Dataset Information

The fitness effects of a pale mutant in the aposematic seed bug Lygaeus simulans indicate pleiotropy between warning coloration and life history.

ABSTRACT: Conspicuous warning colors that signal chemical or other defenses are common in the natural world. For instance, such aposematic warning patterns of red-and-black or yellow-and-black are common among insect taxa, particularly in the order Hemiptera, often forming the basis of Batesian and/or Müllerian mimicry rings. In addition, it has been repeatedly noted that color polymorphisms or mutants that influence pigmentation can show pleiotropy with other behavioral, physiological, or life-history traits. Here, we describe a pale mutant of the seed bug Lygaeus simulans that appeared in our laboratory population in 2012, which differs in color to the wild-type bugs. Through multigenerational experimental crosses between wild-type and pale mutant L. simulans, we first show that the pale phenotype segregates as a single Mendelian locus, with the pale allele being recessive to the wild type. Next, we show (a) that there is a large heterozygous advantage in terms of fecundity, (b) that pale females suffer reduced longevity, and (c) that pale males have increased body length compared to wild-type homozygotes. Our data therefore suggest that the color locus is pleiotropic with a number of life-history traits, opening the door for a more complete genetic analysis of aposematic coloration in this species. In addition, this phenotype will be useful as a visible genetic marker, providing a tool for investigating sperm competition and other post-copulatory drivers of sexual selection in this species.

SUBMITTER: Balfour VL

PROVIDER: S-EPMC6308859 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The fitness effects of a pale mutant in the aposematic seed bug <i>Lygaeus simulans</i> indicate pleiotropy between warning coloration and life history.

Balfour Vicki L VL Aumont Cédric C Dougherty Liam R LR Shuker David M DM

Ecology and evolution 20181204 24

Conspicuous warning colors that signal chemical or other defenses are common in the natural world. For instance, such aposematic warning patterns of red-and-black or yellow-and-black are common among insect taxa, particularly in the order Hemiptera, often forming the basis of Batesian and/or Müllerian mimicry rings. In addition, it has been repeatedly noted that color polymorphisms or mutants that influence pigmentation can show pleiotropy with other behavioral, physiological, or life-history tr ...[more]

PMID: 30619588

Similar Datasets

Project description:Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency-dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in the same population. Recent research has yielded an increased awareness of this diversity, challenging the paradigm of signal monomorphy in aposematic animals. Here we provide a comprehensive synthesis of these disparate lines of investigation, identifying within them three broad classes of explanation for variation in aposematic warning signals: genetic mechanisms, differences among predators and predator behaviour, and alternative selection pressures upon the signal. The mechanisms producing warning coloration are also important. Detailed studies of the genetic basis of warning signals in some species, most notably Heliconius butterflies, are beginning to shed light on the genetic architecture facilitating or limiting key processes such as the evolution and maintenance of polymorphisms, hybridisation, and speciation. Work on predator behaviour is changing our perception of the predator community as a single homogenous selective agent, emphasising the dynamic nature of predator-prey interactions. Predator variability in a range of factors (e.g. perceptual abilities, tolerance to chemical defences, and individual motivation), suggests that the role of predators is more complicated than previously appreciated. With complex selection regimes at work, polytypisms and polymorphisms may even occur in Müllerian mimicry systems. Meanwhile, phenotypes are often multifunctional, and thus subject to additional biotic and abiotic selection pressures. Some of these selective pressures, primarily sexual selection and thermoregulation, have received considerable attention, while others, such as disease risk and parental effects, offer promising avenues to explore. As well as reviewing the existing evidence from both empirical studies and theoretical modelling, we highlight hypotheses that could benefit from further investigation in aposematic species. Finally by collating known instances of variation in warning signals, we provide a valuable resource for understanding the taxonomic spread of diversity in aposematic signalling and with which to direct future research. A greater appreciation of the extent of variation in aposematic species, and of the selective pressures and constraints which contribute to this once-paradoxical phenomenon, yields a new perspective for the field of aposematic signalling.

Project description:Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological factors.

Dataset Information

The fitness effects of a pale mutant in the aposematic seed bug Lygaeus simulans indicate pleiotropy between warning coloration and life history.

Publications

The fitness effects of a pale mutant in the aposematic seed bug <i>Lygaeus simulans</i> indicate pleiotropy between warning coloration and life history.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets