Disruptive ecological selection on a mating cue Merrill, Richard M.; Wallbank, Richard W. R.; Bull, Vanessa ...
Proceedings - Royal Society. Biological sciences/Proceedings - Royal Society. Biological Sciences,
12/2012, Letnik:
279, Številka:
1749
Journal Article
Recenzirano
Odprti dostop
Adaptation to divergent ecological niches can result in speciation. Traits subject to disruptive selection that also contribute to non-random mating will facilitate speciation with gene flow. Such ...‘magic’ or ‘multiple-effect’ traits may be widespread and important for generating biodiversity, but strong empirical evidence is still lacking. Although there is evidence that putative ecological traits are indeed involved in assortative mating, evidence that these same traits are under divergent selection is considerably weaker. Heliconius butterfly wing patterns are subject to positive frequency-dependent selection by predators, owing to aposematism and Müllerian mimicry, and divergent colour patterns are used by closely related species to recognize potential mates. The amenability of colour patterns to experimental manipulation, independent of other traits, presents an excellent opportunity to test their role during speciation. We conducted field experiments with artificial butterflies, designed to match natural butterflies with respect to avian vision. These were complemented with enclosure trials with live birds and real butterflies. Our experiments showed that hybrid colour-pattern phenotypes are attacked more frequently than parental forms. For the first time, we demonstrate disruptive ecological selection on a trait that also acts as a mating cue.
The present study evaluated a Spanish-language version of an Anxiety Sensitivity Reduction Program for Smoking Cessation among a sample of daily adult smokers from Argentina (n=6; Mage=49.4, ...SD=15.43) in an open trial methodological design. To be eligible, each participant expressed a current desire to quit smoking and previous difficulties with anxiety/mood symptoms during past quit attempts (e.g., anxiety, stress, depression, irritability). Participants completed a baseline assessment and received eight 90-minute weekly group sessions. The study involved one doctoral-level and two graduate-level therapists. Follow-up visits were scheduled at 1, 2, 4, 8, and 12weeks post-quit day. Smoking status was confirmed biochemically and via self-report at quit day and each follow-up assessment. The treatment yielded positive results in terms of attendance, positive smoking cessation outcome (5 out of 6 were abstinent at 12-week follow-up), and significant reductions in anxiety sensitivity. The results suggest potential clinical utility among Spanish-speaking smokers for an anxiety-sensitivity smoking cessation program in regard to cessation outcome.
•Six participants competed a group treatment for smoking cessation•Anxiety sensitivity was specifically targeted in treatment•Five of six participants were abstinent at 12-week follow-up•There was a significant reduction in anxiety sensitivity from pre- to posttreatment
Advanced glycation end products (AGEs) are a diverse group of compounds that are formed as a result of the non-enzymatic reaction between a reducing sugar such as glucose and the free NH2 groups of ...an amino acid in a protein or other biomolecule. The chemical reaction, by which these products are generated, is known as the Maillard reaction and occurs as a part of the body’s normal metabolism. Such a reaction is enhanced during diabetes due to hyperglycemia, but it can also occur during the preparation, processing, and preservation of certain foods. Therefore, AGEs can also be obtained from the diet (d-AGE) and contribute to an increase of the total serum pool of these compounds. They have been implicated in a wide variety of pathological processes, mainly because of their ability to induce inflammatory responses and oxidative stress increase. They are extensively accumulated as a part of the normal aging, especially in tissues rich in long half-life proteins, which can compromise the physiology of these tissues. d-AGEs are abundant in diets rich in processed fats and sugars. This review is addressed to the current knowledge on these products and their impact on the immunomodulation of various mechanisms that may contribute to exacerbation of the diabetes pathophysiology.
Background
The novel 2019 SARS2-Coronavirus (COVID-19) has had a devastating physical health, mental health, and economic impact, causing millions of infections and hundreds of thousands of deaths. ...While COVID-19 has impacted the entire world, COVID-19 has disproportionately impacted low-income countries, particularly in South America, causing not only increased mortality but also increased associated mental health complaints. Anxiety sensitivity (AS), reflecting fear of anxiety-related physical sensations, may be particularly important to understand COVID-19 mental health effects among Latinx individuals in South America (Argentina). Past work suggests that Latinx individuals report greater somatization of mental health symptoms, and AS has been specifically linked to greater mental health symptoms. Yet, to date, no work has examined AS as a vulnerability factor for the negative mental health effects of COVID-19.
