Melanie N. Brien's research while affiliated with The University of Sheffield and other places

Publications (11)

Article
Full-text available
Structural colours, produced by the reflection of light from ultrastructures, have evolved multiple times in butterflies. Unlike pigmentary colours and patterns, little is known about the genetic basis of these colours. Reflective structures on wing-scale ridges are responsible for iridescent structural colour in many butterflies, including the Mül...
Preprint
Full-text available
Colour is often used as an aposematic warning signal, with predator learning expected to lead to a single colour pattern within a population. However, there are many puzzling cases where aposematic signals are also polymorphic. The wood tiger moth, Arctia plantaginis , uses bright hindwing colours as a signal of unpalatability, and males have discr...
Article
Structural colours, produced by the reflection of light from ultrastructures, have evolved multiple times in butterflies. Unlike pigmentary colours and patterns, little is known about the genetic basis of these colours. Reflective structures on wing-scale ridges are responsible for iridescent structural colour in many butterflies, including the Mul...
Preprint
Full-text available
Structural colours, produced by the reflection of light from ultrastructures, have evolved multiple times in butterflies. Unlike pigmentary colours and patterns, little is known about the genetic basis of these colours. Reflective structures on wing-scale ridges are responsible for iridescent structural colour in many butterflies, including the Mül...
Article
Full-text available
Mimetic systems allow us to address the question of whether the same genes control similar phenotypes in different species. Although widespread parallels have been found for major effect loci, much less is known about genes that control quantitative trait variation. In this study, we identify and compare the loci that control subtle changes in the...
Preprint
Full-text available
Mimetic systems allow us to address the question of whether the same genes control similar phenotypes in different species. Although widespread parallels have been found for major effect loci, much less is known about genes that control quantitative trait variation. In this study, we identify and compare the loci that control subtle changes in the...
Article
Bright, highly reflective iridescent colours can be seen across nature and are produced by the scattering of light from nanostructures. Heliconius butterflies have been widely studied for their diversity and mimicry of wing colour patterns. Despite iridescence evolving multiple times in this genus, little is known about the genetic basis of the col...
Article
Full-text available
Iridescence is an optical phenomenon whereby colour changes with the illumination and viewing angle. It can be produced by thin film interference or diffraction. Iridescent optical structures are fairly common in nature, but relatively little is known about their production or evolution. Here we describe the structures responsible for producing blu...

Citations

... For example, QTL mapping and GWAS have identified many candidate loci associated with phenotypic variation and reproductive isolation in natural populations (e.g. Brien et al. [85], Gloss et al. [86] and Peter et al. [87] in this issue). Although large-scale GWAS enables the investigation of the genetic architecture at a far higher resolution than quantitative trait loci (QTL) mapping [69,86,87], linkage disequilibrium within a causative locus often precludes us from pinpointing causative genes and mutations solely by GWAS. ...
... The wood tiger moth (Arctia plantaginis) represents a compelling study species to investigate how different selective pressures can act on a single color locus and maintain within-population trait variation. In this system, male hindwing coloration is determined by a simple genetic basis (Suomalainen 1938;Nokelainen et al., 2022b;Brien et al., 2022): a one locustwo allele polymorphism (dominant W allele and recessive y allele), which translates into white (genotype: WW, Wy) and yellow (genotype: yy) males. Because this is an aposematic moth species, the color trait is not only used for intraspecific communication (i.e., sexual selection) but also to advertise their unpalatability to predators (i.e., interspecific communication). ...
... This leads to an exponential distribution of allele effect sizes, with few loci of relatively large effect and many of relatively small-effect (Dittmar et al., 2016;Orr, 1998). While this model may be applicable to some species (Bainbridge et al., 2020;McKay et al., 2008), we must take into account the effects of gene flow before we can confidently apply it to common ragweed. In contrast to this exponential distribution of allele effect sizes expected under adaptation to a single optimum without migration (Orr, 2005), divergent selection with migration is predicted to result in genetic architectures with fewer, larger, and more tightly linked alleles (i.e., oligogenic architecture) (Ferris et al., 2017;Tigano & Friesen, 2016;Yeaman & Otto, 2011). ...
... ;https://doi.org/10.1101https://doi.org/10. /2020 We found a strong association with wing shape variation in H. erato at the optix locus, which controls most of the red colour patterning (Bainbridge et al., 2020;Lewis et al., 2019;Meier et al., 2020;Van Belleghem et al., 2017). In Heliconius, wing shape has been traditionally studied in the context of mimicry, as similar wing shapes could aid locomotor mimicry (Mérot, Le Poul, Théry, & Joron, 2016;Srygley, 1994Srygley, , 1999. ...
... Heliconius also display structural colour, and in comparison to the well-studied pigmentary colours, very little is known about the development and genetic basis of these. While overall scale morphology is similar between iridescent and noniridescent scales in Heliconius, those with blue structural colour have overlapping ridge lamellae that act as multilayer reflectors (as in Morpho), along with a greater density of ridges on the scale (narrower ridge spacing) [16,23]. ...
... For example, a lamellar structure in the ridges forms multilayer reflectors that produce the iridescent (angle-dependent) blue in Morpho butterflies [13] and UV reflectance in Colias eurytheme [14,15]. The variations in hue and brightness of colour produced in the intricate structures of the upperscale surface depend on an interplay between the number of lamellae, the thickness of each layer and the spacing between the ridges [16]. ...