Consequences Of Variation Research Articles

Virus-Induced Epilepsy vs. Epilepsy Patients Acquiring Viral Infection: Unravelling the Complex Relationship for Precision Treatment.

The intricate relationship between viruses and epilepsy involves a bidirectional interaction. Certain viruses can induce epilepsy by infecting the brain, leading to inflammation, damage, or abnormal electrical activity. Conversely, epilepsy patients may be more susceptible to viral infections due to factors, such as compromised immune systems, anticonvulsant drugs, or surgical interventions. Neuroinflammation, a common factor in both scenarios, exhibits onset, duration, intensity, and consequence variations. It can modulate epileptogenesis, increase seizure susceptibility, and impact anticonvulsant drug pharmacokinetics, immune system function, and brain physiology. Viral infections significantly impact the clinical management of epilepsy patients, necessitating a multidisciplinary approach encompassing diagnosis, prevention, and treatment of both conditions. We delved into the dual dynamics of viruses inducing epilepsy and epilepsy patients acquiring viruses, examining the unique features of each case. For virus-induced epilepsy, we specify virus types, elucidate mechanisms of epilepsy induction, emphasize neuroinflammation's impact, and analyze its effects on anticonvulsant drug pharmacokinetics. Conversely, in epilepsy patients acquiring viruses, we detail the acquired virus, its interaction with existing epilepsy, neuroinflammation effects, and changes in anticonvulsant drug pharmacokinetics. Understanding this interplay advances precision therapies for epilepsy during viral infections, providing mechanistic insights, identifying biomarkers and therapeutic targets, and supporting optimized dosing regimens. However, further studies are crucial to validate tools, discover new biomarkers and therapeutic targets, and evaluate targeted therapy safety and efficacy in diverse epilepsy and viral infection scenarios.

Ramadan fasting in the third trimester of pregnancy and postpartum colostrum cortisol concentrations in Morocco.

Breast milk cortisol concentration varies among and within lactating women, but the causes and consequences of variation are not yet fully understood. This study investigated whether maternal fasting from food and water for over 16 h per day during the third trimester of pregnancy was associated with increased concentrations of cortisol in colostrum during the month of Ramadan in a Moroccan sample. Participants were women who gave birth at the public maternity hospital in Rabat, Morocco throughout the month of and month following Ramadan. Participants completed interviews (N = 92), underwent anthropometric assessment (N = 73), and colostrum samples (N = 63) were collected approximately 48-72 h postpartum. Cortisol analysis was completed on a subset of colostrum samples (N = 43). Women were categorized as fasting every day of Ramadan before giving birth (N = 52/92, 57%), fasting some days (N = 29/92, 32%), and not fasting (N = 11/92, 11%). For women who fasted, average fasting duration was 19.5 days (range: 1-29 days), and average time between the last day of fasting and birth was 8.8 days (range: 0-43 days). The number of days of fasting was positively associated with cortisol concentrations in colostrum (p < .009) in a multivariate analysis controlling for maternal anthropometry, hypertension and/or diabetes, and reasons for opting out of fasting. Each day of fasting was associated with a 4.05% increase in colostrum cortisol. Results are consistent with the hypothesis that maternal fasting during the third trimester of pregnancy increases breast milk cortisol and thus alters the hormonal milieu to which the infant is exposed.

Flight Dispersal in Supratidal Rockpool Beetles.

Flight dispersal is ecologically relevant for the survival of supratidal rockpool insects. Dispersal has important consequences for colonisation, gene flow, and evolutionary divergence. Here, we compared the flight dispersal capacity of two congeneric beetle species (Ochthebius quadricollis and Ochthebius lejolisii) that exclusively inhabit these temporary, fragmented, and extreme habitats. We estimated flight capacity and inferred dispersal in both species using different approaches: experimental flying assays, examination of wing morphology, and comparison of microsatellite markers between species. Our findings revealed that both species exhibited similar flight behaviour, with 60 to 80% of the individuals flying under water heating conditions. Notably, females of both species had larger body sizes and wing areas, along with lower wing loading, than males in O. quadricollis. These morphological traits are related to higher dispersal capacity and more energetically efficient flight, which could indicate a female-biassed dispersal pattern. The wing shapes of both species are characterised by relatively larger and narrower wings in relation to other species of the genus, suggesting high flight capacity at short distances. Molecular data revealed in both species low genetic divergences between neighbouring populations, non-significant differences between species, and no isolation by distance effect at the study scale (<100 km). These results point to passive dispersal assisted by wind.

