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Biology subjects

Uy, F. M. K.

Publications and source records attributed to Uy, F. M. K..

6 recordsLinked to original sources

Adaptive genomic variation is linked to a climatic gradient in a social wasp

Species vary in their ability to adapt to rapid changes, with the presence of genetic variation often facilitating long-term evolutionary responses. Given the impending threat of climate change, it is critical to investigate how genetic variation facilitates persistence and possible range expansion in animals. Here, we combine genomic and climatic data to characterize the drivers of local adaptation in the widely distributed, social wasp Mischocyttarus mexicanus cubicola. Using whole genome sequence data, we show that adaptive genomic variation is linked to a climatic gradient across the broad distribution of this species. We found strong population structure, dividing the species into two genetic clusters that follow subtropical and temperate regions. Patterns of gene flow across the range deviate from those expected by isolation by distance alone with climatic differences resulting in reduced gene flow even between adjacent populations. Importantly, genotype-environment analyses reveal candidate single nucleotide polymorphism (SNPs) associated with temperature and rainfall, suggesting adaptation for thermal and desiccation tolerance. In particular, candidate SNPs in or near mitochondrial genes ND5, CO1, and COIII are linked to cold tolerance and metabolism. Similarly, the Gld nuclear gene shown to mediate cold hardiness and cuticle formation, shows two candidate SNPs with non-synonymous mutations unique to temperate populations. Together, our results reveal candidate SNPs consistent with local adaptation to distinct climatic conditions. Thus, the integration of genomic and climatic data can be a powerful approach to predict vulnerability and persistence of species under rapid climate change.

evolutionary biology↗

Caste, sex, and parasitism influence brain plasticity in a social wasp

Phenotypic plasticity is the capacity of a single genotype to exhibit different phenotypes, and can be an adaptive response to specific environmental and social conditions. Social insects are particularly well-suited to study plasticity, because the division of labor amongst females and the different life histories of males and females are associated with specific sensory needs. Here, we take advantage of the social wasp Polistes dominula to explore if brain plasticity is influenced by caste and sex, and the exploitation by the parasite Xenos vesparum. Within sexes, males had proportionally larger optic lobes, while females, regardless of caste, had larger antennal lobes, which is consistent with sensory needs of sex-specific life histories. Within castes, reproductive females had larger calyces, as predicted by their sensory needs for extensive within-colony interactions and forming winter aggregations, than workers who spend more time foraging for nest material and prey. Surprisingly, parasites had different effects on female and male hosts. Female workers were castrated and behaviorally manipulated by female or male parasites, but only showed moderate differences in relative allocation of different brain tissue compared to non-parasitized workers. In contrast, the testes and behavior of parasitized males were essentially unaffected, but they had smaller brains and greater relative volume of most sensory brain regions than non-parasitized males. Our results are consistent with caste and sex mediating brain plasticity in P. dominula and that the parasites manipulation can also drive differential allocation of brain regions depending on host sex.

neuroscience↗

Evidence for a selective link between cooperation and individual recognition

The ability to recognize and discriminate among others is a frequent assumption of models of the evolution of cooperative behavior. At the same time, cooperative behavior has been proposed as a selective agent favoring the evolution of individual recognition abilities. While theory predicts that recognition and cooperation may co-evolve, data linking recognition abilities and cooperative behavior with fitness or evidence of selection are elusive. Here, we provide evidence of a fitness link between individual recognition and cooperation in the paper wasp Polistes fuscatus. Nest founding females in northern populations frequently form cooperative multiple foundress nests and possess highly variable facial patterns that mediate individual recognition. We describe a dearth of cooperative nesting, low phenotypic diversity, and a lack of individual recognition in southern populations. In a common garden experiment, northern co-foundress associations successfully reared offspring while all cooperative southern groups failed to rear any offspring, suggesting a fitness link between individual recognition and successful cooperation. Consistent with a selective link between individual recognition and cooperation, we find that rates of cooperative co-nesting correlate with identity-signaling color pattern diversity across the species range. Moreover, genomic evidence of recent positive selection on cognition loci likely to mediate individual recognition is substantially stronger in northern compared to southern P. fuscatus populations. Collectively, these data suggest that individual recognition and cooperative nesting behavior have co-evolved in P. fuscatus because recognition helps mediate conflict among co-nesting foundresses. This work provides evidence of a specific cognitive phenotype under selection because of social interactions, supporting the idea that social behavior can be a key driver of cognitive evolution.

