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Evolutionary history of two cryptic species of northern African jerboas
2020
Abstract Background: Climatic variation and geologic change both play significant roles in shaping species distributions, thus affecting their evolutionary history. In Sahara-Sahel, climatic oscillations shifted the desert extent during the Pliocene-Pleistocene interval, triggering the diversification of several species. Here, we investigated how these biogeographical and ecological events have shaped patterns of genetic diversity and divergence in African Jerboas, desert specialist rodents. We focused on two sister and cryptic species, Jaculus jaculus and J. hirtipes, where we (1) evaluated their genetic differentiation, (2) reconstructed their evolutionary and demographic history; (3) tes…
Arabidopsis RCD1 coordinates chloroplast and mitochondrial functions through interaction with ANAC transcription factors
2019
Reactive oxygen species (ROS)-dependent signaling pathways from chloroplasts and mitochondria merge at the nuclear protein RADICAL-INDUCED CELL DEATH1 (RCD1). RCD1 interacts in vivo and suppresses the activity of the transcription factors ANAC013 and ANAC017, which mediate a ROS-related retrograde signal originating from mitochondrial complex III. Inactivation of RCD1 leads to increased expression of mitochondrial dysfunction stimulon (MDS) genes regulated by ANAC013 and ANAC017. Accumulating MDS gene products, including alternative oxidases (AOXs), affect redox status of the chloroplasts, leading to changes in chloroplast ROS processing and increased protection of photosynthetic apparatus.…
New Insights on the Evolutionary History of Aphids and Their Primary Endosymbiont Buchnera aphidicola
2011
Since the establishment of the symbiosis between the ancestor of modern aphids and their primary endosymbiont,Buchnera aphidicola, insects and bacteria have coevolved. Due to this parallel evolution, the analysis of bacterial genomic features constitutes a useful tool to understand their evolutionary history. Here we report, based on data fromB. aphidicola, the molecular evolutionary analysis, the phylogenetic relationships among lineages and a comparison of sequence evolutionary rates of symbionts of four aphid species from three subfamilies. Our results support previous hypotheses of divergence ofB. aphidicolaand their host lineages during the early Cretaceous and indicate a closer relati…
Migratory passage structures at hydropower plants as potential physiological and behavioural selective agents
2019
Anthropogenic activities affect fish populations worldwide. River dams have profound impacts on ecosystems by changing habitats and hindering migration. In an effort to counteract such effects, a range of mitigation measures have been installed at hydroelectric power plants. However, not all individuals in a population use these measures, potentially creating strong selection processes at hydroelectric power plants. This may be especially true during migration; fish can get heavily delayed or pass through a hydropower turbine, thus facing increased mortality compared with those using a safe bypass route. In this study, we quantify migration route choices of descending wild passive integrate…
Biomechanics and functional morphology of a climbing monocot.
2015
Climbing monocots can develop into large bodied plants despite being confined by primary growth. In our study on Flagellaria indica we measured surprisingly high stem biomechanical properties (in bending and torsion) and we show that the lack of secondary growth is overcome by a combination of tissue maturation processes and attachment mode. This leads to higher densities of mechanically relevant tissues in the periphery of the stem and to the transition from self-supporting to climbing growth. The development of specialised attachment structures has probably underpinned the evolution of numerous other large bodied climbing monocot taxa.
Evolution of the Globin Gene Family in Deuterostomes: Lineage-Specific Patterns of Diversification and Attrition
2012
In the Metazoa, globin proteins display an underlying unity in tertiary structure that belies an extraordinary diversity in primary structures, biochemical properties, and physiological functions. Phylogenetic reconstructions can reveal which of these functions represent novel, lineage-specific innovations, and which represent ancestral functions that are shared with homologous globin proteins in other eukaryotes and even prokaryotes. To date, our understanding of globin diversity in deuterostomes has been hindered by a dearth of genomic sequence data from the Ambulacraria (echinoderms + hemichordates), the sister group of chordates, and the phylum Xenacoelomorpha, which includes xenoturbel…
Acceptance and knowledge of evolutionary theory among third-year university students in Spain
2020
The theory of evolution is one of the greatest scientific achievements in the intellectual history of humankind, yet it is still contentious within certain social groups. Despite being as robust and evidence-based as any other notable scientific theory, some people show a strong reluctance to accept it. In this study, we used the Measure of Acceptance of the Theory of Evolution (MATE) and Knowledge of Evolution Exam (KEE) questionnaires with university students from four academic degree programs (Chemistry, English, History, and Biology) of ten universities from Spain to measure, respectively, acceptance and knowledge of evolutionary theory among third-year undergraduate students (nMATE = 9…
Effects of predation pressure and resource use on morphological divergence in omnivorous prey fish
2013
Background. Body shape is one of the most variable traits of organisms and responds to a broad array of local selective forces. In freshwater fish, divergent body shapes within single species have been repeatedly observed along the littoral-pelagic axes of lakes, where the structural complexity of near shore habitats provides a more diverse set of resources compared to the open-water zones. It remains poorly understood whether similar resource-driven polymorphism occurs among lakes that vary in structural complexity and predation pressure, and whether this variation is heritable. Here, we analyzed body shape in four populations of omnivorous roach (Rutilus rutilus) inhabiting shallow lakes.…
Functional reconstitution of a proton-translocating system responsive to fusicoccin
1988
Crude fusicoccin binding proteins and a partially purified plasma membrane H+-transporting ATPase (EC 3.6.1.34), both solubilized from maize tissues, were simultaneously inserted into liposomes by the freeze-thaw method. ATP-driven intravesicular acidification in the proteoliposomes, measured by the fluorescence quenching of the dye 9-amino-6-chloro-2-methoxyacridine, markedly increased upon addition of fusicoccin to the reconstituted system. This effect could not be observed when binding sites and ATPase preparations were separately reconstituted into the proteoliposomes, thus demonstrating that fusicoccin binding to its receptor is a prerequisite for ATPase stimulation.
Variability and cryptic heteromorphism of Ambrosia artemisiifolia seeds: What consequences for its invasion in France
2007
International audience; Background and Aims:Ambrosia artemisiifolia is a ruderal weed introduced from North America to Europe. It produces large amount of achenes which are highly heterogeneous in size. Due to the preponderant role of propagules in invasive plant processes, the achene mass variability related to germination, dispersal strategy and life history traits of offspring were investigated within this species. Methods:The variability in achene mass was quantified among six populations sampled in different habitats. The effects of achene mass variation on germination were studied. The percentages of floating and non-floating achenes were evaluated in the studied populations. The cons…