78 research outputs found
Parent of origin genetic effects on methylation in humans are common and influence complex trait variation
Parent-of-origin effects (POE) are observed when there are different effects from alleles inherited from the two parents on phenotypic measures. Here, Zeng et al. study POE on DNA methylation in 5,101 individuals and identify genetic variants that associate with methylation variation via POE and their potential phenotypic consequences
Duck (Anas platyrhynchos) linkage mapping by AFLP fingerprinting
Amplified fragment length polymorphism (AFLP) with multicolored fluorescent molecular markers was used to analyze duck (Anas platyrhynchos) genomic DNA and to construct the first AFLP genetic linkage map. These markers were developed and genotyped in 766 F2 individuals from six families from a cross between two different selected duck lines, brown Tsaiya and Pekin. Two hundred and ninety-six polymorphic bands (64% of all bands) were detected using 18 pairs of fluorescent TaqI/EcoRI primer combinations. Each primer set produced a range of 7 to 29 fragments in the reactions, and generated on average 16.4 polymorphic bands. The AFLP linkage map included 260 co-dominant markers distributed in 32 linkage groups. Twenty-one co-dominant markers were not linked with any other marker. Each linkage group contained three to 63 molecular markers and their size ranged between 19.0 cM and 171.9 cM. This AFLP linkage map provides important information for establishing a duck chromosome map, for mapping quantitative trait loci (QTL mapping) and for breeding applications
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Predicting range shifts for critically endangered plants : is habitat connectivity irrelevant or necessary?
Climate and land-cover change will directly impact future species distributions, leading to range expansions, contractions and local extinctions. However, assessments of future range shifts rarely account for the capacity of the landscape matrix to facilitate species dispersals. Here, we assessed future range shifts for a suite of critically endangered plants in Madagascar. We quantified habitat connectivity using a least cost path model that captured the potential of species to disperse within fragmented landscapes. Next, we constructed three scenarios representing landscapes impacted by climate-only, climate and land-cover change, as well as habitat connectivity. We modelled species distributions using a hierarchical Bayesian framework and measured future range shifts using three spatial indices: net-change, range distance and elevation change. Our results show that the median range shift due to contractions increased by 25% under the climate-only scenario compared with the connectivity scenario. Habitat connectivity is predicted to limit range shifts due to contractions, while increasing shifts due to expansions for many of the endangered and critically endangered plants on Madagascar. However, at least one-third of critically endangered and 50% of endangered plants are expected to experience range contractions and upslope displacement under all scenarios, suggesting that even with habitat connectivity the range of some species may still contract. Despite that finding, our study suggests that including connectivity in range shift models is crucial for developing a relevant connectivity conservation plan, since future climate or climate and land-cover change models do not adequately represent species' potential to reach safe sites
Understanding the nature and mechanism of foot pain
Approximately one-quarter of the population are affected by foot pain at any given time. It is often disabling and can impair mood, behaviour, self-care ability and overall quality of life. Currently, the nature and mechanism underlying many types of foot pain is not clearly understood. Here we comprehensively review the literature on foot pain, with specific reference to its definition, prevalence, aetiology and predictors, classification, measurement and impact. We also discuss the complexities of foot pain as a sensory, emotional and psychosocial experience in the context of clinical practice, therapeutic trials and the placebo effect. A deeper understanding of foot pain is needed to identify causal pathways, classify diagnoses, quantify severity, evaluate long term implications and better target clinical intervention
Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model
We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society
Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model
We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO’s second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h95%0=3.47×10−25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering
Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers
Background: Dioscorea is a widely distributed and highly diversified genus in tropical regions where it is represented
by ten main clades, one of which diversified exclusively in Africa. In southern Africa it is characterised by a distinct
group of species with a pachycaul or “elephant’s foot” structure that is partially to fully exposed above the substrate.
In contrast to African representatives of the genus from other clades, occurring mainly in forest or woodland, the
pachycaul taxa and their southern African relatives occur in diverse habitats ranging from woodland to open
vegetation. Here we investigate patterns of diversification in the African clade, time of transition from forest to
more open habitat, and morphological traits associated with each habitat and evaluate if such transitions have
led to modification of reproductive organs and mode of dispersal.
Results: The Africa clade originated in the Oligocene and comprises four subclades. The Dioscorea buchananii
subclade (southeastern tropical Africa and South Africa) is sister to the East African subclade, which is respectively
sister to the recently evolved sister South African (e. g., Cape and Pachycaul) subclades. The Cape and Pachycaul
subclades diversified in the east of the Cape Peninsula in the mid Miocene, in an area with complex geomorphology
and climate, where the fynbos, thicket, succulent karoo and forest biomes meet.
Conclusions: Diversification out of forest is associated with major shifts in morphology of the perennial tuber
(specifically an increase in size and orientation which presumably led them to become pachycaul) and rotation of
stem (from twining to non-twining). The iconic elephant's foot morphology, observed in grasslands and thicket
biomes, where its corky bark may offer protection against fire and herbivory, evolved since mid Miocene. A shift
in pollination trait is observed within the forest, but entry into open habitat does not show association with
reproductive morphology, except in the seed wing, which has switched from winged all round the seed margin
to just at the base or at the apex of it, or has been even replaced by an elaiosome
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