Lippens C.,Montpellier SupAgro
Heredity | Year: 2017
Knowledge of the genetic make-up and demographic history of invasive populations is critical to understand invasion mechanisms. Commensal rodents are ideal models to study whether complex invasion histories are typical of introductions involving human activities. The house mouse Mus musculus domesticus is a major invasive synanthropic rodent originating from South-West Asia. It has been largely studied in Europe and on several remote islands, but the genetic structure and invasion history of this taxon have been little investigated in several continental areas, including West Africa. In this study, we focussed on invasive populations of M. m. domesticus in Senegal. In this focal area for European settlers, the distribution area and invasion spread of the house mouse is documented by decades of data on commensal rodent communities. Genetic variation at one mitochondrial locus and 16 nuclear microsatellite markers was analysed from individuals sampled in 36 sites distributed across the country. A combination of phylogeographic and population genetics methods showed that there was a single introduction event on the northern coast of Senegal, from an exogenous (probably West European) source, followed by a secondary introduction from northern Senegal into a coastal site further south. The geographic locations of these introduction sites were consistent with the colonial history of Senegal. Overall, the marked microsatellite genetic structure observed in Senegal, even between sites located close together, revealed a complex interplay of different demographic processes occurring during house mouse spatial expansion, including sequential founder effects and stratified dispersal due to human transport along major roads.Heredity advance online publication, 29 March 2017; doi:10.1038/hdy.2017.18. © 2017 The Genetics Society Macmillan Publishers Limited, part of Springer Nature.
Montpellier SupAgro, French National Institute for Agricultural Research and Danstar Ferment AG | Date: 2016-11-02
The present disclosure concerns a composition comprising yeast cells and at least one polyphenols having a molecular weight above 620 Da, the polyphenols are adsorbed and retained in the cytoplasm of the yeast cell. The present disclosure also concerns using the composition in cosmetic, dermatological, nutritional and / or pharmaceutical fields, as well as in winemaking to protect the wine against oxidation, therefore preserving the wine quality, color and aromas, and as an alternative to ageing of wine on lees.
French National Institute for Agricultural Research and Montpellier SupAgro | Date: 2013-01-24
The present invention relates to the identification of alleles of the MET2 and SKP2 genes having the effect of reducing the production of sulphites, of hydrogen sulphide and of acetaldehyde by Saccharomyces, and to the use of these alleles in methods for controlling the production of these compounds during alcoholic fermentation.
French National Center for Scientific Research, Montpellier University and Montpellier SupAgro | Date: 2013-06-06
The present invention concerns a process for preparing a compound of formula (I) by reaction between a compound of formula (II) and a compound of formula (III) in the presence of a copper-containing catalyst, a ligand and base. The invention also concerns the implementing of this process for the preparation of building blocks to prepare molecules of interest in particular in the pharmaceutical, agro-chemical fields, etc.
Estoup A.,Montpellier SupAgro |
Guillemaud T.,University of Nice Sophia Antipolis
Molecular Ecology | Year: 2010
Detailed knowledge about the geographical pathways followed by propagules from their source to the invading populations - referred to here as routes of invasion - provides information about the history of the invasion process and the origin and genetic composition of the invading populations. The reconstruction of invasion routes is required for defining and testing different hypotheses concerning the environmental and evolutionary factors responsible for biological invasions. In practical terms, it facilitates the design of strategies for controlling or preventing invasions. Most of our knowledge about the introduction routes of invasive species is derived from historical and observational data, which are often sparse, incomplete and, sometimes, misleading. In this context, population genetics has proved a useful approach for reconstructing routes of introduction, highlighting the complexity and the often counterintuitive nature of the true story. This approach has proved particularly useful since the recent development of new model-based methods, such as approximate Bayesian computation, making it possible to make quantitative inferences in the complex evolutionary scenarios typically encountered in invasive species. In this review, we summarize some of the fundamental aspects of routes of invasion, explain why the reconstruction of these routes is useful for addressing both practical and theoretical questions, and comment on the various reconstruction methods available. Finally, we consider the main insights obtained to date from studies of invasion routes. © 2010 Blackwell Publishing Ltd.
Rossi J.-P.,Montpellier SupAgro
Diversity | Year: 2011
The paper describes rich, a new R package to perform species richness estimation and comparison. Species richness is the simplest surrogate for the more complex concept of species biodiversity. It is relatively easy to assess although estimations strongly depend on sampling intensity with the consequence that richness estimations should be standardized to perform valid comparisons. The R package rich allows such corrections as well as the computation of various statistics and implements different randomization tests to compare cumulative and average species richness of two communities. These tests are useful for ranking sites or communities which is a classical goal in restoration ecology and conservation biology. © 2011 by the authors.
