Germline proliferation trades off with lipid metabolism in .

Little is known about the metabolic basis of life-history trade-offs but lipid stores seem to play a pivotal role. During reproduction, an energetically highly costly process, animals mobilize fat reserves. Conversely, reduced or curtailed reproduction promotes lipid storage in many animals.

Wolbachia effects on thermal preference of natural Drosophila melanogaster are influenced by host genetic background, Wolbachia type, and bacterial titer.

Temperature plays a fundamental role in the fitness of all organisms. In particular, it strongly affects metabolism and reproduction in ectotherms that have limited physiological capabilities to regulate their body temperature. The influence of temperature variation on the physiology and behaviour of ectotherms is well studied but we still know little about the influence of symbiotic interactions on thermal preference (T ) of the host.

Historic Museum Samples Provide Evidence for a Recent Replacement of Wolbachia Types in European Drosophila melanogaster.

Wolbachia is one of the most common bacterial endosymbionts, which is frequently found in numerous arthropods and nematode taxa. Wolbachia infections can have a strong influence on the evolutionary dynamics of their hosts since these bacteria are reproductive manipulators that affect the fitness and life history of their host species for their own benefit. Host-symbiont interactions with Wolbachia are perhaps best studied in the model organism Drosophila melanogaster, which is naturally infected with at least 5 different variants among which wMel and wMelCS are the most frequent ones.

Geographic Variation in Genomic Signals of Admixture Between Two Closely Related European Sepsid Fly Species.

Unlabelled: The extent of interspecific gene flow and its consequences for the initiation, maintenance, and breakdown of species barriers in natural systems remain poorly understood. Interspecific gene flow by hybridization may weaken adaptive divergence, but can be overcome by selection against hybrids, which may ultimately promote reinforcement. An informative step towards understanding the role of gene flow during speciation is to describe patterns of past gene flow among extant species.

Wolbachia has subtle effects on thermal preference in highly inbred Drosophila melanogaster which vary with life stage and environmental conditions.

Temperature fluctuations are challenging for ectotherms which are not able to regulate body temperature by physiological means and thus have to adjust their thermal environment via behavior. However, little is yet known about whether microbial symbionts influence thermal preference (T) in ectotherms by modulating their physiology. Several recent studies have demonstrated substantial effects of Wolbachia infections on host T in different Drosophila species.

Unveiling Subtle Geographical Clines: Phenotypic Effects and Dynamics of Circadian Clock Gene Polymorphisms.

Our understanding of the gene regulatory network that constitutes the circadian clock has greatly increased in recent decades, notably due to the use of as a model system. In contrast, the analysis of natural genetic variation that enables the robust function of the clock under a broad range of environments has developed more slowly. In the current study, we analyzed comprehensive genome sequencing data from wild European populations of , which were densely sampled through time and space.

An Ancestral Balanced Inversion Polymorphism Confers Global Adaptation.

Since the pioneering work of Dobzhansky in the 1930s and 1940s, many chromosomal inversions have been identified, but how they contribute to adaptation remains poorly understood. In Drosophila melanogaster, the widespread inversion polymorphism In(3R)Payne underpins latitudinal clines in fitness traits on multiple continents. Here, we use single-individual whole-genome sequencing, transcriptomics, and published sequencing data to study the population genomics of this inversion on four continents: in its ancestral African range and in derived populations in Europe, North America, and Australia.

Temperature-dependent melanism and phenoloxidase activity in the dimorphic sepsid fly Sepsis thoracica.

Climate is changing towards both higher average temperatures and more frequent and severe heat waves. Whereas numerous studies have investigated temperature effects on animal life histories, assessments of their immune function are limited. In the size- and colour-dimorphic black scavenger (or dung) fly Sepsis thoracica (Diptera: Sepsidae), we experimentally studied how developmental temperature and larval density influence phenoloxidase (PO) activity, a key enzyme in insect pigmentation, thermoregulation, and immunity.

Effects of social organization and elevation on spatial genetic structure in a montane ant.

Studying patterns of population structure across the landscape sheds light on dispersal and demographic processes, which helps to inform conservation decisions. Here, we study how social organization and landscape factors affect spatial patterns of genetic differentiation in an ant species living in mountainous regions. Using genome-wide SNP markers, we assess population structure in the Alpine silver ant, .

Complex effects of environment and Wolbachia infections on the life history of Drosophila melanogaster hosts.

Wolbachia bacteria are common endosymbionts of many arthropods found in gonads and various somatic tissues. They manipulate host reproduction to enhance their transmission and confer complex effects on fitness-related traits. Some of these effects can serve to increase the survival and transmission efficiency of Wolbachia in the host population.

Restriction of Bacteria in Early Embryogenesis of Neotropical Species via Endoplasmic Reticulum-Mediated Autophagy.

are maternally transmitted intracellular bacteria that are not only restricted to the reproductive organs but also found in various somatic tissues of their native hosts. The abundance of the endosymbiont in the soma, usually a dead end for vertically transmitted bacteria, causes a multitude of effects on life history traits of their hosts, which are still not well understood. Thus, deciphering the host-symbiont interactions on a cellular level throughout a host's life cycle is of great importance to understand their homeostatic nature, persistence, and spreading success.

