Search results for "polymorphisme"

A genomic map of climate adaptation in Mediterranean cattle breeds

2019

International audience; Domestic species such as cattle (Bos taurus taurus and B. t. indicus) represent attractive biological models to characterize the genetic basis of short term evolutionary response to climate pressure induced by their post-domestication history. Here, using newly generated dense SNP genotyping data, we assessed the structuring of genetic diversity of 21 autochtonous cattle breeds from the whole Mediterranean basin and performed genome-wide association analyses with covariables discriminating the different Mediterranean climate sub-types. This provided insights into both the demographic and adaptive histories of Mediterranean cattle. In particular, a detailed functional…

Evolution of sexually dimorphic pheromone profiles coincides with increased number of male‐specific chemosensory organs in Drosophila prolongata

2019

Abstract Binary communication systems that involve sex‐specific signaling and sex‐specific signal perception play a key role in sexual selection and in the evolution of sexually dimorphic traits. The driving forces and genetic changes underlying such traits can be investigated in systems where sex‐specific signaling and perception have emerged recently and show evidence of potential coevolution. A promising model is found in Drosophila prolongata, which exhibits a species‐specific increase in the number of male chemosensory bristles. We show that this transition coincides with recent evolutionary changes in cuticular hydrocarbon (CHC) profiles. Long‐chain CHCs that are sexually monomorphic …

Experimental Introgression To Evaluate the Impact of Sex Specific Traits on Drosophila melanogaster Incipient Speciation

2019

AbstractSex specific traits are involved in speciation but it is difficult to determine whether their variation initiates or reinforces sexual isolation. In some insects, speciation depends of the rapid change of expression in desaturase genes coding for sex pheromones. Two closely related desaturase genes are involved in Drosophila melanogaster pheromonal communication: desat1 affects both the production and the reception of sex pheromones while desat2 is involved in their production in flies of Zimbabwe populations. There is a strong asymmetric sexual isolation between Zimbabwe populations and all other “Cosmopolitan” populations: Zimbabwe females rarely copulate with Cosmopolitan males w…

Genotypic characterization of Bradyrhizobium strains nodulating small Senegalese legumes by 16S-23S rRNA intergenic gene spacers and amplified fragme…

2000

ABSTRACT We examined the genotypic diversity of 64 Bradyrhizobium strains isolated from nodules from 27 native leguminous plant species in Senegal (West Africa) belonging to the genera Abrus , Alysicarpus , Bryaspis , Chamaecrista , Cassia , Crotalaria , Desmodium , Eriosema , Indigofera , Moghania , Rhynchosia , Sesbania , Tephrosia , and Zornia , which play an ecological role and have agronomic potential in arid regions. The strains were characterized by intergenic spacer (between 16S and 23S rRNA genes) PCR and restriction fragment length polymorphism (IGS PCR-RFLP) and amplified fragment length polymorphism (AFLP) fingerprinting analyses. Fifty-three reference strains of the different B…

Genetic and aromatic diversity of the Burgundy truffle

2013

Truffles are ectomycorrhizal Ascomycota fungi belonging to the Tuberaceae family and more specifically to the Tuber genus. More than thirty Tuber species are currently described in Europe. In this thesis, we specifically focused on the Tuber aestivum-uncinatum model. This truffle is commonly called "Burgundy Truffle" and has a gastronomic and cultural interest.The first part of this thesis focused on the taxonomic status of the Burgundy truffle (Tuber uncinatum). For this, we used a multi-marker approach combining several genetic markers commonly used at the interspecific scale. Our analyses showed that the two taxa, Tuber aestivum (summer truffle) and Tuber uncinatum are conspecific.In the…

pcaH, a molecular marker for estimating the diversity of the protocatechuate-degrading bacterial community in the soil environment

2007

Microorganisms degrading phenolic compounds play an important role in soil carbon cycling as well as in pesticide degradation. The pcaH gene encoding a key ring-cleaving enzyme of the -ketoadipate pathway was selected as a functional marker. Using a degenerate primer pair, pcaH fragments were cloned from two agricultural soils. Restriction fragment length polymorphism (RFLP) screening of 150 pcaH clones yielded 68 RFLP families. Comparison of 86 deduced amino acid sequences displayed 70% identity to known PcaH sequences. Phylogenetic analysis results in two major groups mainly related to PcaH sequences from Actinobacteria and Proteobacteria phyla. This confirms that the developed primer pai…

Molecular community and population studies of arbuscular mycorrhizal fungi (Glomeromycota)

2014

The arbuscular mycorrhizal symbiosis, which appeared at the same time as land plants, 460 million years ago, is a mutualistic beneficial association between most land plants, including those cultivated, and arbuscular mycorrhizal fungi (AMF). AMF, from the Glomeromycota phylum, are widespread soil microorganisms needing a photosynthetic host to complete their life cycle (obligate symbionts). The great potential of plant mineral nutrition improvement and crop production increased during this symbiosis, make AMF an asset in the context of an increase in the demand of world food crop production. The control of that symbiosis by ecology engineering in order to improve ecosystem services, especi…

Genetic polymorphisms and gustatory perception of dietary lipids in the obese subjects

2017

Obesity has become one of most important public health issue in this century. A number of genetic and environmental factors contribute to development of this pathology. Daily dietary intake is also one of the crucial factors. Excessive dietary fat intake has been shown to be critical in the development of obesity. In the last two decades, several studies have shown that oral fat sensing plays an important role in the development of obesity. To prove a relationship between obesity, oral fat sensing and genetic polymorphisms, we recruited children, adolescents and adult subjects from three different populations. To date, CD36 gene encodes the most promising fat taste receptor. Furthermore, we…

[Dietary fatty acids and cancer: potential cellular and molecular mechanisms].

2005

Diversité génétique et aromatique de la truffe de Bourgogne

2013

Truffles are ectomycorrhizal Ascomycota fungi belonging to the Tuberaceae family and more specifically to the Tuber genus. More than thirty Tuber species are currently described in Europe. In this thesis, we specifically focused on the Tuber aestivum-uncinatum model. This truffle is commonly called "Burgundy Truffle" and has a gastronomic and cultural interest.The first part of this thesis focused on the taxonomic status of the Burgundy truffle (Tuber uncinatum). For this, we used a multi-marker approach combining several genetic markers commonly used at the interspecific scale. Our analyses showed that the two taxa, Tuber aestivum (summer truffle) and Tuber uncinatum are conspecific.In the…