animal behavior and cognition↗

Differential investment in visual and olfactory brain regions mirrors the sensory needs of a paper wasp social parasite and its host

Obligate social parasites evolve traits to effectively locate and then exploit their hosts, whereas hosts have complex social behavioral repertoires, which include sensory recognition to reject potential conspecific intruders and heterospecific parasites. While social parasite and host behaviors have been studied extensively, less is known about how their sensory systems function to meet their specific selective pressures. Here, we compare investment in visual and olfactory brain regions in the paper wasp Polistes dominula, and its obligate social parasite P. sulcifer, to explore the link between sensory systems and brain plasticity. Our results show opposite and significant differences, consistent with their very different life-histories, in the sensory investments between these two closely-related species. Social parasites initially invest in the optic lobes to likely locate their hosts. After host colony usurpation, the parasite increases its brain volume, with specific investment in antennal lobes, which mirrors the behavioral switch from a usurping parasite to an integrated parasitic queen of the host colony. Contrastingly, hosts initially invest in the antennal lobes and sensory processing compared to social parasites, as predicted by their need to maintain social cohesion, allocate colony tasks, and recognize con- and heterospecific intruders. Host queens show a trend of higher investment in all sensory brain regions compared to workers, paralleling differences in task allocations. Our work provides novel insights into how intraspecific brain plasticity can facilitate the unique sensory adaptations needed to perform specific tasks by the host or to transition from searching to successful host exploitation by the social parasite.

neuroscience↗

Shared transcriptional responses to con- and heterospecific behavioral antagonists in a wild songbird

The recognition of and differential responses to salient stimuli are among the main drivers of behavioral plasticity, yet, how animals evolve and modulate functional responses to novel classes of antagonistic stimuli remain poorly understood. We studied free-living male red-winged blackbirds (Agelaius phoeniceus) to test whether gene expression responses in blood are distinct or shared between patterns of aggressive behavioral responses directed at simulated conspecific versus heterospecific intruders. In this species, males defend territories against conspecific males and respond aggressively to female brown-headed cowbirds (Molothrus ater), a brood parasite that commonly lays eggs in blackbird nests. Both conspecific songs and parasitic calls elicited aggressive responses from focal subjects and caused a downregulation in genes associated with immune system response, relative to control calls of a second, harmless heterospecific species. In turn, only the conspecific song treatment elicited an increase in singing behavior and an upregulation of genes associated with metabolic processes relative to the two heterospecific calls. Our results suggest that aspects of antagonistic responses to both conspecifics and brood parasites can be based on similar physiological responses, suggestive of shared molecular and behavioral pathways involved in the recognition and reaction to both evolutionarily old and new enemies.

animal behavior and cognition↗

Evolutionary dynamics of recent selection for enhanced social cognition

Cognitive abilities can vary dramatically among species though little is known about the dynamics of cognitive evolution. Here we demonstrate that recent evolution of visual individual recognition in the paper wasp Polistes fuscatus is the target of arguably the strongest positive selective pressure in the species recent history. The most extreme selective sweeps in P. fuscatus are associated with genes known to be involved in long-term memory formation, mushroom body development and visual processing - all traits that have recently evolved in association with individual recognition. Cognitive evolution appears to have been driven initially by selection on standing variation in perceptual traits followed by both hard and soft sweeps on learning and memory. Evolutionary modeling reveals that intense selection as observed in P. fuscatus is likely the norm during the early stages of cognitive evolution. These data provide insight into the dynamics of cognition evolution demonstrating that social selection for increased intelligence can lead to rapid multi-genic adaptation of enhanced recognition abilities.

animal behavior and cognition↗