Search results for "GRI"
showing 10 items of 10209 documents
Enemy recognition is linked to soldier size in a polymorphic stingless bee
2017
Many ant and termite colonies are defended by soldiers with powerful mandibles or chemical weaponry. Recently, it was reported that several stingless bee species also have soldiers for colony defence. These soldiers are larger than foragers, but otherwise lack obvious morphological adaptations for defence. Thus, how these soldiers improve colony fitness is not well understood. Robbing is common in stingless bees and we hypothesized that increased body size improves the ability to recognize intruders based on chemosensory cues. We studied the Neotropical species Tetragonisca angustula and found that large soldiers were better than small soldiers at recognizing potential intruders. Larger so…
Modelling nonlinear dynamics of Crassulacean acid metabolism productivity and water use for global predictions
2021
Crassulacean acid metabolism (CAM) crops are important agricultural commodities in water-limited environments across the globe, yet modeling of CAM productivity lacks the sophistication of widely used C3 and C4 crop models, in part due to the complex responses of the CAM cycle to environmental conditions. This work builds on recent advances in CAM modeling to provide a framework for estimating CAM biomass yield and water use efficiency from basic principles. These advances, which integrate the CAM circadian rhythm with established models of carbon fixation, stomatal conductance, and the soil-plant-atmosphere continuum, are coupled to models of light attenuation, plant respiration, and bioma…
Strength of sexual and postmating prezygotic barriers varies between sympatric populations with different histories and species abundances.
2019
The impact of different reproductive barriers on species or population isolation may vary in different stages of speciation depending on evolutionary forces acting within species and through species' interactions. Genetic incompatibilities between interacting species are expected to reinforce prezygotic barriers in sympatric populations and lead to cascade reinforcement between conspecific populations living within and outside the areas of sympatry. We tested these predictions and studied whether and how the strength and target of reinforcement between Drosophila montana and Drosophila flavomontana vary between sympatric populations with different histories and species abundances. All barri…
Morphometrics and Cladistics: Measuring Phylogeny in the Sea Urchin Echinocardium
1996
A phylogenetic approach to the study of evolutionary patterns is based on taxic homologies (synapomorphies). In contrast, the recognition of evolutionary processes (namely heterochronies) involves analysis of the entire morphology. Recent developments in geometric morphometry permit analysis of morphological similarities grounded in operational homologies. Such morphometric techniques are explored (1) at the level of evolutionary processes, and (2) as a complement in exploration of phylogenetic relationships. To examplify this, we perform a two-part study of the ontogeny and phylogeny of the spatangoid sea urchin Echinocardium. First, a phylogenetic analysis of ten Recent species in the gen…
Variable crab camouflage patterns defeat search image formation.
2021
Understanding what maintains the broad spectrum of variation in animal phenotypes and how this influences survival is a key question in biology. Frequency dependent selection – where predators temporarily focus on one morph at the expense of others by forming a “search image” – can help explain this phenomenon. However, past work has never tested real prey colour patterns, and rarely considered the role of different types of camouflage. Using a novel citizen science computer experiment that presented crab “prey” to humans against natural backgrounds in specific sequences, we were able to test a range of key hypotheses concerning the interactions between predator learning, camouflage and mor…
Polyamine Oxidase 5 loss-of-function mutations in Arabidopsis thaliana trigger metabolic and transcriptional reprogramming and promote salt stress to…
2017
The family of polyamine oxidases (PAO) in Arabidopsis (AtPAO1-5) mediates polyamine (PA) back-conversion, which reverses the PA biosynthetic pathway from spermine, and its structural isomer thermospermine (tSpm), into spermidine and then putrescine. Here, we have studied the involvement of PA back-conversion in Arabidopsis salinity tolerance. AtPAO5 is the Arabidopsis PAO gene member most transcriptionally induced by salt stress. Two independent loss-of-function mutants (atpao5-2 and atpao5-3) were found to exhibit constitutively higher tSpm levels, with associated increased salt tolerance. Using global transcriptional and metabolomic analyses, the underlying mechanisms were studied. Stimul…
Symptom severity, infection progression and plant responses in solanum plants caused by three pospiviroids vary with the inoculation procedure
2021
This article belongs to the Section Molecular Plant Sciences.
Take a Trip Through the Plant and Fungal Transportome of Mycorrhiza
2016
International audience; Soil nutrient acquisition and exchanges through symbiotic plant–fungus interactions in the rhizosphere are key features for the current agricultural and environmental challenges. Improved crop yield and plant mineral nutrition through a fungal symbiont has been widely described. In return, the host plant supplies carbon substrates to its fungal partner. We review here recent progress on molecular players of membrane transport involved in nutritional exchanges between mycorrhizal plants and fungi. We cover the transportome, from the transport proteins involved in sugar fluxes from plants towards fungi, to the uptake from the soil and exchange of nitrogen, phosphate, p…
Learned parasite avoidance is driven by host personality and resistance to infection in a fish-trematode interaction
2016
Cognitive abilities related to the assessment of risk improve survival. While earlier studies have examined the ability of animals to learn to avoid predators, learned parasite avoidance has received little interest. In a series of behavioural trials with the trematode parasite Diplostomum pseudospathaceum , we asked whether sea trout ( Salmo trutta trutta ) hosts show associative learning in the context of parasitism and if so, whether learning capacity is related to the likelihood of infection mediated through host personality and resistance. We show that animals are capable of learning to avoid visual cues associated with the presence of parasites. However, avoidance behaviour ceased af…