Method
Therefore, the current manuscript examined the association of AS with COVID-19 worry, functional impairment, anxiety, and symptom severity across two samples of adults in Argentina: a community sample (
n
= 105,
M
age
= 38.58,
SD
= 14.07, 69.5% female) and a clinical sample comprised of individuals with an anxiety disorder (
n =
99,
M
age
= 34.99,
SD
= 10.83, 66.7% female).
Results
Results from the current study provide support for AS as a potential vulnerability factor for COVID-19-related mental health problems across both samples, and these effects were evident over and above the variance accounted for by age, sex, pre-existing medical conditions, and COVID-19 exposure.
Conclusions
These data identify AS as a potential intervention target to reduce COVID-19 mental health burden among adults in Argentina.
Despite more than a century of biological research on the evolution and maintenance of mimetic signals, the relative frequencies of models and mimics necessary to establish and maintain Batesian ...mimicry in natural populations remain understudied. Here we investigate the frequency-dependent dynamics of imperfect Batesian mimicry, using predation experiments involving artificial butterfly models. We use two geographically distinct populations of Adelpha butterflies that vary in their relative frequencies of a putatively defended model (Adelpha iphiclus) and Batesian mimic (Adelpha serpa). We found that in Costa Rica, where both species share similar abundances, Batesian mimicry breaks down, and predators more readily attack artificial butterfly models of the presumed mimic, A. serpa. By contrast, in Ecuador, where A. iphiclus (model) is significantly more abundant than A. serpa (mimic), both species are equally protected from predation. Our results provide compelling experimental evidence that imperfect Batesian mimicry is frequency-dependent on the relative abundance of models and mimics in natural populations, and contribute to the growing body of evidence that complex dynamics, such as seasonality or the availability of alternative prey, influence the evolution of mimetic traits.
Significance
A defining goal in genetics is linking variation in DNA sequence to trait evolution between populations and, ultimately, species. Genome sequencing efficiently captures such variation ...but typically in millions of tiny fragments that omit haplotype or linkage information. We present “haplotagging,” a simple, rapid linked-read sequencing technique that allows high-throughput sequencing without sacrificing haplotype information. We validated this affordable approach for whole-genome haplotyping in large populations. We used haplotagging to investigate the rise of a novel hybrid morph in parallel hybrid zones of two comimetic
Heliconius
butterfly species in Ecuador. Our results reveal that strikingly parallel divergences in their genomes produced coordinated shifts in haplotype frequencies across the hybrid zone, giving rise to comimetic hybrid morphs in each species.
Genetic variation segregates as linked sets of variants or haplotypes. Haplotypes and linkage are central to genetics and underpin virtually all genetic and selection analysis. Yet, genomic data often omit haplotype information due to constraints in sequencing technologies. Here, we present “haplotagging,” a simple, low-cost linked-read sequencing technique that allows sequencing of hundreds of individuals while retaining linkage information. We apply haplotagging to construct megabase-size haplotypes for over 600 individual butterflies (
Heliconius erato
and
H. melpomene
), which form overlapping hybrid zones across an elevational gradient in Ecuador. Haplotagging identifies loci controlling distinctive high- and lowland wing color patterns. Divergent haplotypes are found at the same major loci in both species, while chromosome rearrangements show no parallelism. Remarkably, in both species, the geographic clines for the major wing-pattern loci are displaced by 18 km, leading to the rise of a novel hybrid morph in the center of the hybrid zone. We propose that shared warning signaling (Müllerian mimicry) may couple the cline shifts seen in both species and facilitate the parallel coemergence of a novel hybrid morph in both comimetic species. Our results show the power of efficient haplotyping methods when combined with large-scale sequencing data from natural populations.