The effects of environmental changes on the endocrine regulation of feeding in fishes.

Fishes are exposed to natural and anthropogenic changes in their environment, which can have major effects on their behaviour and their physiology, including feeding behaviour, food intake and digestive processes. These alterations are owing to the direct action of environmental physico-chemical parameters (i.e. temperature, pH, turbidity) on feeding physiology but can also be a consequence of variations in food availability. Food intake is ultimately regulated by feeding centres of the brain, which receive and process information from endocrine signals from both brain and peripheral tissues such as the gastrointestinal tract. These endocrine signals stimulate or inhibit food intake, and interact with each other to maintain energy homeostasis. Changes in environmental conditions might change feeding habits and rates, thus affecting levels of energy stores, and the expression of endocrine appetite regulators. This review provides an overview of how environmental changes and food availability could affect feeding and these endocrine networks in fishes. This article is part of the theme issue 'Endocrine responses to environmental variation: conceptual approaches and recent developments'.

The fitness consequences of genetic divergence between polymorphic gene arrangements.

Inversions restrict recombination when heterozygous with standard arrangements, but often have few noticeable phenotypic effects. Nevertheless, there are several examples of inversions that can be maintained polymorphic by strong selection under laboratory conditions. A long-standing model for the source of such selection is divergence between arrangements with respect to recessive or partially recessive deleterious mutations, resulting in a selective advantage to heterokaryotypic individuals over homokaryotypes. This paper uses a combination of analytical and numerical methods to investigate this model, for the simple case of an autosomal inversion with multiple independent nucleotide sites subject to mildly deleterious mutations. A complete lack of recombination in heterokaryotypes is assumed, as well as constancy of the frequency of the inversion over space and time. It is shown that a significantly higher mutational load will develop for the less frequent arrangement. A selective advantage to heterokaryotypes is only expected when the two alternative arrangements are nearly equal in frequency, so that their mutational loads are very similar in size. The effects of some Drosophila pseudoobscura polymorphic inversions on fitness traits seem to be too large to be explained by this process, although it may contribute to some of the observed effects. Several population genomic statistics can provide evidence for signatures of a reduced efficacy of selection associated with the rarer of two arrangements, but there is currently little published data that are relevant to the theoretical predictions.

The Shape of Medical Devices Regulation in the United Kingdom? Brexit and Beyond

The United Kingdom’s Medicines and Medical Devices Act (MMD Act) 2021 received royal assent on 11 February 2021. In its passage through parliament, as well as in the accompanying Explanatory Notes, the Act was framed by the government as a necessary post-Brexit bill. Yet prior to this, it was widely presumed that existing statutory instruments, enacted in 2019 to address medical devices regulation in anticipation of a ‘No Deal Brexit’, would provide the United Kingdom (UK) with the necessary legal framework through the transition period and beyond. The European Union (EU) exit legislation included provisions aimed at aligning domestic law with the new EU Medical Devices Regulation (EU MDR) and In Vitro Devices Regulation (EU IVDR) (which were initially due to be implemented during the EU exit transition period). However, just over a year later, at the end of 2020, while the 2021 Act was in the final stages of its parliamentary journey, legislation was introduced that reversed the provisions of the domestic medical device regulations concerning alignment for Great Britain (GB: England, Wales, and Scotland). The result is that the UK now has a dual system of regulation, with Northern Ireland (NI) being governed by the new EU MDR and EU IVDR and GB by older pre-Brexit (yet still EU-derived) law. This article is an attempt to analyse the complex situation now in existence regarding the regulation of medical devices in the UK. To this end, we focus on three main issues. First, we examine the difficulties and challenges presented by the dual system of regulation between NI and GB, highlighting the potentially far-reaching consequences of regulatory divergence between different UK jurisdictions. Second, we ask whether, in the rush to new legislation in 2021, opportunities to properly reform the approach to medical devices were missed. Finally, we look to the future, focusing on the recent Medicine and Healthcare products Regulatory Agency Consultation on the future of medical devices regulation in the UK and the challenges and opportunities that remain.

