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Ernst, D. A.

Publications and source records attributed to Ernst, D. A..

3 recordsLinked to original sources

A learning experience elicits sex-dependent neurogenomic responses in Bicyclus anynana butterflies

Sexually dimorphic behavior is pervasive across animals, with males and females exhibiting different mate selection, parental care, foraging, dispersal, and territorial strategies. However, the genetic underpinnings of sexually dimorphic behaviors are poorly understood. Here we investigate gene networks and expression patterns associated with sexually dimorphic imprinting-like learning in the butterfly Bicyclus anynana. In this species, both males and females learn visual preferences, but learn preferences for different traits and use different signals as salient, unconditioned cues. To identify genes and gene networks associated with this behavior, we examined gene expression profiles of the brains and eyes of male and female butterflies immediately post training and compared them to the same tissues of naive individuals. We found more differentially expressed genes and a greater number of significant gene networks in the eye, indicating a role of the peripheral nervous system in visual imprinting-like learning. Females had higher chemoreceptor expression levels than males, supporting the hypothesized sexual dimorphic use of chemical cues during the learning process. In addition, genes that influence B. anynana wing patterns (sexual ornaments), such as invected, spalt, and apterous, were also differentially expressed in the brain and eye, suggesting that these genes may influence both sexual ornaments and the preferences for these ornaments. Our results indicate dynamic and sex-specific responses to social scenario in both the peripheral and central nervous systems and highlight the potential role of wing patterning genes in mate preference and learning across the Lepidoptera.

animal behavior and cognition↗

Ontogenetic changes in sensory gene expression in Bicyclus anynana butterflies

Animal behavior is largely driven by the information that animals are able to extract and process from their environment. However, the function and organization of sensory systems often change throughout ontogeny, particularly in animals that undergo indirect development. As an initial step toward investigating these ontogenetic changes at the molecular level, we characterized the sensory gene repertoire and examined the expression profiles of genes linked to vision and chemosensation in two life stages of an insect that undertakes a dramatic metamorphosis, the butterfly Bicyclus anynana. Using RNA-seq, we compared gene expression in the heads of late fifth instar larvae and newly-eclosed adults that were reared under identical conditions. Over 50% of all expressed genes were differentially expressed between the two developmental stages, with 4,046 genes upregulated in larval heads and 4,402 genes upregulated in adult heads. In larvae, upregulated vision-related genes were biased toward those involved with eye development, while phototransduction genes dominated the vision genes that were upregulated in adults. Moreover, the majority of the chemosensory genes we identified in the B. anynana genome were differentially expressed between larvae and adults, several of which share homology with genes linked to pheromone detection, host plant recognition, and foraging in other species of Lepidoptera. These results reveal promising candidates for furthering our understanding of sensory processing and behavior in the disparate developmental stages of butterflies and other animals that undergo metamorphosis.

genomics↗

Wing-pattern-specific effects of experience on mating behavior in Heliconius melpomene butterflies

Many animals have the ability to learn, and some taxa have shown learned mate preference. This learning may be important for speciation in some species. The butterfly Heliconius melpomene is a model system for several areas of research, including hybridization, mate selection, and speciation, partially due to its widespread diversity of wing patterns. It remains unclear whether these butterflies can learn to prefer certain mates and if social experience shapes realized mating preferences. Here we test whether previous experience with a female influences male mate preference for two different H. melpomene subspecies, H. m. malleti and H. m. rosina. We conducted no-choice behavioral assays to determine if latency to court and whether males courted (vs no courtship) differed between naive males and males with previous exposure to a young, sexually mature, virgin female. To test whether assortative courtship preference is learned in H. melpomene, males were either paired with a female who shared their phenotype or one who did not. Naive H. m. malletti males courted assortatively, while naive H.m. rosina males did not. Experienced H. m. malleti males reduced their courting relative to naive males, suggesting that social experience with a sexually mature female that does not result in copulation may be perceived as a negative experience. In contrast, experienced H. m. rosina males exhibited similar courting rates to naive H. m. rosina males. Our results suggest that social experience can influence male mating behavior in H. melpomene and that behavioral plasticity may differ across populations in this species.

animal behavior and cognition↗