Search results for " Genetic"

Magnitude and direction of parasite‐induced phenotypic alterations: a meta‐analysis in acanthocephalans

2020

Several parasite species have the ability to modify their host's phenotype to their own advantage thereby increasing the probability of transmission from one host to another. This phenomenon of host manipulation is interpreted as the expression of a parasite extended phenotype. Manipulative parasites generally affect multiple phenotypic traits in their hosts, although both the extent and adaptive significance of such multidimensionality in host manipulation is still poorly documented. To review the multidimensionality and magnitude of host manipulation, and to understand the causes of variation in trait value alteration, we performed a phylogenetically corrected meta-analysis, focusing on a…

Dental microwear texture reflects dietary tendencies in extant Lepidosauria despite their limited use of oral food processing

2019

Lepidosauria show a large diversity in dietary adaptations, both among extant and extinct tetrapods. Unlike mammals, Lepidosauria do not engage in sophisticated mastication of their food and most species have continuous tooth replacement, further reducing the wear of individual teeth. However, dietary tendency estimation of extinct lepidosaurs usually rely on tooth shape and body size, which allows only for broad distinction between faunivores and herbivores. Microscopic wear features on teeth have long been successfully applied to reconstruct the diet of mammals and allow for subtle discrimination of feeding strategies and food abrasiveness. Here, we present, to our knowledge, the first de…

Technology generation to dissemination: lessons learned from the tef improvement project

2018

Indigenous crops also known as orphan crops are key contributors to food security, which is becoming increasingly vulnerable with the current trend of population growth and climate change. They have the major advantage that they fit well into the general socio-economic and ecological context of developing world agriculture. However, most indigenous crops did not benefit from the Green Revolution, which dramatically increased the yield of major crops such as wheat and rice. Here, we describe the Tef Improvement Project, which employs both conventional- and molecular-breeding techniques to improve tef—an orphan crop important to the food security in the Horn of Africa, a region of the world w…

Drastic Genome Reduction in an Herbivore's Pectinolytic Symbiont.

2017

Pectin, an integral component of the plant cell wall, is a recalcitrant substrate against enzymatic challenges by most animals. In characterizing the source of a leaf beetle’s (Cassida rubiginosa) pectin-degrading phenotype, we demonstrate its dependency on an extracellular bacterium housed in specialized organs connected to the foregut. Despite possessing the smallest genome (0.27 Mb) of any organism not subsisting within a host cell, the symbiont nonetheless retained a functional pectinolytic metabolism targeting the polysaccharide’s two most abundant classes: homogalacturonan and rhamnogalacturonan I. Comparative transcriptomics revealed pectinase expression to be enriched in the symbiot…

Linking species habitat and past palaeoclimatic events to evolution of the teleost innate immune system

2017

Host-intrinsic factors as well as environmental changes are known to be strong evolutionary drivers defining the genetic foundation of immunity. Using a novel set of teleost genomes and a time-calibrated phylogeny, we here investigate the family of Toll-like receptor ( TLR ) genes and address the underlying evolutionary processes shaping the diversity of the first-line defence. Our findings reveal remarkable flexibility within the evolutionary design of teleost innate immunity characterized by prominent TLR gene losses and expansions. In the order of Gadiformes, expansions correlate with the loss of major histocompatibility complex class II ( MHCII ) and diversifying selection analyses sup…

Stabilizing selection on microsatellite allele length at arginine vasopressin 1a receptor and oxytocin receptor loci

2017

The loci arginine vasopressin receptor 1a ( avpr1a ) and oxytocin receptor ( oxtr ) have evolutionarily conserved roles in vertebrate social and sexual behaviour. Allelic variation at a microsatellite locus in the 5′ regulatory region of these genes is associated with fitness in the bank vole Myodes glareolus . Given the low frequency of long and short alleles at these microsatellite loci in wild bank voles, we used breeding trials to determine whether selection acts against long and short alleles. Female bank voles with intermediate length avpr1a alleles had the highest probability of breeding, while male voles whose avpr1a alleles were very different in length had reduced probability of …

2021

Climate change is having a serious impact on many ecosystems. In the summer of 2018 and 2019, around two thirds of European beech trees were damaged or killed by extreme drought. It is critical to keep these beech woods healthy, as they are central to the survival of over 6,000 other species of animals and plants. The level of damage caused by the drought varied between forests. However, not all the trees in each forest responded in the same way, with severely damaged trees often sitting next to fully healthy ones. This suggests that the genetic make-up of each tree determines how well it can adapt to drought rather than its local environment. To investigate this further, Pfenninger et al. …

Effects of acclimation time and epigenetic mechanisms on growth of Neurospora in fluctuating environments

2017

AbstractReaction norms or tolerance curves have often been used to predict how organisms deal with fluctuating environments. A potential drawback is that reaction norms measured in different constant environments may not capture all aspects of organismal responses to fluctuating environments. We examined growth of the filamentous fungusNeurospora crassain fluctuating temperatures and tested if growth in fluctuating temperatures can be explained simply by growth in different constant temperatures or if more complex models are needed. In addition, as previous studies on fluctuating environments have revealed that past temperatures that organisms have experienced can affect their response to c…

Ecological genomics of adaptation to unpredictability in experimental rotifer populations

2019

AbstractElucidating the genetic basis of phenotypic variation in response to different environments is key to understanding how populations evolve. Facultatively sexual rotifers can develop adaptive responses to fluctuating environments. In a previous evolution experiment, diapause-related traits changed rapidly in response to two selective regimes (predictable vs unpredictable) in laboratory populations of the rotifer Brachionus plicatilis. Here, we investigate the genomic basis of adaptation to environmental unpredictability in these experimental populations. We identified and genotyped genome-wide polymorphisms in 169 clones from both selective regimes after seven cycles of selection usi…

Behavioural, ecological, and evolutionary aspects of diversity in frog colour patterns

2016

The role of colours and colour patterns in behavioural ecology has been extensively studied in a variety of contexts and taxa, while almost overlooked in many others. For decades anurans have been the focus of research on acoustic signalling due to the prominence of vocalisations in their communication. Much less attention has been paid to the enormous diversity of colours, colour patterns, and other types of putative visual signals exhibited by frogs. With the exception of some anecdotal observations and studies, the link between colour patterns and the behavioural and evolutionary ecology of anurans had not been addressed until approximately two decades ago. Since then, there has been eve…