Development and characterization of microsatellite markers for the French endemic Angelica heterocarpa (Apiaceae) and congeneric sympatric species

Objective Angelica heterocarpa (Apiaceae) is a wild endemic French species with special conservation interest in the European Union. It belongs to Angelica complex genus which is widespread throughout the north temperate zone, and is sympatric with other congeneric species. The objective of this work is to develop and characterize microsatellite markers as a new tool for understanding the ecology and evolution of Angelica species complex. Results We identified simple sequence repeat (SSR) regions in a microsatellite‐enriched library from A. heterocarpa and A. sylvestris. All 16 selected SSR regions were found to amplify in these species and were highly polymorphic. Marker transferability was validated in A. razulii and A. archangelica. These markers will help us to better understand the evolutionary dynamic between rare endemics and widespread sister species, and be useful for conservation of the endemic species. Moreover, they can provide new tools for studying the numerous traditional medicinal herbs of the Angelica genus.

Coloring inside the lines: genomic architecture and evolution of a widespread color pattern in frogs

Traits shared among distantly related lineages are indicators of common evolutionary constraints, at the ecological, physiological or molecular level. The vertebral stripe is a color pattern that is widespread across the anuran phylogeny. Despite its prevalence in the order, surprisingly little is known about the genetic basis and evolutionary dynamic of this color pattern. Here we combine histology, genome- and transcriptome-wide analyses with order-scale phylogenetic comparative analyses to investigate this common phenotype. We show that the vertebral stripe has evolved hundreds of times in the evolutionary history of anurans and is selected for in terrestrial habitats. Using the Ethiopian Ptychadena radiation as a model system, we demonstrate that variation at the ASIP gene is responsible for the different vertebral stripe phenotypes. Alleles associated to these phenotypes are younger than the split between closely related Ptychadena species, thus indicating that the vertebral stripe results from parallel evolution within the group. Our findings demonstrate that this widespread color pattern evolves rapidly and recurrently in terrestrial anurans, and therefore constitute an ideal system to study repeated evolution.

Building reusable phage and antibiotic treatments via exploitation of bacteria-phage coevolutionary dynamics.

People with chronic (long-lasting) infections face the problem that treatment options diminish in time as the pathogen evolves increasing resistance. To address this challenge, we exploit phage and bacterial co-evolution, producing dynamic selection pressures that can return the pathogen to a state of susceptibility to the initial (regulator-approved) therapy. We show that phage OMKO1 alone triggers Arms Race Dynamic (ARD) co-evolution with the pathogen Pseudomonas aeruginosa, leading to generalized phage resistance and crucially - failure at reuse. In contrast, co-administration of the phage with antibiotics triggers Fluctuating Selection Dynamics (FSD) co-evolution, allowing for effective reuse after 20 days of treatment. We pursue medical relevance in our experiments with the use of clinically important pathogens, antibiotics, phage, and a benchmarked synthetic sputum medium. Phenotypic and genomic characterization of evolved isolates demonstrates that efflux-targeting phage OMKO1 exerts continued selection for antibiotic susceptibility regardless of co-evolutionary dynamic or antibiotic co-treatment, opening the door for evolutionary robust phage therapy.

A wheat cysteine-rich receptor-like kinase confers broad-spectrum resistance against Septoria tritici blotch

The poverty of disease resistance gene reservoirs limits the breeding of crops for durable resistance against evolutionary dynamic pathogens. Zymoseptoria tritici which causes Septoria tritici blotch (STB), represents one of the most genetically diverse and devastating wheat pathogens worldwide. No fully virulent Z. tritici isolates against synthetic wheats carrying the major resistant gene Stb16q have been identified. Here, we use comparative genomics, mutagenesis and complementation to identify Stb16q, which confers broad-spectrum resistance against Z. tritici. The Stb16q gene encodes a plasma membrane cysteine-rich receptor-like kinase that was recently introduced into cultivated wheat and which considerably slows penetration and intercellular growth of the pathogen.

The Cardial–Epicardial Early Neolithic of Lower Rhône Valley (South-Eastern France): A Lithic Perspective

In the lower Rhône Valley, many sites are attributed to the Early Neolithic and dated between 5600 and 4800 cal. BC. According to their ceramic production, they are associated with two cultural facies: the Cardial and the Epicardial. The relation between these two entities is still under debate (chronological, cultural or functional distinctions?). However, little is known about the lithic production of the region since the chipped stone industries are rarely evoked in the socioeconomic and cultural understanding of these first agropastoral societies. The objective of this paper is to propose a regional synthesis regarding Early Neolithic lithic industries, based on typo-technological studies of several assemblages in the Rhône Valley: The Montclus rockshelter (layers 5 to 2), the Baume de Ronze rockshelter, Le Taï and the Aigle cave. These sites are considered to be the key sites for understanding the Cardial/Epicardial complex in this area, but their lithic assemblages have never been thoroughly studied. Special attention will be given to the factors of variability or, on the contrary, to the permanence in the “schema opératoire” and we will propose explanations related to geological, functional, chronological and cultural constraints. We will also focus on lithic blade production made from honey flint and the spacialisation of “chaine opératoire” which could highlight circulation of this raw material and specialised distribution network. Finally, this synthesis is based on a renewed corpus of radiocarbon dates in order to understand this evolutionary dynamic as finely as possible.