Biology subjects

DiLeo, M. F.

Publications and source records attributed to DiLeo, M. F..

5 recordsLinked to original sources

bioRxiv2024

Clear effects of population and sex but not rearing temperature on stress tolerance in a temperate butterfly

As temperatures are rising globally, the survival of organisms depends on their tolerance of such rising temperatures as well as resistance to indirect effects such as resource shortage under these new conditions. Genetic background and phenotypic plasticity in the form of acclimation are known to affect stress resistance, but much about genetic variation in plasticity is still unknown, especially in insects other than Drosophila. Here we aim to study the effect of population of origin, developmental temperature, and their interaction on stress tolerance (heat tolerance and starvation resistance). We test the beneficial acclimation hypothesis and how it is influenced by intraspecific differences. For this, we reared Glanville fritillary butterfly larvae originating from Finland and Spain at high and control temperatures, and measured their heat tolerance and starvation resistance. To assess potential costs of acclimation we also measured lifespan under control conditions. Neither adult heat tolerance nor starvation resistance were impacted by thermal conditions during development and thus we found no evidence for the beneficial acclimation hypothesis. Heat tolerance also did not differ between sex or population of origin. In contrast, we found interacting effects of population and sex on adult starvation resistance, with Spanish females outperforming other groups. Spanish females also had a longer lifespan under control conditions. Our study provides no evidence for the beneficial acclimation hypothesis but highlights the importance of population differences in stress tolerance. SUMMARY STATEMENTDespite their importance, the interacting effects of population of origin and developmental acclimation temperature on stress response have not often been studied together, especially in insects other than Drosophila.

evolutionary biology↗

bioRxiv2020

Improved chromosome level genome assembly of the Glanville fritillary butterfly (Melitaea cinxia) based on SMRT Sequencing and linkage map.

The Glanville fritillary (Melitaea cinxia) butterfly is a long-term model system for metapopulation dynamics research in fragmented landscapes. Here, we provide a chromosome level assembly of the butterflys genome produced from Pacific Biosciences sequencing of a pool of males, combined with a linkage map from population crosses. The final assembly size of 484 Mb is an increase of 94 Mb on the previously published genome. Estimation of the completeness of the genome with BUSCO, indicates that the genome contains 93 - 95% of the BUSCO genes in complete and single copies. We predicted 14,830 gene models using the MAKER pipeline and manually curated 1,232 of these gene models. The genome and its annotated gene models are a valuable resource for future comparative genomics, molecular biology, transcriptome and genetics studies on this species.

genomics↗

bioRxiv2020

Narrow oviposition preference of an insect herbivore risks survival under conditions of severe drought

O_LIUnderstanding species habitat preferences are crucial to predict organisms responses to the current climate crisis. In many insects, maternal habitat selection for oviposition essentially determines offspring performance. Whether changes in climatic conditions may pose future mismatches in oviposition preference and offspring performance when mothers continue to prefer microhabitats that now threaten offspring survival is an open question. C_LIO_LITo address this, we tested if oviposition preferences put offspring at risk in the Glanville fritillary butterfly (Melitaea cinxia) under drought stress. Mainly, we focus on identifying the microhabitat determinants for oviposition and the variation of conditions experienced by the sessile offspring, using field observations from 12 populations collected over 2015-2018. These data are combined with ten years of larval nest and precipitation data to understand within-population patterns of habitat selection. We tested whether the preferred microhabitats maximized the extended larval performance (i.e. overwinter survival). C_LIO_LIWe found that females preferentially oviposited in microhabitats with higher host plant abundance and higher proportion of host plants with signs of drought stress. In most years, larval nests had higher survival in these drought-stressed microhabitats. However, in an extremely dry year, only two nests survived over the summer. C_LIO_LIOur results highlight that a failure to shift habitat preference under extreme climate conditions may have drastic consequences for the survival of natural populations under changing climatic conditions. C_LI

ecology↗

bioRxiv2019

Summer drought decreases the predictability of local extinctions in a butterfly metapopulation

The ecological impacts of extreme climatic events on population dynamics and/or community composition are profound and predominantly negative. Here, using extensive data of an ecological model system, we test whether predictions from ecological models remain robust when environmental conditions are outside the bounds of observation. First, we report a 10-fold demographic decline of the Glanville fritillary butterfly metapopulation on the [A]land islands (Finland). Next, using climatic and satellite data we show that the summer of 2018 was an anomaly in terms of water balance and vegetation productivity indices across the habitats of the butterfly, and demonstrate that population growth rates are strongly associated with spatio-temporal variation in climatic water balance. Finally, we demonstrate that covariates that have previously been identified to impact the extinction probability of local populations in this system are less informative when populations are exposed to (severe) drought during the summer months. Our results highlight the unpredictable responses of natural populations to extreme climatic events.

ecology↗

bioRxiv2018

Landscape permeability and individual variation in a dispersal-linked gene jointly determine genetic structure in the Glanville fritillary butterfly

There is now clear evidence that species across a broad range of taxa harbour extensive heritable variation in dispersal. While studies suggest that this variation can facilitate demographic outcomes such as range expansion and invasions, few have considered the consequences of intraspecific variation in dispersal for the maintenance and distribution of genetic variation across fragmented landscapes. Here we examine how landscape characteristics and individual variation in dispersal combine to predict genetic structure using genomic and spatial data from the Glanville fritillary butterfly. We used linear and latent factor mixed models to identify the landscape features that best predict spatial sorting of alleles in the dispersal-related gene phosphoglucose isomerase (Pgi). We next used structural equation modeling to test if variation in Pgi mediated gene flow as measured by Fst at putatively neutral loci. In a year when the population was expanding following a large decline, individuals with a genotype associated with greater dispersal ability were found at significantly higher frequencies in populations isolated by water and forest, and these populations showed lower levels of genetic differentiation at neutral loci. These relationships disappeared in the next year when metapopulation density was high, suggesting that the effects of individual variation are context dependent. Together our results highlight that 1) more complex aspects of landscape structure beyond just the configuration of habitat can be important for maintaining spatial variation in dispersal traits, and 2) that individual variation in dispersal plays a key role in maintaining genetic variation across fragmented landscapes.\n\nImpact summaryUnderstanding how fragmentation affects dispersal and gene flow across human-modified landscapes has long been a goal in evolutionary biology. It is typically assumed that individuals of the same species respond to the landscape in the same way, however growing evidence suggests that individuals can vary considerably in their dispersal traits. While the effects of this individual dispersal variation on range expansions and invasions have been well-characterized, knowledge of how it might mediate genetic responses to landscape fragmentation are almost entirely lacking. Here we demonstrate that individual variation in dispersal is key to the maintenance of genetic variation during a population expansion following a large decline in a butterfly metapopulation. We further show that spatial variation in dispersal is not maintained by the configuration of habitat patches alone, but by a more complex genotype-environment interaction involving the landscape matrix (i.e. landscape features found between habitat patches). This challenges the simplified landscape representations typically used in studies of dispersal evolution that ignore heterogeneity in the landscape matrix. More broadly, our results highlight the interplay of adaptive and neutral processes across fragmented landscapes, suggesting that an understanding of species vulnerability to landscape fragmentation requires consideration of both.

evolutionary biology↗