Chapuis E.,Montpellier SupAgro
Proceedings. Biological sciences / The Royal Society | Year: 2012
Our current understanding on how pathogens evolve relies on the hypothesis that pathogens' transmission is traded off against host exploitation. In this study, we surveyed the possibility that trade-offs determine the evolution of the bacterial insect pathogen, Xenorhabdus nematophila. This bacterium rapidly kills the hosts it infects and is transmitted from host cadavers to new insects by a nematode vector, Steinernema carpocapsae. In order to detect trade-offs in this biological system, we produced 20 bacterial lineages using an experimental evolution protocol. These lineages differ, among other things, in their virulence towards the insect host. We found that nematode parasitic success increases with bacteria virulence, but their survival during dispersal decreases with the number of bacteria they carry. Other bacterial traits, such as production of the haemolytic protein XaxAB, have a strong impact on nematode reproduction. We then combined the result of our measurements with an estimate of bacteria fitness, which was divided into a parasitic component and a dispersal component. Contrary to what was expected in the trade-off hypothesis, we found no significant negative correlation between the two components of bacteria fitness. Still, we found that bacteria fitness is maximized when nematodes carry an intermediate number of cells. Our results therefore demonstrate the existence of a trade-off in X. nematophila, which is caused, in part, by the reduction in survival this bacterium causes to its nematode vectors.
Tixier M.-S.,Montpellier SupAgro
Cladistics | Year: 2012
Statistical methods for delimiting species with morphological data remain woefully understudied. The present study presents statistical approaches to study the intraspecific variations of continuous characters used in species diagnosis. For this, the data set comprised 14 species of the mite family Phytoseiidae (Acari: Mesostigmata) and 23 continuous characters (seta lengths). The statistical approaches aim to determine (i) how intraspecific variations differ depending on the characters and species considered, and (ii) how to choose the number of specimens to be considered for characterizing intraspecific boundaries. The means of the related confident limits at 95% (rCL 95) of the 14 species and the 23 setae are around 20%, suggesting that 95% of the specimens of a same species are included in the interval μ±0.2μ. No relationship was found between seta variations and the number of specimens considered for each species, nor for seta variations and their position on the mite body. However, a correlation between seta lengths and rCL 95 means was observed. An abacus was proposed to determine the coefficient that must be applied to mean seta length to calculate the lower and upper limits of the interval that will include 95% of the specimens of a same species. The higher the precision around the mean, the higher the number of specimens considered. Furthermore, this number varies considerably depending on the characters and species considered for high precisions. However, for a priori error around the mean of 15%, the number of specimens needed to characterize the intraspecific variation is quite homogeneous and ten specimens would be required. I discuss the utility of such results to resolve some persistent problems in the alpha-taxonomy of the family Phytoseiidae but also of other taxa. © The Willi Hennig Society 2012.
Gautier M.,Montpellier SupAgro |
Vitalis R.,Montpellier SupAgro
Bioinformatics | Year: 2012
Summary: With the development of next-generation sequencing and genotyping approaches, large single nucleotide polymorphism haplotype datasets are becoming available in a growing number of both model and non-model species. Identifying genomic regions with unexpectedly high local haplotype homozygosity relatively to neutral expectation represents a powerful strategy to ascertain candidate genes responding to natural or artificial selection. To facilitate genome-wide scans of selection based on the analysis of long-range haplotypes, we developed the R package rehh. It provides a versatile tool to detect the footprints of recent or ongoing selection with several graphical functions that help visual interpretation of the results. © The Author 2012. Published by Oxford University Press. All rights reserved.
Granier C.,Montpellier SupAgro |
Vile D.,Montpellier SupAgro
Current Opinion in Plant Biology | Year: 2014
Plant phenotyping technology has become more advanced with the capacity to measure many morphological and physiological traits on a given individual. With increasing automation, getting access to various traits on a high number of genotypes over time raises the need to develop systems for data storage and analyses, all congregating into plant phenotyping pipelines. In this review, we highlight several studies that illustrate the latest advances in plant multi-trait phenotyping and discuss future needs to ensure the best use of all these quantitative data. We assert that the next challenge is to disentangle how plant traits are embedded in networks of dependencies (and independencies) by modelling the relationships between them and how these are affected by genetics and environment. © 2014 Elsevier Ltd.