The unique climate shapes distinct life-history traits of abundant bacteria in Tibetan Plateau grassland soil

The unique geographical patterns of the Qinghai-Tibet Plateau have shaped the different climatic characteristics of the Lhasa and Nyang River watersheds. However, our understanding of climate-dependent life history strategies in riparian grasslands is very limited. In this research, we have compared the causes and consequences of variations in the composition of soil abundant and rare bacterial taxa in the Nyang and Lhasa River watersheds. The results showed that the abundant bacteria, rather than the rare bacteria, exhibited distinct life history strategies between the Lhasa and Nyang watersheds that were a consequence of climate patterns. The wetter climate of the Nyang watershed led to a high ratio of r-strategists among the abundant bacteria (Abundant K:r = 0.323), while in the less favourable climate of the Lhasa watershed, K-strategists were more common among the soil abundant bacteria (Abundant K:r = 0.542). The assembly processes of abundant and rare bacteria in the Lhasa region under relatively harsh climatic conditions seemed to be more affected by variable selection than those in the Nyang region. Moreover, abundant bacteria in the Lhasa region developed stronger potentially cooperative relationships and exhibited a stronger metabolic capacity than those in the Nyang region. The 26 different functional genes identified in LS were highly associated with 38 abundant bacterial species. In contrast, the 16 identified functional genes in NY were highly correlated with 16 abundant bacterial species. These results provide new insights into climate-dependent life history strategies of soil bacterial communities with different abundances in riparian grasslands of the Tibetan Plateau. Contrasting the life history strategies of bacterial taxa with different abundances contributes to a better mechanistic knowledge of their impact on ecosystem functioning under current and future effects of global climate change.

Multi-scale movement syndromes for comparative analyses of animal movement patterns

BackgroundAnimal movement is a behavioral trait shaped by the need to find food and suitable habitat, avoid predators, and reproduce. Using high-resolution tracking data, it is possible to describe movement in greater detail than ever before, which has led to many discoveries about the behavioral strategies of particular species. Recently, enough data been become available to enable a comparative approach, which has the potential to uncover general causes and consequences of variation in movement patterns, but which must be scale specific. MethodsHere we introduce a new multi-scale movement syndrome (MSMS) framework for describing and comparing animal movements and use it to explore the behavior of four sympatric mammals. MSMS incorporates four hierarchical scales of animal movement: (1) fine-scale movement steps which accumulate into (2) daily paths which then, over weeks or months, form a (3) life-history phase. Finally, (4) the lifetime track of an individual consists of multiple life-history phases connected by dispersal or migration events. We suggest a series of metrics to describe patterns of movement at each of these scales and use the first three scales of this framework to compare the movement of 46 animals from four frugivorous mammal species.ResultsWhile subtle differences exist between the four species in their step-level movements, they cluster into three distinct movement syndromes in both path- and life-history phase level analyses. Differences in feeding ecology were a better predictor of movement patterns than a species’ locomotory or sensory adaptations.ConclusionsGiven the role these species play as seed dispersers, these movement syndromes could have important ecosystem implications by affecting the pattern of seed deposition. This multiscale approach provides a hierarchical framework for comparing animal movement for addressing ecological and evolutionary questions. It parallels scales of analyses for resource selection functions, offering the potential to connect movement process with emergent patterns of space use.

Dynamic Evolution of Bacterial Ligand Recognition by Formyl Peptide Receptors.

The detection of invasive pathogens is critical for host immune defense. Cell surface receptors play a key role in the recognition of diverse microbe-associated molecules, triggering leukocyte recruitment, phagocytosis, release of antimicrobial compounds, and cytokine production. The intense evolutionary forces acting on innate immune receptor genes have contributed to their rapid diversification across plants and animals. However, the functional consequences of immune receptor divergence are often unclear. Formyl peptide receptors (FPRs) comprise a family of animal G protein-coupled receptors which are activated in response to a variety of ligands including formylated bacterial peptides, pathogen virulence factors, and host-derived antimicrobial peptides. FPR activation in turn promotes inflammatory signaling and leukocyte migration to sites of infection. Here we investigate patterns of gene loss, diversification, and ligand recognition among FPRs in primates and carnivores. We find that FPR1, which plays a critical role in innate immune defense in humans, has been lost in New World primates. Amino acid variation in FPR1 and FPR2 among primates and carnivores is consistent with a history of repeated positive selection acting on extracellular domains involved in ligand recognition. To assess the consequences of FPR divergence on bacterial ligand interactions, we measured binding between primate FPRs and the FPR agonist Staphylococcus aureus enterotoxin B, as well as S. aureus FLIPr-like, an FPR inhibitor. We found that few rapidly evolving sites in primate FPRs are sufficient to modulate recognition of bacterial proteins, demonstrating how natural selection may serve to tune FPR activation in response to diverse microbial ligands.