Mimetic systems allow us to address the question of whether the same genes control similar phenotypes in different species. Although widespread parallels have been found for major effect loci, much ...less is known about genes that control quantitative trait variation. In this study, we identify and compare the loci that control subtle changes in the size and shape of forewing pattern elements in two Heliconius butterfly co‐mimics. We use quantitative trait locus (QTL) analysis with a multivariate phenotyping approach to map the variation in red pattern elements across the whole forewing surface of Heliconius erato and Heliconius melpomene. These results are compared with a QTL analysis of univariate trait changes, and show that our resolution for identifying small effect loci is somewhat improved with the multivariate approach, but also that different loci are detected with these different approaches. QTL likely corresponding to the known patterning gene optix were found in both species but otherwise, a remarkably low level of genetic parallelism was found. This lack of similarity indicates that the genetic basis of convergent traits may not be as predictable as assumed from studies that focus solely on Mendelian traits.
Heliconius erato and its co‐mimic H. melpomene show geographical variation in the size and shape of the red forewing band. We looked at whether subtle differences in pattern have the same level of genetic parallelism as major colour pattern elements in these mimetic species.
Flight was a key innovation in the adaptive radiation of insects. However, it is a complex trait influenced by a large number of interacting biotic and abiotic factors, making it difficult to unravel ...the evolutionary drivers. We investigate flight patterns in neotropical heliconiine butterflies, well known for mimicry of their aposematic wing color patterns. We quantify the flight patterns (wing beat frequency and wing angles) of 351 individuals representing 29 heliconiine and 9 ithomiine species belonging to ten color pattern mimicry groupings. For wing beat frequency and up wing angles, we show that heliconiine species group by color pattern mimicry affiliation. Convergence of down wing angles to mimicry groupings is less pronounced, indicating that distinct components of flight are under different selection pressures and constraints. The flight characteristics of the Tiger mimicry group are particularly divergent due to convergence with distantly related ithomiine species. Predator-driven selection for mimicry also explained variation in flight among subspecies, indicating that this convergence can occur over relatively short evolutionary timescales. Our results suggest that the flight convergence is driven by aposematic signaling rather than shared habitat between comimics. We demonstrate that behavioral mimicry can occur between lineages that have separated over evolutionary timescales ranging from <0.5 to 70 My.
Structural colours, produced by the reflection of light from ultrastructures, have evolved multiple times in butterflies. Unlike pigmentary colours and patterns, little is known about the genetic ...basis of these colours. Reflective structures on wing-scale ridges are responsible for iridescent structural colour in many butterflies, including the Müllerian mimics
and
Here, we quantify aspects of scale ultrastructure variation and colour in crosses between iridescent and non-iridescent subspecies of both of these species and perform quantitative trait locus (QTL) mapping. We show that iridescent structural colour has a complex genetic basis in both species, with offspring from crosses having a wide variation in blue colour (both hue and brightness) and scale structure measurements. We detect two different genomic regions in each species that explain modest amounts of this variation, with a sex-linked QTL in
but not
We also find differences between species in the relationships between structure and colour, overall suggesting that these species have followed different evolutionary trajectories in their evolution of structural colour. We then identify genes within the QTL intervals that are differentially expressed between subspecies and/or wing regions, revealing likely candidates for genes controlling structural colour formation. This article is part of the theme issue 'Genetic basis of adaptation and speciation: from loci to causative mutations'.
Understanding how organisms adapt to their local environment is central to evolution. With new whole‐genome sequencing technologies and the explosion of data, deciphering the genomic basis of complex ...traits that are ecologically relevant is becoming increasingly feasible. Here, we studied the genomic basis of wing shape in two Neotropical butterflies that inhabit large geographical ranges. Heliconius butterflies at high elevations have been shown to generally have rounder wings than those in the lowlands. We reared over 1,100 butterflies from 71 broods of H. erato and H. melpomene in common‐garden conditions and showed that wing aspect ratio, that is, elongatedness, is highly heritable in both species and that elevation‐associated wing aspect ratio differences are maintained. Genome‐wide associations with a published data set of 666 whole genomes from across a hybrid zone, uncovered a highly polygenic basis to wing aspect ratio variation in the wild. We identified several genes that have roles in wing morphogenesis or wing aspect ratio variation in Drosophila flies, making them promising candidates for future studies. There was little evidence for molecular parallelism in the two species, with only one shared candidate gene, nor for a role of the four known colour pattern loci, except for optix in H. erato. Thus, we present the first insights into the heritability and genomic basis of within‐species wing aspect ratio in two Heliconius species, adding to a growing body of evidence that polygenic adaptation may underlie many ecologically relevant traits.
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