Biology subjects

Lopez Villavicencio, M.

Publications and source records attributed to Lopez Villavicencio, M..

3 recordsLinked to original sources

bioRxiv2025

Evolution of opsin genes in closely-related species of butterflies specialized in different microhabitats.

How do adaptive processes acting on the coevolution of opsin genes shape the evolution of colour vision in animals? At large phylogenetic scales, natural selection due to the contrasted light environments has been found to impact the evolution of photoreceptor genes. However, in closely-related species, species interactions due to sexual selection or competition may also influence opsin evolution. Here, we investigate the diversification of opsin sequences and their expression in closely-related blue Morpho butterfly species, living in different vertical strata within tropical forests, to shed light on the biotic and abiotic selective pressures shaping the coordinated evolution of opsin genes. We combined comparative genomics, transcriptomics, and immunochemistry to characterize the expression and the spatial distribution of the opsin proteins found in the eyes of Morpho helenor. We detected a double duplication of the LW opsin and found unique ommatidial types compared to other butterfly species. We then investigated the evolution of opsin genes among 21 Morpho species, found signatures of positive selection on two opsin genes (LW3Rh and BRh), and identified key co-evolving amino-acids within and among these two opsin genes. We showed that such opsin evolution was correlated with both light environment and wing coloration, highlighting the joint effect of several selective pressures in the coordinated evolution of proteins.

evolutionary biology↗

bioRxiv2024

Increased evolutionary rate in the Z-chromosome of Morpho butterflies and implications for speciation.

The evolution of reproductive isolation between populations shapes divergence in genome structure and content: comparing the genomes of closely-related species can thus enlighten the speciation process. Comparisons of genomes of allopatric vs. sympatric species sharing similar vs. dissimilar ecological niches allows to specifically investigate the effect of reinforcement and ecological specialization on genome evolution. In the butterfly genus Morpho, several species can be found in sympatry presenting specialisation in different microhabitats and temporal niches. Here, we sequenced, assembled and annotated the genomes of 8 Morpho species and used previously published genomes of three other Morpho species to study genomic rearrangements and signatures of positive selection. We found extensive chromosomal rearrangements in the Z chromosome compared to the autosomes, particularly among closely related sympatric species occupying similar niches, pointing at the putative role of inversions in preventing gene flow at a postzygotic level. We also detected a higher proportion of genes under positive selection on the Z-chromosome compared to the autosomes, suggesting a potential role of the Z-chromosome in driving adaptive evolution in Morpho. Finally, because of the divergence in daily activities between species, we studied the evolution of eight genes involved in the circadian clock and detected a signature of positive selection on the gene Period, located in the Z chromosome. By studying the evolution of genome structure and coding sequences, our study indicates fast evolution of the Z-chromosome, partly driven by selection, throughout this genus, highlighting the putative implication of this sexual chromosome on pre and post-zygotic isolation.

evolutionary biology↗

bioRxiv2022

Genome assembly of three Amazonian Morpho butterflyspecies reveals Z-chromosome rearrangements betweenclosely-related species living in sympatry

The genomic processes enabling speciation and the coexistence of species in sympatry are still largely unknown. Here we describe the whole genome sequencing and assembly of three closely-related species from the butterfly genus Morpho: Morpho achilles (Linnaeus, 1758), M. helenor (Cramer, 1776) and M. deidamia (Hubner, 1819). These large blue butterflies are emblematic species of the Amazonian rainforest. They live in sympatry in a wide range of their geographical distribution and display parallel diversification of dorsal wing colour pattern, suggesting local mimicry. By sequencing, assembling and annotating their genomes, we aim at uncovering pre-zygotic barriers preventing gene flow between these sympatric species. We found a genome size of 480 Mb for the three species and a chromosomal number ranging from 2n = 54 for M. deidamia to 2n = 56 for M. achilles and M. helenor. We also detected inversions on the sex chromosome Z that were differentially fixed between species, suggesting that chromosomal rearrangements may contribute to their reproductive isolation. The annotation of their genomes allowed us to recover in each species at least 12,000 protein-coding genes and to discover duplications of genes potentially involved in pre-zygotic isolation like genes controlling colour discrimination (L-opsin). Altogether, the assembly and the annotation of these three new reference genomes open new research avenues into the genomic architecture of speciation and reinforcement in sympatry, establishing Morpho butterflies as a new eco-evolutionary model.

genomics↗