Machinability of Selective Laser Melted 17-4 PH Stainless Steel in Turning Process

This paper investigates the machinability of Selective Laser Melted 17-4 Precipitation Hardening Stainless Steel (17-4 PH SS). For this purpose, turning tests were carried out on wrought and SLM specimens and the results were compared. Wear tool, surface roughness, surface integrity and chip morphology were analyzed for both materials. For the tested cutting conditions, the machinability of the SLM material was inferior to that of the commercial material. Dissimilarities in machinability between both materials are a consequence of variations in their microstructures resulting from the manufacturing process.

Reproductive strategies and their consequences for divergence, gene flow, and genetic diversity in three taxa of Clarkia.

Differences in reproductive strategies can have important implications for macro- and micro-evolutionary processes. We used a comparative approach through a population genetics lens to evaluate how three distinct reproductive strategies shape patterns of divergence among as well as gene flow and genetic diversity within three closely related taxa in the genus Clarkia. One taxon is a predominantly autonomous self-fertilizer and the other two taxa are predominantly outcrossing but vary in the primary pollinator they attract. In genotyping populations using genotyping-by-sequencing and comparing loci shared across taxa, our results suggest that differences in reproductive strategies in part promote evolutionary divergence among these closely related taxa. Contrary to expectations, we found that the selfing taxon had the highest levels of heterozygosity but a low rate of polymorphism. The high levels of fixed heterozygosity for a subset of loci suggests this pattern is driven by the presence of structural rearrangements in chromosomes common in other Clarkia taxa. In evaluating patterns within taxa, we found a complex interplay between reproductive strategy and geographic distribution. Differences in the mobility of primary pollinators did not translate to a difference in rates of genetic diversity and gene flow within taxa - a pattern likely due to one taxon having a patchier distribution and a less temporally and spatially reliable pollinator. Taken together, this work advances our understanding of the factors that shape gene flow and the distribution of genetic diversity within and among closely related taxa.

Intelligent Power Control of Inverter Air Conditioners in Power Systems: A Brain Emotional Learning-Based Approach

Inverter air-conditioning (IAC) units have been proved to be effective in frequency regulation by providing flexible capacities. This paper proposes a brain emotional learning (BEL)-based controller to provide the IACs with control signals to be efficiently involved in the frequency regulation in power systems. The BEL-based controller can learn quick-auto, making it appropriate in systems facing uncertainty. To assess the BEL controller performance in realistic conditions, the uncertainties as a consequence of variations in system parameters and load level are considered. The goal is to use the BEL controller to increase the IAC units' ability to track regulation signals accurately in uncertain circumstances. The controller is compared to a fuzzy-PI control, a proportional control scheme, a model predictive control and a linear quadratic regulator control. A delay-dependent stability criterion is used to calculate the highest time delay in the IACs response under which the system maintains stability. In addition, this paper presents an BEL-based coordinator to coordinate the IACs and traditional generation units for compensating considerable frequency variations caused by the time delays. Case studies are accomplished on a multi-area power system in MATLAB/Simulink environment. Eventually, real-time verifications by OPAL-RT real-time digital simulator on the simulated power system are executed to assess the control method.

GaSb/GaAs Type‐II heterojunction GAA‐TFET with core source for enhanced analog/RF performance and reliability

AbstractFor the first time, a novel source extension heterojunction gate‐all‐around tunnel FET (SE‐GAA‐TFET) is proposed and examined using Synopsys TCAD simulator in this manuscript. SE‐GAA‐TFET is found to exhibit improved performance in terms of various analog/RF and DC parameters. As channel/source (C/S) interface and electric field exerted by gate are perpendicular to each other, radius of channel is downscaled to enhance electric filed, without reducing area of the tunneling. Furthermore, the presence of GaSb/GaAs heterojunction at C/S interface leads to reduction in the effective band overlap, which helps a great number of mobile charges to tunnel through C/S boundary at ON‐state. The consequences of variation in different geometrical metrics are evaluated to optimize the device performance. SE‐GAA‐TFET is found to offer a current switching ratio (CSR) of ~1013 along with 32.2 mV dec−1 of average sub‐threshold swing (SSAVG). Furthermore, improvement in transconductance and parasitic capacitance boost the cut‐off frequency of SE‐GAA‐TFET up to 37 GHz. Next, both positive and negative traps are introduced at S/C interface and the study reveals that there is no much deviation in parameters of the transfer characteristics like ION, SSAVG, and IOFF of SE‐GAA‐TFET. Next, proper benchmarking is done to compare the performance of the SE‐GAA‐TFET with similar devices available in literature and it is found that proposed SE‐GAA‐TFET exhibits better DC performance due to improved electrostatic behavior. Finally, SE‐GAA‐TFET is found to offer better fall time along with full‐voltage swing when deployed in a resistive load inverter.

