not been considered to be spatial cues for intercellular signaling because of their ubiquitous distribution. We identified lyso-phosphatidyl-beta-D-glucoside (LysoPtdGlc), a hydrophilic glycerophospholipid, and demonstrated its role in modality-specific repulsive guidance of spinal cord sensory axons. LysoPtdGlc is locally synthesized and released by radial glia in a patterned spatial distribution to regulate the targeting of nociceptive but not proprioceptive central axon projections. Library screening identified the G protein-coupled receptor GPR55 as a high-affinity receptor for LysoPtdGlc, and GPR55 deletion or LysoPtdGlc loss of function in vivo caused the misallocation of nociceptive axons into proprioceptive zones. These findings show that LysoPtdGlc/GPR55 is a lipid-based signaling system in glia-neuron communication for neural development.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Guy, Adam T -- Nagatsuka, Yasuko -- Ooashi, Noriko -- Inoue, Mariko -- Nakata, Asuka -- Greimel, Peter -- Inoue, Asuka -- Nabetani, Takuji -- Murayama, Akiho -- Ohta, Kunihiro -- Ito, Yukishige -- Aoki, Junken -- Hirabayashi, Yoshio -- Kamiguchi, Hiroyuki -- New York, N.Y. -- Science. 2015 Aug 28;349(6251):974-7. doi: 10.1126/science.aab3516.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. ; RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. Lipid Biology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. ; Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Sendai, Miyagi 980-8578, Japan. Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology (PRESTO), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan. ; Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan. ; Synthetic Cellular Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. ; Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Sendai, Miyagi 980-8578, Japan. Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), 1-7-1 Otemachi, Chiyoda, Tokyo 100-0004, Japan. ; RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. kamiguchi@brain.riken.jp hirabaya@riken.jp.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26315437" target="_blank"〉PubMed〈/a〉

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Reczek, Colleen R -- Chandel, Navdeep S -- New York, N.Y. -- Science. 2015 Dec 11;350(6266):1317-8. doi: 10.1126/science.aad8671.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine and Robert H. Lurie Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. ; Department of Medicine and Robert H. Lurie Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. nav@northwestern.edu.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26659042" target="_blank"〉PubMed〈/a〉

Description: Double-stranded RNAs (dsRNAs) targeted against essential genes can trigger a lethal RNA interference (RNAi) response in insect pests. The application of this concept in plant protection is hampered by the presence of an endogenous plant RNAi pathway that processes dsRNAs into short interfering RNAs. We found that long dsRNAs can be stably produced in chloroplasts, a cellular compartment that appears to lack an RNAi machinery. When expressed from the chloroplast genome, dsRNAs accumulated to as much as 0.4% of the total cellular RNA. Transplastomic potato plants producing dsRNAs targeted against the beta-actin gene of the Colorado potato beetle, a notorious agricultural pest, were protected from herbivory and were lethal to its larvae. Thus, chloroplast expression of long dsRNAs can provide crop protection without chemical pesticides.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Jiang -- Khan, Sher Afzal -- Hasse, Claudia -- Ruf, Stephanie -- Heckel, David G -- Bock, Ralph -- New York, N.Y. -- Science. 2015 Feb 27;347(6225):991-4. doi: 10.1126/science.1261680.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max-Planck-Institut fur Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany. ; Max-Planck-Institut fur Chemische Okologie, D-07745 Jena, Germany. ; Max-Planck-Institut fur Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany. rbock@mpimp-golm.mpg.de.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25722411" target="_blank"〉PubMed〈/a〉

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bernstein, Rachel -- New York, N.Y. -- Science. 2015 Apr 17;348(6232):269. doi: 10.1126/science.348.6232.269.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25883332" target="_blank"〉PubMed〈/a〉

