Biology subjects

Buerkle, N. P.

Publications and source records attributed to Buerkle, N. P..

3 recordsLinked to original sources

bioRxiv2022

Genetic and peripheral visual system changes underlie evolving butterfly mate preference

Many studies have linked genetic variation to behavior, but less is known about how that variation alters the neural circuits that drive behavior. We investigated the genetic and neurobiological basis of courtship preference variation in Heliconius butterflies, which use vision to identify appropriate mates based on wing color patterns. We found that Heliconius cydno preference variation was strongly associated with genetic variation and differential expression of senseless-2, a gene predominantly expressed in the eye. Further measurements of photoreceptor sensitivities revealed differences in inter-photoreceptor inhibition of ultraviolet-sensitive cells corresponding to courtship preference variation. Our results reveal a genetic basis for preference/cue co-evolution, suggest a link between sens-2 and visual system variation, and support the idea that changing peripheral neural computations can significantly alter essential behaviors. SummaryGenetic and expression variation of senseless-2 and inter-photoreceptor inhibition predict visual mate preference in a clade of diverse butterflies.

evolutionary biology↗

bioRxiv2022

Sex-limited diversification of the eye in Heliconius butterflies

Butterflies have evolved an immense diversity in eye organization to support a range of vision-based behaviors including courtship, oviposition, and foraging. This diversity has been surveyed extensively across the butterfly phylogeny, and here we take a complementary approach to characterize the eye within a group of closely related Heliconius butterflies. Using a combination of immunostaining for different opsins and eyeshine for determining the distribution of light-filtering screening pigments, we identified several sexually dimorphic features of eye organization where male eyes varied and female eyes did not. Ultraviolet (UV) sensitive photoreceptors varied in which of two UV opsins were expressed, including co-expression of both within single photoreceptors, and these differences were consistent with a role in courtship and conspecific identification. Additional differences across species and sex included the distribution of three ommatidial types defined by the expression pattern of UV and blue opsins, the distribution of a red screening pigment, and which ommatidial types expressed the red screening pigment. We hypothesize that female eyes are optimized for a dimorphic behavior such as oviposition, while male eyes adapt to other selective pressures such as the local light environment.

neuroscience↗

bioRxiv2019

Ancestral neural computations constrain the evolution of novel computations in simulated color vision networks

Efficient coding has been a successful organizational principle in neuroscience, but a more general theoretical framework needs to include the capacity for biological constraints to impede the realization of optimal circuit design. Here, we explore how evolution shapes the computational organization of a circuit using color vision as a model system. Taking a theoretical, machine learning approach allowed us to simulate the evolution of tetrachromatic color vision from a trichromatic ancestor both within and across distinct phylogenetic lineages. Analyzing network performance showed that trichromatic starting weights impose a significant constraint on learning rate, although the incremental increase in input layer complexity leads to better overall performance. Analyzing hidden layer computations showed that ancestry severely constrained evolution into a restricted and predictable portion of the theoretically available computational state space. Overall, our simulations of color vision evolution suggest that phylogenetic history is an important aspect of the functional organization of neural circuits.

neuroscience↗