Drosophila Evolution over Space and Time (DEST): A New Population Genomics Resource.

Drosophila melanogaster is a leading model in population genetics and genomics, and a growing number of whole-genome data sets from natural populations of this species have been published over the last years. A major challenge is the integration of disparate data sets, 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.

The discovery, distribution, and diversity of DNA viruses associated with in Europe.

is an important model for antiviral immunity in arthropods, but very few DNA viruses have been described from the family Drosophilidae. This deficiency limits our opportunity to use natural host-pathogen combinations in experimental studies, and may bias our understanding of the virome. Here, we report fourteen DNA viruses detected in a metagenomic analysis of 6668 pool-sequenced , sampled from forty-seven European locations between 2014 and 2016.

Global population genetic structure and demographic trajectories of the black soldier fly, Hermetia illucens.

Background: The black soldier fly (Hermetia illucens) is the most promising insect candidate for nutrient-recycling through bioconversion of organic waste into biomass, thereby improving sustainability of protein supplies for animal feed and facilitating transition to a circular economy. Contrary to conventional livestock, genetic resources of farmed insects remain poorly characterised. We present the first comprehensive population genetic characterisation of H.

Allelic polymorphism at foxo contributes to local adaptation in Drosophila melanogaster.

The insulin/insulin-like growth factor signalling pathway has been hypothesized as a major determinant of life-history profiles that vary adaptively in natural populations. In Drosophila melanogaster, multiple components of this pathway vary predictably with latitude; this includes foxo, a conserved gene that regulates insulin signalling and has pleiotropic effects on a variety of fitness-associated traits. We hypothesized that allelic variation at foxo contributes to genetic variance for size-related traits that vary adaptively with latitude.

The Genomic Architecture of Adaptation to Larval Malnutrition Points to a Trade-off with Adult Starvation Resistance in Drosophila.

Periods of nutrient shortage impose strong selection on animal populations. Experimental studies of genetic adaptation to nutrient shortage largely focus on resistance to acute starvation at adult stage; it is not clear how conclusions drawn from these studies extrapolate to other forms of nutritional stress. We studied the genomic signature of adaptation to chronic juvenile malnutrition in six populations of Drosophila melanogaster evolved for 150 generations on an extremely nutrient-poor larval diet.

Demographic analyses of a new sample of haploid genomes from a Swedish population of Drosophila melanogaster.

European and African natural populations of Drosophila melanogaster have been the focus of several studies aiming at inferring demographic and adaptive processes based on genetic variation data. However, in these analyses little attention has been given to gene flow between African and European samples. Here we present a dataset consisting of 14 fully sequenced haploid genomes sampled from a natural population from the northern species range (Umeå, Sweden).

Genomic Analysis of European Drosophila melanogaster Populations Reveals Longitudinal Structure, Continent-Wide Selection, and Previously Unknown DNA Viruses.

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.

Common structuring principles of the Drosophila melanogaster microbiome on a continental scale and between host and substrate.

The relative importance of host control, environmental effects and stochasticity in the assemblage of host-associated microbiomes is being debated. We analysed the microbiome among fly populations that were sampled across Europe by the European Drosophila Population Genomics Consortium (DrosEU). In order to better understand the structuring principles of the natural D.

Population Genomics on the Fly: Recent Advances in Drosophila.

Drosophila melanogaster, a small dipteran of African origin, represents one of the best-studied model organisms. Early work in this system has uniquely shed light on the basic principles of genetics and resulted in a versatile collection of genetic tools that allow to uncover mechanistic links between genotype and phenotype. Moreover, given its worldwide distribution in diverse habitats and its moderate genome-size, Drosophila has proven very powerful for population genetics inference and was one of the first eukaryotes whose genome was fully sequenced.

Distinct genomic signals of lifespan and life history evolution in response to postponed reproduction and larval diet in .

Reproduction and diet are two major factors controlling the physiology of aging and life history, but how they interact to affect the evolution of longevity is unknown. Moreover, although studies of large-effect mutants suggest an important role of nutrient sensing pathways in regulating aging, the genetic basis of evolutionary changes in lifespan remains poorly understood. To address these questions, we analyzed the genomes of experimentally evolved populations subjected to a factorial combination of two selection regimes: reproductive age (early versus postponed), and diet during the larval stage ("low," "control," "high"), resulting in six treatment combinations with four replicate populations each.

Altering the Temporal Regulation of One Transcription Factor Drives Evolutionary Trade-Offs between Head Sensory Organs.

Size trade-offs of visual versus olfactory organs is a pervasive feature of animal evolution. This could result from genetic or functional constraints. We demonstrate that head sensory organ size trade-offs in Drosophila are genetically encoded and arise through differential subdivision of the head primordium into visual versus non-visual fields.

A clinal polymorphism in the insulin signaling transcription factor foxo contributes to life-history adaptation in Drosophila.

A fundamental aim of adaptation genomics is to identify polymorphisms that underpin variation in fitness traits. In Drosophila melanogaster, latitudinal life-history clines exist on multiple continents and make an excellent system for dissecting the genetics of adaptation. We have previously identified numerous clinal single-nucleotide polymorphism in insulin/insulin-like growth factor signaling (IIS), a pathway known from mutant studies to affect life history.