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hackett, Perry -- Carroll, Dana -- P01 HD032652/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 2015 Mar 20;347(6228):1324. doi: 10.1126/science.347.6228.1324.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Genetics, Cell Biology, and Development, Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA. hacke004@umn.edu. ; Department of Biochemistry, School of Medicine, University of Utah, Salt Lake City, UT 84112, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25792322" target="_blank"〉PubMed〈/a〉

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dajani, Rana -- New York, N.Y. -- Science. 2015 Nov 27;350(6264):1043. doi: 10.1126/science.350.6264.1043-b.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology and Biotechnology, Hashemite University, Zarqa, Jordan. rdajani@hu.edu.jo.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26612944" target="_blank"〉PubMed〈/a〉

Description: The RNA-guided CRISPR-associated protein Cas9 is used for genome editing, transcriptional modulation, and live-cell imaging. Cas9-guide RNA complexes recognize and cleave double-stranded DNA sequences on the basis of 20-nucleotide RNA-DNA complementarity, but the mechanism of target searching in mammalian cells is unknown. Here, we use single-particle tracking to visualize diffusion and chromatin binding of Cas9 in living cells. We show that three-dimensional diffusion dominates Cas9 searching in vivo, and off-target binding events are, on average, short-lived (〈1 second). Searching is dependent on the local chromatin environment, with less sampling and slower movement within heterochromatin. These results reveal how the bacterial Cas9 protein interrogates mammalian genomes and navigates eukaryotic chromatin structure.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Knight, Spencer C -- Xie, Liangqi -- Deng, Wulan -- Guglielmi, Benjamin -- Witkowsky, Lea B -- Bosanac, Lana -- Zhang, Elisa T -- El Beheiry, Mohamed -- Masson, Jean-Baptiste -- Dahan, Maxime -- Liu, Zhe -- Doudna, Jennifer A -- Tjian, Robert -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2015 Nov 13;350(6262):823-6. doi: 10.1126/science.aac6572.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of California, Berkeley, CA, USA. ; Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. ; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA. Transcriptional Imaging Consortium, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA. ; Laboratoire Physico-Chimie Curie, Institut Curie, Centre National de la Recherche Scientifique UMR 168, Paris, France. ; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA. ; Transcriptional Imaging Consortium, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA. Laboratoire Physico-Chimie Curie, Institut Curie, Centre National de la Recherche Scientifique UMR 168, Paris, France. ; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA. Transcriptional Imaging Consortium, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA. liuz11@janelia.hhmi.org doudna@berkeley.edu jmlim@berkeley.edu. ; Department of Chemistry, University of California, Berkeley, CA, USA. Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. Innovative Genomics Initiative, University of California, Berkeley, CA, USA. liuz11@janelia.hhmi.org doudna@berkeley.edu jmlim@berkeley.edu. ; Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA. Transcriptional Imaging Consortium, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA. Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. Li Ka Shing Biomedical and Health Sciences Center, University of California, Berkeley, CA, USA. liuz11@janelia.hhmi.org doudna@berkeley.edu jmlim@berkeley.edu.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26564855" target="_blank"〉PubMed〈/a〉

