Biology subjects

Kelly, M. W.

Publications and source records attributed to Kelly, M. W..

6 recordsLinked to original sources

bioRxiv2026

Daytime heat exposure increases nighttime predation risk in a mangrove gastropod

O_LIThe frequency and intensity of heat events is increasing across marine and terrestrial ecosystems. Within the same ecological community, the relative exposure and sensitivity to heat stress may vary considerably among interacting species, like predators and prey. This can be especially true for species that interact at the aquatic-terrestrial interface, as well as for interactions between primarily nocturnal and diurnal species, making it difficult to predict how such communities will respond to habitat warming. C_LIO_LIThermal limit metrics such as CTmax are often assumed to equate with ecological death because such temperatures impair behavioral activity and/or physiological functioning. Prey that are diurnally active can be more frequently exposed to temperatures that approach CTmax compared to their nocturnal predators, which may use thermal refuges during the day. Yet the impacts of daytime heat exposure on nighttime predation risk remain unknown. C_LIO_LIHere, we compared the thermal environment, performance, and heat tolerance between the predatory blue crab, Callinectus sapidus and one of its prey species, the mangrove periwinkle Littoraria anguilifera in a tropical mangrove ecosystem. We examined how exposing prey to heat stress at and below their CTmax affected their capacity to avoid predation in the field at night when predation risk is highest. C_LIO_LIWe found that acute exposure to temperatures near CTmax during the day increased the prey species susceptibility to predation during recovery at night. Although both interacting predator and prey have high thermal tolerance, prey are exposed to conditions that already reach CTmax, suggesting that current extremes in temperatures may already be influencing vulnerability to predation in this ecosystem. C_LIO_LIOur results suggest that differential exposure to sublethal heat stress in diurnal prey relative to their predator, along with the subsequent impact of these exposures on predation risk, will play a role in shaping these interacting as climate warms. C_LI

ecology↗

bioRxiv2026

A mosaic of climate vulnerability: local warming rates meet intraspecific divergence in heat tolerance

Climate warming is increasing mismatches between thermal phenotypes and habitat temperatures, driving range shifts and population extirpations. While within-species variation in heat tolerance and local warming rates can predict responses to climate warming, how these factors shape differences in vulnerability among taxa and ecosystems is uncertain. Here we combine climate and thermal trait data from 69 species across four ecosystem types to examine the effects of incorporating intraspecific variation in heat tolerance and local warming rates on projected vulnerability to climate warming. Because vulnerability to warming depends on existing phenotypic variation in thermal performance and relative rates of habitat warming, we develop a new metric that integrates localized rates of warming with spatial variation in thermal tolerances, termed the minimum trait velocity. Incorporating intraspecific variation in heat tolerance lowered estimates of warming tolerance (a measure of vulnerability) across most ecosystem types, with the strongest negative impact on marine taxa. Although intraspecific variation in heat tolerance could facilitate adaptation to climate change, our results suggest such variation is generally less than the projected near future warming. This suggests that opportunities for evolutionary rescue via gene flow between locally adapted populations are limited, adding to mounting concern as the climate warms.

ecology↗

bioRxiv2026

The curious case of a Chilean copepod (Tigriopus aff. angulatus) genome assembly

Tigriopus copepods are found in splash pools on all seven continents from the equator to Arctic and Antarctic regions. Given their geographic distribution, frequent exposure to extreme environmental conditions, and strong signatures of local adaptation, these copepods have become models for exploring patterns of adaptation to stressful environments. However, most studies focus on a small subset of Tigriopus species, and there are few genome resources representing the diversity of Tigriopus species and populations. Here, we combine long-read, Pacific Biosciences HiFi data with short-read, Illumina HiC and RNA-seq data to assemble and annotate a genome representing a Tigriopus population from the coast of central Chile. Based on the level of divergence that we observed in mitochondrial genes, we also performed a comparison of morphological characteristics between this population and members of the T. angulatus complex. The assembly that we generated (qhTigAngs1.1.pri) includes 12 major scaffolds (N50 19Mbp, L50 7), equivalent to the number of chromosomes in other Tigriopus species. BUSCO and k-mer analyses of the assembly and BUSCO analyses of gene models are relatively complete (89-99%) with respect to gene or k-mer content. The level of divergence that we observed, morphological differences we recorded, and the spatial distance of this population from the type locality suggest that this Chilean population of Tigriopus may represent a novel species that we call Tigriopus aff. angulatus. These genomic resources will help us understand the diversity and structure of Tigriopus species and populations as well as facilitate future comparisons of adaptation across parallel environmental gradients.

genomics↗

bioRxiv2025

Context matters: A meta-analysis of the variable impact of transgenerational and developmental plasticity on responses to stress