Variability in Plant–Herbivore Interactions

Plants and herbivores are remarkably variable in space and time, and variability has been considered a defining feature of their interactions. Empirical research, however, has traditionally focused on understanding differences in means and overlooked the theoretically significant ecological and evolutionary roles of variability itself. We review the literature with the goal of showing how variability-explicit research expands our perspective on plant–herbivore ecology and evolution. We first clarify terminology for describing variation and then review patterns, causes, and consequences of variation in herbivory across scales of space, time, and biological organization. We consider how incorporating variability improves existing hypotheses and leads to new ones. We conclude by suggesting future work that reports full distributions, integrates effects of variation across scales, describes nonlinearities, and considers how stochastic and deterministic variation combine to determine herbivory distributions.

The association between type of conception through medically assisted reproduction and childhood cognition: a Danish population-wide cohort study.

Previous research has indicated that children conceived through medically assisted reproduction (MAR) generally have cognitive outcomes comparable to or better than naturally conceived children. However, previous studies have been limited in their ability to examine this relationship at a population level and consider variations across different types of MAR. This study utilizes data from all live births in Denmark between 2006 and 2009 (n = 259 608), including a subset of births resulting from MAR conceptions (n = 13 566). The dependent variable is the standardized test scores obtained in the second and third grades of primary schools. A comparison is made between the test scores of children spontaneously conceived (SC) and those conceived through intrauterine insemination (IUI) and assisted reproductive technologies (ART). Ordinary least squares regressions are employed, with a baseline model adjusted only for birth year, as well as models that additionally account for conception-related confounders and sociodemographic family characteristics. In the baseline analysis, ART- and IUI-conceived children displayed better test scores compared with their SC peers. However, after adjusting for relevant factors, ART-conceived children performed worse than SC peers, while IUI-conceived children performed equally well as SC peers and better than ART-conceived children. These results likely reflect differences in the selection process of potential parents into the type of MAR, as well as the consequences of variations in fecundability. Nevertheless, the differences observed across conception types were overshadowed by test score disparities in socioeconomic background.

Consequences of polyploidy and divergence as revealed by cytogenetic mapping of tandem repeats in African clawed frogs (Xenopus, Pipidae)

Repetitive elements have been identified in several amphibian genomes using whole genome sequencing, but few studies have used cytogenetic mapping to visualize these elements in this vertebrate group. Here, we used fluorescence in situ hybridization and genomic data to map the U1 and U2 small nuclear RNAs and histone H3 in six species of African clawed frog (genus Xenopus), including, from subgenus Silurana, the diploid Xenopus tropicalis and its close allotetraploid relative X. calcaratus and, from subgenus Xenopus, the allotetraploid species X. pygmaeus, X. allofraseri, X. laevis, and X. muelleri. Results allowed us to qualitatively evaluate the relative roles of polyploidization and divergence in the evolution of repetitive elements because our focal species include allotetraploid species derived from two independent polyploidization events — one that is relatively young that gave rise to X. calcaratus and another that is older that gave rise to the other (older) allotetraploids. Our results demonstrated conserved loci number and position of signals in the species from subgenus Silurana; allotetraploid X. calcaratus has twice as many signals as diploid X. tropicalis. However, the content of repeats varied among the other allotetraploid species. We detected almost same number of signals in X. muelleri as in X. calcaratus and same number of signals in X. pygmaeus, X. allofraseri, X. laevis as in the diploid X. tropicalis. Overall, these results are consistent with the proposal that allopolyploidization duplicated these tandem repeats and that variation in their copy number was accumulated over time through reduction and expansion in a subset of the older allopolyploids.

What Darwin could not see: island formation and historical sea levels shape genetic divergence and island biogeography in a coastal marine species

Oceanic islands play a central role in the study of evolution and island biogeography. The Galapagos Islands are one of the most studied oceanic archipelagos but research has almost exclusively focused on terrestrial organisms compared to marine species. Here we used the Galapagos bullhead shark (Heterodontus quoyi) and single nucleotide polymorphisms (SNPs) to examine evolutionary processes and their consequences for genetic divergence and island biogeography in a shallow-water marine species without larval dispersal. The sequential separation of individual islands from a central island cluster gradually established different ocean depths between islands that pose barriers to dispersal in H. quoyi. Isolation by resistance analysis suggested that ocean bathymetry and historical sea level fluctuations modified genetic connectivity. These processes resulted in at least three genetic clusters that exhibit low genetic diversity and effective population sizes that scale with island size and the level of geographic isolation. Our results exemplify that island formation and climatic cycles shape genetic divergence and biogeography of coastal marine organisms with limited dispersal comparable to terrestrial taxa. Because similar scenarios exist in oceanic islands around the globe our research provides a new perspective on marine evolution and biogeography with implications for the conservation of island biodiversity.