Description: Transcriptional regulation and posttranscriptional processing underlie many cellular and organismal phenotypes. We used RNA sequence data generated by Genotype-Tissue Expression (GTEx) project to investigate the patterns of transcriptome variation across individuals and tissues. Tissues exhibit characteristic transcriptional signatures that show stability in postmortem samples. These signatures are dominated by a relatively small number of genes-which is most clearly seen in blood-though few are exclusive to a particular tissue and vary more across tissues than individuals. Genes exhibiting high interindividual expression variation include disease candidates associated with sex, ethnicity, and age. Primary transcription is the major driver of cellular specificity, with splicing playing mostly a complementary role; except for the brain, which exhibits a more divergent splicing program. Variation in splicing, despite its stochasticity, may play in contrast a comparatively greater role in defining individual phenotypes.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4547472/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4547472/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mele, Marta -- Ferreira, Pedro G -- Reverter, Ferran -- DeLuca, David S -- Monlong, Jean -- Sammeth, Michael -- Young, Taylor R -- Goldmann, Jakob M -- Pervouchine, Dmitri D -- Sullivan, Timothy J -- Johnson, Rory -- Segre, Ayellet V -- Djebali, Sarah -- Niarchou, Anastasia -- GTEx Consortium -- Wright, Fred A -- Lappalainen, Tuuli -- Calvo, Miquel -- Getz, Gad -- Dermitzakis, Emmanouil T -- Ardlie, Kristin G -- Guigo, Roderic -- HHSN261200800001E/PHS HHS/ -- HHSN268201000029C/HL/NHLBI NIH HHS/ -- HHSN268201000029C/PHS HHS/ -- R01 DA006227-17/DA/NIDA NIH HHS/ -- R01 MH090936/MH/NIMH NIH HHS/ -- R01 MH090941/MH/NIMH NIH HHS/ -- New York, N.Y. -- Science. 2015 May 8;348(6235):660-5. doi: 10.1126/science.aaa0355.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Harvard Department of stem cell and regenerative biology, Harvard University, Cambridge, MA, USA. ; Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland. Institute for Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland. Swiss Institute of Bioinformatics, Geneva, Switzerland. ; Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Facultat de Biologia, Universitat de Barcelona (UB), Barcelona, Catalonia, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain. ; Broad Institute of MIT and Harvard, Cambridge, MA, USA. ; Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain. McGill University, Montreal, Canada. ; Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain. National Institute for Scientific Computing (LNCC), Petropolis, Rio de Janeiro, Brazil. ; Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain. Radboud University, Nijmegen, Netherlands. ; Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain. Faculty of Bioengineering and Bioinformatics, Moscow State University, Leninskie Gory 1-73, 119992 Moscow, Russia. ; Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain. ; Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland. Institute for Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland. Swiss Institute of Bioinformatics, Geneva, Switzerland. ; Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Harvard Department of stem cell and regenerative biology, Harvard University, Cambridge, MA, USA. Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland. Institute for Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland. Swiss Institute of Bioinformatics, Geneva, Switzerland. Facultat de Biologia, Universitat de Barcelona (UB), Barcelona, Catalonia, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain. Broad Institute of MIT and Harvard, Cambridge, MA, USA. McGill University, Montreal, Canada. National Institute for Scientific Computing (LNCC), Petropolis, Rio de Janeiro, Brazil. Radboud University, Nijmegen, Netherlands. Faculty of Bioengineering and Bioinformatics, Moscow State University, Leninskie Gory 1-73, 119992 Moscow, Russia. North Carolina State University, Raleigh, NC, USA. New York Genome Center, New York, NY, USA. Department of Systems Biology, Columbia University, New York, NY, USA. Cancer Center and Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA. Institut Hospital del Mar d'Investigacions Mediques (IMIM), Barcelona, Catalonia, Spain. Joint CRG-Barcelona Super Computing Center (BSC)-Institut de Recerca Biomedica (IRB) Program in Computational Biology, Barcelona, Catalonia, Spain. ; North Carolina State University, Raleigh, NC, USA. ; Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland. Institute for Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland. Swiss Institute of Bioinformatics, Geneva, Switzerland. New York Genome Center, New York, NY, USA. Department of Systems Biology, Columbia University, New York, NY, USA. ; Facultat de Biologia, Universitat de Barcelona (UB), Barcelona, Catalonia, Spain. ; Broad Institute of MIT and Harvard, Cambridge, MA, USA. Cancer Center and Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA. ; Broad Institute of MIT and Harvard, Cambridge, MA, USA. kardlie@broadinstitute.org roderic.guigo@crg.cat. ; Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain. Institut Hospital del Mar d'Investigacions Mediques (IMIM), Barcelona, Catalonia, Spain. Joint CRG-Barcelona Super Computing Center (BSC)-Institut de Recerca Biomedica (IRB) Program in Computational Biology, Barcelona, Catalonia, Spain. kardlie@broadinstitute.org roderic.guigo@crg.cat.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25954002" target="_blank"〉PubMed〈/a〉