O_LIUnderstanding organisms abilities to adapt and acclimate to stressors in their environments is essential for predicting the distributions and persistence of species and populations during environmental change. Beyond genetic adaptation, prior experiences with a given stressor across life stages can dictate how an individual will fare when exposed to that stressor again. There is now a robust literature on the impacts of parental experiences on offspring traits (transgenerational plasticity), plus an even broader literature on the carry-over effects of early-life experience on phenotypic outcomes (within-generational or developmental plasticity); however, less is understood about the relative strengths of these two forms of plasticity and how they interact to shape stress tolerance. C_LIO_LIWe explored these questions by conducting a meta-analysis of peer-reviewed studies that tested both within- and transgenerational effects of naturally occurring environmental stressors. In particular, we explored contextual moderators or predictor variables including the traits measured, the type of stressor, taxonomic group, and organismal life history traits to elucidate patterns and develop a predictive framework for when we should expect to see effects of transgenerational plasticity, within-generational plasticity, both, or neither. C_LIO_LIWe found that there was not a strong or consistent directional effect of either parental or early-life exposure on subsequent offspring traits. Instead, experimental context (what stressor was used and what traits were measured) as well as biological context (taxonomy, life history traits) were important predictors for understanding the strength and direction of plasticity. We found several contexts where there were meaningful effects of parental and early-life stress exposure and where there was evidence that these may interact to impact phenotypic and fitness outcomes. C_LIO_LIOur study highlights the need for careful consideration of context when exploring patterns of plasticity. We hope to underscore the need for additional, fully factorial studies that measure the interaction between these forms of plasticity across a variety of systems and stressors to better understand how stress may carry forward across life stages and generations. C_LI

ecology↗

bioRxiv2024

Comparative transcriptomic analyses reveal differences in the responses of diploid and triploid eastern oysters to environmental stress during a summer mortality event

Triploid oysters are commonly used as the basis for production in the aquaculture of eastern oysters along the U.S East and Gulf of Mexico coasts. While they are valued for their rapid growth, incidents of triploid mortality during summer months have been well documented in eastern oysters, especially at low salinity sites. We compared global transcriptomic responses of diploid and triploid oysters bred from the same three maternal lines and outplanted to a high (annual mean salinity = 19.4 {+/-} 6.7) and low (annual mean salinity = 9.3 {+/-} 5.0) salinity site at the onset of mortality event in summer of 2021 to test for effect of parental contribution on triploid performance. We compared transcriptomic responses of same diploid and triploid oysters to test for ploidy specific differences in gene expression in response to high and low salinity sites and tested for instances of aneuploidy in experimental triploid oyster lines. Maternal parentage did not affect triploid mortality, but a strong effect of hatchery conditions (cohort) was observed. We detected a higher number of DEGs in response to outplant sites (salinity) and cohorts, indicating stronger influence of these two factors on triploid mortality. At the low salinity site where triploid oysters experienced high mortality, we observed downregulation of transcripts related to calcium signaling (Calmodulin-a, Histidine-rich calcium binding protein (HRC), and cadherin EGF LAG seven-pass G-type receptor 1(CELSR1)), ciliary activity (axonemal and cytoplasmic dyneins), and cell cycle check points (CDK1, HAUS augmin-like complex subunit 3, and MAPKKK, MCM7, SMCs, RTEL1). These transcripts suggest dampening of the salinity stress response and problems during cell division as key contributors to elevated summer mortality in triploid oysters. No instances of aneuploidy were detected in our triploid oyster lines.

evolutionary biology↗

bioRxiv2021

Constitutive gene expression differs in three brain regions important for cognition in neophobic and non-neophobic house sparrows (Passer domesticus)

Neophobia (aversion to new objects, food, and environments) is a personality trait that affects the ability of wildlife to adapt to new challenges and opportunities. Despite the ubiquity and importance of this trait, the molecular mechanisms underlying repeatable individual differences in neophobia in wild animals are poorly understood. We evaluated wild-caught house sparrows (Passer domesticus) for neophobia in the lab using novel object tests. We then selected the most and least neophobic individuals (n=3 of each) and extracted RNA from four brain regions involved in learning, memory, threat perception, and executive function: striatum, dorsomedial hippocampus, medial ventral arcopallium, and caudolateral nidopallium (NCL). Our analysis of differentially expressed genes (DEGs) used 11,889 gene regions annotated in the house sparrow reference genome for which we had an average of 25.7 million mapped reads/sample. PERMANOVA identified significant effects of brain region, phenotype (neophobic vs. non-neophobic), and a brain region by phenotype interaction. Comparing neophobic and non-neophobic birds revealed constitutive differences in DEGs in three of the four brain regions examined: hippocampus (12% of the transcriptome significantly differentially expressed), striatum (4%) and NCL (3%). DEGs included important known neuroendocrine mediators of learning, memory, executive function, and anxiety behavior, including serotonin receptor 5A, dopamine receptors 1, 2 and 5 (downregulated in neophobic birds), and estrogen receptor beta (upregulated in neophobic birds). These results suggest that some of the behavioral differences between phenotypes may be due to underlying gene expression differences in the brain. The large number of DEGs in neophobic and non-neophobic birds also implies that there are major differences in neural function between the two phenotypes that could affect a wide variety of behavioral traits beyond neophobia.

animal behavior and cognition↗