Self-regulation of peer feedback quality aspects through different dimensions of experience within prior peer feedback assignments

Although peer review is a widely-used pedagogical technique, its value depends upon the quality of the reviews that students produce, and much research remains to be done to systematically study the nature, causes, and consequences of variation in peer review quality. We propose a new framework that conceptualizes five larger dimensions of peer review quality and then present a study that investigated three specific peer review quality constructs in a large dataset and further explored how these constructs change through different types of self-regulation peer reviewing experiences. Peer review data across multiple assignments were analyzed from 2,092 undergraduate students enrolled in one of three offerings of a biology course at a large public research university in the United States. Peer review quality was measured in terms of comment amount, comment accuracy, and rating accuracy; the measures of reviewing experience focused upon self-regulated learning factors such as practice, feedback, others’ modeling, and relative performance. Meta-correlation (for testing reliability, separability, and stability) and meta-regression (as a time-series analysis for testing the relationship of changes across assignments in reviewing quality with experiences as reviewer and reviewee) are used to establish the robustness of effects and meaningful variation of effects across course offerings and assignments. Results showed that there were three meaningful review quality constructs (i.e., were measured reliably, separable, and semi-stable over time). Further, all three showed changes in response to previous reviewer and reviewee experiences, but only feedback helpfulness, in particular, showed effects of all four examined types of self-regluation experiences (practice, feedback, others’ modeling, and relative performance). The findings suggest that instructors can improve review quality by providing comment prompt scaffolds that lead to longer comments as well as by matching authors with similarly performing reviewers.

Cylindrical void growth vs. grain fragmentation in FCC single crystals: CPFEM study for two types of loading conditions

The crystal plasticity finite element method (CPFEM) is used to investigate the coupling between the cylindrical void growth or collapse and grain refinement in face-centred cubic (FCC) single crystals. A 2D plane strain model with one void is used. The effect of the initial lattice orientation, similarities, and differences between stress- and strain-driven loading scenarios are explored. To this end, boundary conditions are enforced in two different ways. The first one is based on maintaining constant in-plane stress biaxiality via a dedicated truss element, while the second one is imposing a constant displacement biaxiality factor. Uniaxial and biaxial loading cases are studied. For the uniaxial loading case a special configuration, which enforces an equivalent pattern of plastic deformation in the pristine crystal, is selected in order to investigate the mutual interactions between the evolving void and the developed lattice rotation heterogeneity. Next, biaxial loading cases are considered for three crystal orientations, one of which is not symmetric with respect to loading directions. It is analysed how stress or strain biaxility factors and initial lattice orientation influence the void evolution in terms of its size and shape. Moreover, the consequences of variations in the resulting heterogeneity of lattice rotation are studied in the context of the grain refinement phenomenon accompanying the void evolution. Scenarios that may lead to more advanced grain fragmentation are identified.

Evolutionary Quantitative Proteomics of Reproductive Protein Divergence in Drosophila

Reproductive traits often evolve rapidly between species. Understanding the causes and consequences of this rapid divergence requires characterization of female and male reproductive proteins and their effect on fertilization success. Species in the Drosophila virilis clade exhibit rampant interspecific reproductive incompatibilities, making them ideal for studies on diversification of reproductive proteins and their role in speciation. Importantly, the role of intraejaculate protein abundance and allocation in interspecific divergence is poorly understood. Here, we identify and quantify the transferred male ejaculate proteome using multiplexed isobaric labeling of the lower female reproductive tract before and immediately after mating using three species of the virilis group. We identified over 200 putative male ejaculate proteins, many of which show differential abundance between species, suggesting that males transfer a species-specific allocation of seminal fluid proteins during copulation. We also identified over 2000 female reproductive proteins, which contain female-specific serine-type endopeptidases that showed differential abundance between species and elevated rates of molecular evolution, similar to that of some male seminal fluid proteins. Our findings suggest that reproductive protein divergence can also manifest in terms of species-specific protein abundance patterns.