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bernstein, Rachel -- New York, N.Y. -- Science. 2015 Feb 6;347(6222):686. doi: 10.1126/science.347.6222.686. Epub 2015 Feb 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Rachel Bernstein is a staf writer for Science Careers. For more on life and careers, visit www.sciencecareers.org. Send your story to SciCareerEditor@aaas.org.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25657252" target="_blank"〉PubMed〈/a〉

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dantzer, Ben -- New York, N.Y. -- Science. 2015 Feb 20;347(6224):822-3. doi: 10.1126/science.aaa6480.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Psychology and Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA. dantzer@umich.edu.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25700499" target="_blank"〉PubMed〈/a〉

Description: A new docodontan mammaliaform from the Middle Jurassic of China has skeletal features for climbing and dental characters indicative of an omnivorous diet that included plant sap. This fossil expands the range of known locomotor adaptations in docodontans to include climbing, in addition to digging and swimming. It further shows that some docodontans had a diet with a substantial herbivorous component, distinctive from the faunivorous diets previously reported in other members of this clade. This reveals a greater ecological diversity in an early mammaliaform clade at a more fundamental taxonomic level not only between major clades as previously thought.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Meng, Qing-Jin -- Ji, Qiang -- Zhang, Yu-Guang -- Liu, Di -- Grossnickle, David M -- Luo, Zhe-Xi -- New York, N.Y. -- Science. 2015 Feb 13;347(6223):764-8. doi: 10.1126/science.1260879.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Beijing Museum of Natural History, Beijing 100050 China. ; Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China. ; Committee on Evolutionary Biology, The University of Chicago, Chicago, IL 60637, USA. ; Committee on Evolutionary Biology, The University of Chicago, Chicago, IL 60637, USA. Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, IL 60637, USA. zxluo@uchicago.edu.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25678661" target="_blank"〉PubMed〈/a〉

Description: Sex determination in the mosquito Aedes aegypti is governed by a dominant male-determining factor (M factor) located within a Y chromosome-like region called the M locus. Here, we show that an M-locus gene, Nix, functions as an M factor in A. aegypti. Nix exhibits persistent M linkage and early embryonic expression, two characteristics required of an M factor. Nix knockout with clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 resulted in largely feminized genetic males and the production of female isoforms of two key regulators of sexual differentiation: doublesex and fruitless. Ectopic expression of Nix resulted in genetic females with nearly complete male genitalia. Thus, Nix is both required and sufficient to initiate male development. This study provides a foundation for mosquito control strategies that convert female mosquitoes into harmless males.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hall, Andrew Brantley -- Basu, Sanjay -- Jiang, Xiaofang -- Qi, Yumin -- Timoshevskiy, Vladimir A -- Biedler, James K -- Sharakhova, Maria V -- Elahi, Rubayet -- Anderson, Michelle A E -- Chen, Xiao-Guang -- Sharakhov, Igor V -- Adelman, Zach N -- Tu, Zhijian -- AI113643/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 2015 Jun 12;348(6240):1268-70. doi: 10.1126/science.aaa2850. Epub 2015 May 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA. Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA. Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, USA. ; Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, USA. Department of Entomology, Virginia Tech, Blacksburg, VA, USA. ; Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA. Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, USA. ; Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA. ; School of Public Health and Tropical Medicine, Southern Medical University, Guangdong, People's Republic of China. ; Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA. Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, USA. Department of Entomology, Virginia Tech, Blacksburg, VA, USA. ; Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA. Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, USA. Department of Entomology, Virginia Tech, Blacksburg, VA, USA. jaketu@vt.edu zachadel@vt.edu. ; Interdisciplinary PhD Program in Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA. Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA. Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, USA. jaketu@vt.edu zachadel@vt.edu.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25999371" target="_blank"〉PubMed〈/a〉