Search results for "ogas"
showing 10 items of 902 documents
Genomic Analysis of European Drosophila melanogaster Populations Reveals Longitudinal Structure, Continent-Wide Selection, and Previously Unknown DNA…
2020
Genetic variation is the fuel of evolution, with standing genetic variation especially important for short-term evolution and local adaptation. To date, studies of spatiotemporal patterns of genetic variation in natural populations have been challenging, as comprehensive sampling is logistically difficult, and sequencing of entire populations costly. Here, we address these issues using a collaborative approach, sequencing 48 pooled population samples from 32 locations, and perform the first continent-wide genomic analysis of genetic variation in European Drosophila melanogaster. Our analyses uncover longitudinal population structure, provide evidence for continent-wide selective sweeps, ide…
Assessing Methane Emission and Economic Viability of Energy Exploitation in a Typical Sicilian Municipal Solid Waste Landfill
2018
Sanitary landfills for municipal solid waste (MSW) represent one of the major anthropogenic source of GHGs emissions and are directly responsible of the climate changes we are facing nowadays. Indeed, the biodegradable organic matter of MSW undergoes anaerobic digestion producing the landfill gas (LFG), whose main components are CH4 and CO2. Therefore, biomethane energy exploitation in MSW landfills will reduce GHGs emission positively affecting the global warming. The aim of the present study was to assess the methane production in a Sicilian landfill by comparing the results from field measurements of methane emission and the estimates achieved by applying different mathematical models. A…
Selection for reproduction under short photoperiods changes diapause-associated traits and induces widespread genomic divergence.
2019
The work has been supported by the Academyof Finland to A.H. (project 267244) and Natural Environment Research Council (NERC) funding (NE/J020818/1 to M.G.R.; NE/L501852/1 to R.A.W.W.). The incidence of reproductive diapause is a critical aspect of life history in overwintering insects from temperate regions. Much has been learned about the timing, physiology and genetics of diapause in a range of insects, but how the multiple changes involved in this and other photoperiodically regulated traits are inter-related is not well understood. We performed quasinatural selection on reproduction under short photoperiods in a northern fly species, Drosophila montana, to trace the effects of photoper…
Distinct protoconchs recognised in three of the larger Mediterranean Cerithium species (Caenogastropoda: Cerithiidae)
2017
The gastropod genus Cerithium includes several polymorphic species which are hardly distinguishable using a morphological approach based on teleoconch characters. Here we show that protoconch characters can be reliably used to identify the larger Mediterranean species (Cerithium alucastrum, C. repandum and C. vulgatum), and to assess their intraspecific variability. Based on a large amount of morphological data, we show that a multispiral, strongly sculptured protoconch (traditionally associated with C. vulgatum) is found in C. alucastrum. This species originated in the Pliocene. A multispiral, weakly sculptured protoconch, not observed previously, is reported for C. vulgatum. A paucispiral…
Acclimatised rumen culture for raw microalgae conversion into biogas: Linking microbial community structure and operational parameters in anaerobic m…
2019
[EN] Ruminal fluid was inoculated in an Anaerobic Membrane Reactor (AnMBR) to produce biogas from raw Scenedesmus. This work explores the microbial ecology of the system during stable operation at different solids retention times (SRT). The 16S rRNA amplicon analysis revealed that the acclimatised community was mainly composed of Anaerolineaceae, Spirochaetaceae, Lentimicrobiaceae and Cloacimonetes fermentative and hydrolytic members. During the highest biodegradability achieved in the AnMBR (62%) the dominant microorganisms were Fervidobacterium and Methanosaeta. Different microbial community clusters were observed at different SRT conditions. Interestingly, syntrophic bacteria Gelria and …
Cuticular hydrocarbons as potential mediators of cryptic species divergence in a mutualistic ant association
2019
International audience; Upon advances in sequencing techniques, more and more morphologically identical organisms are identified as cryptic species. Often, mutualistic interactions are proposed as drivers of diversification. Species of the neotropical parabiotic ant association between Crematogaster levior and Camponotus femoratus are known for highly diverse cuticular hydrocarbon (CHC) profiles, which in insects serve as desiccation barrier but also as communication cues. In the present study, we investigated the association of the ants' CHC profiles with genotypes and morphological traits, and discovered cryptic species pairs in both genera. To assess putative niche differentiation betwee…
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…
Volatile components of ripe fruits of Morinda citrifolia and their effects on Drosophila
1996
Abstract The only larval resource of the specialist species, Drosophila sechellia , is ripe fruits of Morinda citrifolia . The chemical composition of this fruit, which is very toxic to most Drosophila species, was investigated and 51 compounds were abundant enough to be identified by GC-MS. The ripe fruit is characterized by a large amount of carboxylic acids, especially octanoic and hexanoic acids. The biological effects of the ripe fruit and its main acids were investigated with behavioural studies. Octanoic acid is responsible for the general toxicity of the fruit to most Drosophila species; D. sechellia is the only species which is resistant to this acid. Hexanoic acid has a unique eff…
Topical bioassay of Oberon® on Drosophila melanogaster pupae: delayed effects on ovarian proteins, cuticular hydrocarbons and sexual behaviour
2021
International audience; Spiromesifen (Oberon? 240 SC; concentrated solution; Bayer CropScience, Germany) a pesticide derived from spirocyclic tetronic acids, acts mainly though blocking lipid biosynthesis via acetyl-CoA carboxylase. However, its mode of action requires further analyses. This study aims to evaluate the sublethal effects of spiromesifen on the fruit fly Drosophila melanogaster. The treatment was carried out by topical application on newly moulted pupae using two concentrations (LD10 = 21.45 and LD25 = 39.53 ?g a.i./pupa). Our results showed that the developmental duration of larvae and pupae were not significantly affected by treatment. However, spiromesifen caused delayed ef…
Drosophila Evolution over Space and Time (DEST) : A New Population Genomics Resource
2021
Drosophila melanogaster is a leading model in population genetics and genomics, and a growing number of whole-genome datasets from natural populations of this species have been published over the last years. A major challenge is the integration of disparate datasets, often generated using different sequencing technologies and bioinformatic pipelines, which hampers our ability to address questions about the evolution of this species. Here we address these issues by developing a bioinformatics pipeline that maps pooled sequencing (Pool-Seq) reads from D. melanogaster to a hologenome consisting of fly and symbiont genomes and estimates allele frequencies using either a heuristic (PoolSNP) or a…