The European Map Butterfly Araschnia levana as a Model to Study the Molecular Basis and Evolutionary Ecology of Seasonal Polyphenism

Abstract

The European map butterfly Araschnia levana is a well-known example of seasonal polyphenism. Spring and summer imagoes exhibit distinct morphological phenotypes. Key environmental factors responsible for the expression of different morphs are day length and temperature. Larval exposure to light for more than 16 h per day entails direct development and results in the adult f. prorsa summer phenotype. Less than 15.5 h per day increasingly promotes diapause and the adult f. levana spring phenotype. The phenotype depends on the timing of the release of 20-hydroxyecdysone in pupae. Release within the first days after pupation potentially inhibits the default “levana-gene-expression-profile” because pre-pupae destined for diapause or subitaneous development have unique transcriptomic programs. Moreover, multiple microRNAs and their targets are differentially regulated during the larval and pupal stages, and candidates for diapause maintenance, duration, and phenotype determination have been identified. However, the complete pathway from photoreception to timekeeping and diapause or subitaneous development remains unclear. Beside the wing polyphenism, the hormonal and epigenetic modifications of the two phenotypes also include differences in biomechanical design and immunocompetence. Here, we discuss research on the physiological and molecular basis of polyphenism in A. levana, including hormonal control, epigenetic regulation, and the effect of ecological parameters on developmental fate.

Insights Into Chemosensory Proteins From Non-Model Insects: Advances and Perspectives in the Context of Pest Management

“…Nevertheless, it can be a model insect due to its ease of rearing and use as hosts for the study of pathogens ( Killiny, 2018 ; Ménard et al, 2021 ). Another example is the butterfly Araschnia levana , which can be considered a model for the study of the molecular basis and evolutionary ecology of seasonal polyphenism due to its characteristic seasonal dimorphism ( Baudach and Vilcinskas, 2021 ). In recent years, the order Coleoptera has taken on great importance in the identification of little-known species, which can be considered models for their particularities.…”

Neuropeptide Bursicon and its receptor mediated the transition from summer-form to winter-form ofCacopsylla chinensis

“…Nature presents us with numerous remarkable examples of polyphenism. For instance, we observe seasonal polyphenism in psylla (Butt and Stuart, 1986) and butterflies (Emily et al, 2014; Baudach and Vilcinskas, 2021), sexual and wing polyphenism in aphids and planthoppers (Xu et al, 2015; Shang et al, 2020), caste polyphenism in ants and honeybees (Kucharski et al, 2008; Bonasio et al, 2012), sex determination in reptiles and fish regulated by temperature and social factors (Janzen and Phillips, 2006; Liu et al, 2017), and environmentally induced polyphenism in plants (Gratani, 2014). Undoubtedly, polyphenism plays a major contributor to the population dynamics of insects worldwide (Noor et al, 2008).…”

Larval growth rate affects wing shape more than eyespot size in the seasonally polyphenic butterflyMelanitis leda

“…Moreover, species can use more than one cue, and these cues may interact with each other (Yoon et al 2023). Parts of the physiological cascade that translates environmental cues into induction of the phenotype are well understood in some insect model organisms (Baudach & Vilcinskas 2021; Monteiro 2017; Oostra et al 2011; Singh et al 2020; Steward et al 2022). However, we have limited insight into how multiple cues are integrated, and induce the expression of a suite of traits, especially in non-model organisms.…”