Researchers have long suggested that animals with greater behavioural flexibility will be more likely to survive in face of environmental changes. However, it is unknown how this varies across ...species. Nest building is a behaviour directly related to the reproduction and survival of species by conferring protection from external environmental conditions. The study of nests offers a window into the behaviour of birds, and variation in nest morphology is necessarily linked to variation in building behaviours. We test whether variation in nest morphology is phylogenetically conserved by using data on nest morphology from 55 passerine species (>700 specimens) and measuring intraspecific variability in nest structure. We found that species mean and within-species variation in nest morphology are phylogenetically conserved, and that species with domed nests presented higher levels of nest morphology variation than cup nest species. We also revealed that the capacity of species to present innovative behaviours is not linked with how they vary nest morphology. Moreover, we revealed that nests from species with larger variation in clutch size and that are built by single parents are more variable. Our results help in the understanding of how behaviour and extended phenotypes evolve, and highlight the importance of exploring the phylogenetic history of behavioural flexibility when trying to predict the capacity of species to respond to novel challenges. This article is part of the theme issue 'The evolutionary ecology of nests: a cross-taxon approach'.
Aim
Management of osteoarthritis (OA) is basically symptomatic. Recently, stem cells (SC) have been used in the search for an optimum treatment. We decided to conduct a controlled clinical trial to ...determine if a single intra‐articular injection of in vivo stimulated bone marrow SC could lead to an improvement in pain management and quality of life in patients with knee OA.
Method
This was a prospective, open‐label, phase I/II clinical trial to assess the safety and efficacy of a single intra‐articular injection of autologous stimulated bone marrow stem cells (BM‐SC) in patients with knee OA. Individuals of both genders older than 30 years with confirmed diagnosis of OA who signed informed consent were included in two groups: SC group received in vivo BM stimulation with subcutaneous administration of granulocyte colony stimulating factor (G‐CSF). SC were obtained by BM aspiration and administered in a single intra‐articular injection. The control group received exclusively oral acetaminophen. Visual analogue scale and Western Ontario and McMaster Universities Osteoarthritis Index scores were performed at 1 week, 1 month and 6 months in both groups. This trial was registered in ClinialTrials.gov NCT01485198.
Results
A total of 61 patients were included. Socio‐demographic characteristics, OA grades and initial scores were similar in both groups. The BM‐SC group showed significant improvement in knee pain and quality of life during the 6‐month follow‐up.
Conclusion
The study demonstrates feasibility and supports efficacy of a completely ambulatory procedure in treatment of knee OA.
The mitochondrial calcium uniporter complex is essential for calcium (Ca2+) uptake into mitochondria of all mammalian tissues, where it regulates bioenergetics, cell death, and Ca2+ signal ...transduction. Despite its involvement in several human diseases, we currently lack pharmacological agents for targeting uniporter activity. Here we introduce a high-throughput assay that selects for human MCU-specific small-molecule modulators in primary drug screens. Using isolated yeast mitochondria, reconstituted with human MCU, its essential regulator EMRE, and aequorin, and exploiting a D-lactate- and mannitol/sucrose-based bioenergetic shunt that greatly minimizes false-positive hits, we identify mitoxantrone out of more than 600 clinically approved drugs as a direct selective inhibitor of human MCU. We validate mitoxantrone in orthogonal mammalian cell-based assays, demonstrating that our screening approach is an effective and robust tool for MCU-specific drug discovery and, more generally, for the identification of compounds that target mitochondrial functions.
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•Targeting human MCU in yeast mitochondria is an effective drug discovery strategy•A yeast-specific bioenergetic shunt minimizes detection of false-positive hits•An orthogonal, interspecies drug screening can identify specific MCU modulators•Mitoxantrone is a selective and direct inhibitor of MCU
Arduino et al. develop a high-throughput drug discovery strategy to identify chemical modulators of the mitochondrial calcium uniporter. They find that mitoxantrone is a selective and direct inhibitor of the MCU channel.
Nests are essential constructions that determine fitness, yet their structure can vary substantially across bird species. While there is evidence supporting a link between nest architecture and the ...habitat a species occupies, we still ignore what ecological and evolutionary processes are linked to different nest types. Using information on 3175 species of songbirds, we show that—after controlling for latitude and body size—species that build domed nests (i.e. nests with a roof) have smaller ranges, are less likely to colonise urban environments and have potentially higher extinction rates compared to species with open and cavity nests. Domed nests could be a costly specialisation, and we show that these nests take more time to be built, which could restrict breeding opportunities. These diverse strands of evidence suggest that the transition from domed to open nests in passerines could represent an important evolutionary innovation behind the success of the largest bird radiation.
Nests are fundamental structures in the lives of birds, but we know little about their evolution. We collated information on nest architecture for more than 3000 species, and found that building nests without a roof (open nests) is associated with having larger geographic ranges and living in cities. These nests also take less days to construct compared to domed nests. We suggest that building open instead of domed nests could have played an important role in the ecological success of modern birds.
Predator-prey interactions have been suggested as drivers of diversity in different lineages, and the presence of anti-predator defences in some clades is linked to higher rates of diversification. ...Warning signals are some of the most widespread defences in the animal world, and there is evidence of higher diversification rates in aposematic lineages. The mechanisms behind such species richness, however, are still unclear. Here, we test whether lineages that use aposematism as anti-predator defence exhibit higher levels of genetic differentiation between populations, leading to increased opportunities for divergence. We collated from the literature more than 3000 pairwise genetic differentiation values across more than 700 populations from over 60 amphibian species. We find evidence that over short geographical distances, populations of species of aposematic lineages exhibit greater genetic divergence relative to species that are not aposematic. Our results support a scenario where the use of warning signals could restrict gene flow, and suggest that anti-predator defences could impact divergence between populations and potentially have effects at a macro-evolutionary scale.
Animal synchrony is found in phylogenetically distant animal groups, indicating behavioral adaptations to different selective pressures and in different signaling modalities. A notable example of ...synchronous display is found in fiddler crabs in that males wave their single enlarged claw during courtship. They present species-specific signals, which are composed of distinctive movement signatures. Given that synchronous waving has been reported for several fiddler crab species, the display pattern could influence the ability of a given species to sufficiently adjust wave timing to allow for synchrony. In this study, we quantified the wave displays of fiddler crabs to predict their synchronous behavior. We combined this information with the group’s phylogenetic relationships to trace the evolution of display synchrony in an animal taxon. We found no phylogenetic signal in interspecific variation in predicted wave synchrony, which mirrors the general nonphylogenetic pattern of synchrony across animal taxa. Interestingly, our analyses show that the phenomenon of synchronization stems from the peculiarities of display pattern, mating systems, and the complexity of microhabitats. This is the first study to combine mathematical simulations and phylogenetic comparative methods to reveal how ecological factors and the mechanics of animal signals affect the evolution of the synchronous phenomena.
Avian nests are critical for successful reproduction in birds. Nest microclimate can affect egg development, chick growth and fledgling success, suggesting that nest building behavior should be under ...strong selective pressure to nesting conditions. Given that the internal microclimate of the nest is critical for avian fitness, it is expected that nest morphology is shaped by the local environment. Here we review the relationship between nest morphology and climate across species’ distributions. We collate growing evidence that supports a link between environmental conditions and particular nest traits, within species and across species. We discuss the degree to which phenotypic plasticity in nesting behavior can contribute to observed variation in nest traits, the role of phylogenetic history in determining nest morphology, and which nest traits are likely to be influenced by climatic conditions. Finally, we identify gaps in our understanding of the evolution of nest morphology and suggest topics for future research. Overall, we argue that nests are part of the extended phenotype of a bird, they play a crucial role in their reproductive success, and may be an important factor in determining which species will be able to persist in the face of ongoing climate change.
Synchrony can be defined as the precise coordination between independent individuals, and this behaviour is more enigmatic when it is imperfect. The traditional theoretical explanation for imperfect ...synchronous courtship is that it arises as a by-product of the competition between males to broadcast leading signals to attract female attention. This competition is considered an evolutionary stable strategy maintained through sexual selection. However, previous studies have revealed that leading signals are not honest indicators of male quality. We studied imperfect courtship synchrony in fiddler crabs to mainly test whether (i) signal leadership and rate are defined by male quality and (ii) signal leadership generates synchrony. Fiddler crab males wave their enlarged claws during courtship, and females prefer leading males-displaying ahead of their neighbour(s). We filmed groups of waving males in the field to detect how often individuals were leaders and if they engaged in synchrony. Overall, we found that courtship effort is not directly related to male size, a general proxy for quality. Contrary to the long-standing assumption, we also revealed that leadership is not directly related to group synchrony, but faster wave rate correlates with both leadership and synchrony. This article is part of the theme issue 'Synchrony and rhythm interaction: from the brain to behavioural ecology'.
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