Biology subjects

Pinheiro de Castro, E. C.

Publications and source records attributed to Pinheiro de Castro, E. C..

4 recordsLinked to original sources

bioRxiv2025

Gene loss associated with plasticity-first evolution in Heliconius butterflies

Phenotypic plasticity occurs when a genotype can produce more than one phenotype under different environmental conditions. Genetic accommodation allows plastic phenotypes to be tuned to new environments and eventually to even be lost. The colourful and toxic Heliconiini butterflies have biochemical plasticity - they either sequester their cyanogenic glucosides (CG) from their larval hostplant or biosynthesize them when compounds for sequestration are not available. Here, we trace the evolution of CG biosynthesis in Heliconiini butterflies, a fundamental component of this biochemical plasticity. We first reconstructed the evolutionary history of biochemical plasticity in Heliconiini butterflies using chemical data from over 700 individuals, demonstrating that plasticity was ancestral in the tribe and further lost in a few clades, such as the Sapho clade that only sequester CGs. In lepidopterans, CG biosynthesis has been fully characterized in the moth Zygaena filipendulae, and is composed of CYP405A2, CYP332A3, and UGT33A1. Thus, we CRISPR-edited the gene CYP405 in Heliconius erato, and confirmed that CYP405-knockout caterpillars do not biosynthesize CGs. We identified the CYP405s and CYP332s in other lepidopterans and found that both genes were independently co-opted into CG biosynthesis in the Heliconiinae butterflies and Zygaena moths. Most lepidopterans have a CYP332, but CYP405 is mostly restricted to butterflies and has been duplicated in all Heliconius species. Although several CYP405 copies were found in the Sapho clade, they lack structurally important P450 domains, which explain they loss of biochemical plasticity via specialization in CG sequestration. Our findings represent one of the few examples of plasticity-first evolution in which the genetic mechanisms associated with its accommodation/assimilation are known.

evolutionary biology↗

bioRxiv2023

Pollen-feeding delays reproductive senescence and maintains toxicity of Heliconius butterflies

Dietary shifts may act to ease energetic constraints and allow organisms to optimise life-history traits. Heliconius butterflies differ from other nectar-feeders due to their unique ability to digest pollen, which provides a reliable source of amino acids to adults. Pollen-feeding has been associated with prolonged adult lifespan and increased fertility, yet there is a lack of empirical data demonstrating how pollen consumption influences key fitness traits, including chemical defences and adult body weight, as well as fertility over their elongated lifespan. Here, we investigated the effect of pollen-feeding on fertility, weight and chemical defences, as well as offspring defences, controlling for butterfly age and sex. Recently emerged Heliconius erato butterflies of similar size were fed for 14 or 45 days on one of three diets: sugar solution only, or sugar solution replenished with either amino acid supplement or pollen. At the end of the experiment, oviposition assays were performed to evaluate fertility, and afterwards all butterflies and eggs were weighed and used for quantification of cyanogenic glucosides (CG). We found that there is an age-specific and sex-specific effect of pollen-feeding on butterfly weight, with both the sugar-only and amino-acid supplement diets reducing the weight of old females (45d), but not young females (14d) or males of any age. Females fed only sugar significantly reduced their egg-laying through adulthood, whereas females that had access to pollen maintained their fertility. Diet had a significant effect on the maintenance of the chemical defence of females, but not males. Curiously, even though females that have access to pollen were heavier, more toxic and laid more eggs, this did not translate into improvements in offspring defences, as eggs from butterflies of all ages and diet treatments had similar CG content. Our results emphasise the importance of controlling for age-specific and sex-specific effects in studies of life-history evolution and demonstrate that dietary novelty can relax energetic constraints.

evolutionary biology↗

bioRxiv2022

Evolutionary dynamics of genome size and content during the adaptive radiation of Heliconiini butterflies

Heliconius butterflies, a speciose genus of Mullerian mimics, represent a classic example of an adaptive radiation that includes a range of derived dietary, life history, physiological and neural traits. However, key lineages within the genus, and across the broader Heliconiini tribe, lack genomic resources, limiting our understanding of how adaptive and neutral processes shaped genome evolution during their radiation. We have generated highly contiguous genome assemblies for nine new Heliconiini, 29 additional reference-assembled genomes, and improve 10 existing assemblies. Altogether, we provide a major new dataset of annotated genomes for a total of 63 species, including 58 species within the Heliconiini tribe. We use this extensive dataset to generate a robust and dated heliconiine phylogeny, describe major patterns of introgression, explore the evolution of genome architecture, and the genomic basis of key innovations in this enigmatic group, including an assessment of the evolution of putative regulatory regions at the Heliconius stem. Our work illustrates how the increased resolution provided by such dense genomic sampling improves our power to generate and test gene-phenotype hypotheses, and precisely characterize how genomes evolve.

evolutionary biology↗

bioRxiv2019

Sequestration and functional diversification of cyanogenic glucosides in the life cycle of Heliconius melpomene

Heliconius butterflies are highly specialized in Passiflora, laying eggs and feeding as larvae only on these plants. Interestingly, Heliconius butterflies and Passiflora plants both contain cyanogenic glucosides (CNglcs). While feeding on specific Passiflora species, Heliconius melpomene larvae are able to sequester simple cyclopentenyl CNglcs, the most common CNglcs in this plant genus. Yet, aromatic, aliphatic, and modified CNglcs have been reported in Passiflora species and they were never tested for sequestration by heliconiine larvae. As other cyanogenic lepidopterans, H. melpomene also biosynthesize the aliphatic CNglcs linamarin and lotaustralin, and their toxicity does not rely exclusively on sequestration. Although the genes encoding the enzymes in the CNglc biosynthesis have not yet been fully biochemically characterized in butterflies, the cytochromes P450 CYP405A4, CYP405A5, CYP405A6 and CYP332A1 are hypothesized to be involved in this pathway in H. melpomene. In this study, we determine how the CNglc composition and expression of the putative P450s involved in the biosynthesis of these compounds vary at different development stages of Heliconius butterflies. We also established which kind of CNglcs H. melpomene larvae can sequestered from Passiflora. By analysing the chemical composition of the haemolymph from larvae fed with different Passiflora diets, we observed that H. melpomene is able to sequestered prunasin, an aromatic CNglcs, from P. platyloba. They were also able to sequester amygdalin, gynocardin, [C13/C14]linamarin and [C13/C14]lotaustralin painted on the plant leaves. The CNglc tetraphyllin B-sulphate from P. caerulea was not detected in the larval haemolymph, suggesting that such modified CNglcs cannot be sequestered by Heliconius. Although pupae and virgin adults contain dihydrogynocardin resulting from larval sequestration, this compound was metabolized during adulthood, and not used as nuptial gift or transferred to the offspring. Thus, we speculate that dihydrogynocardin was catabolized to recycle nitrogen and glucose, and/or to produce fitness signals during courtship and calling. Mature adults had a higher concentration of CNglcs than any other developmental stages due to intense de novo biosynthesis of linamarin and lotaustralin. All CYP405As were expressed in adults, whereas larvae mostly expressed CYP405A4. Our results shed light on the importance of CNglcs in Heliconius biology and for their coevolution with Passiflora.

biochemistry↗