Biology subjects

Moreyra, N. N.

Publications and source records attributed to Moreyra, N. N..

3 recordsLinked to original sources

bioRxiv2026

Contemporary ecological heterogeneity shapes candidate adaptive genomic variation across the native range of an invasive herbivore

Ecological heterogeneity within a species native range can shape genomic variation available for subsequent range expansion and biological invasion. The cactus moth, Cactoblastis cactorum, is a South American oligophagous herbivore on Opuntia that has become an invasive pest outside its native range. In Argentina, populations span wide climatic and geographic gradients and exploit both native Opuntia species and the introduced crop O. ficus-indica. Using ddRADseq data from 136 individuals across 28 populations, we combined genome-wide differentiation scans (XtX), a host-use contrast, and genotype-environment association (GEA) analyses to identify candidate genomic signatures associated with contemporary ecological variation. XtX analyses detected 12 candidate regions, whereas the host-use contrast identified 17 regions differentiating populations sampled from O. ficus-indica and native Opuntia, several of which persisted in a geographically restricted sensitivity analysis. GEA analyses identified 167 covariate-specific loci, including candidate genes associated with detoxification and metabolism (CYP6B2), oxygen-sensing pathways (Egln1), and circadian regulation (TIMELESS). Convergence among analyses was limited but stronger than expected by chance. Temperature-associated loci in fax and Bag6 occurred within an XtX candidate region, whereas Hspg2 was independently recovered in host-use and environmental analyses and retained after geographic restriction. Most candidate variants occurred in non-coding genomic contexts, protein-altering variants were uncommon, and candidate genes spanned diverse functions, consistent with a potentially regulatory and polygenic architecture of adaptation. Overall, our results reveal a heterogeneous genomic landscape associated with climatic variation and introduced-host use, with recurrent loci providing the strongest evidence for localized adaptive differentiation across the native range of C. cactorum.

evolutionary biology↗

bioRxiv2022

Phylogenomics provides insights into the evolution of cactophily and host plant shifts in Drosophila

Cactophilic species of the Drosophila buzzatii cluster (repleta group) comprise an excellent model group to investigate genomic changes underlying adaptation to extreme climate conditions and host plants. In particular, these species offer a subject to study the transition from chemically simpler breeding sites (like prickly pears of the genus Opuntia) to chemically more complex hosts (columnar cacti). Here, we report four highly contiguous genome assemblies of three species of the buzzatii cluster. Based on this genomic data and inferred phylogenetic relationships, we identified candidate taxonomically restricted genes (TRGs) likely involved in the evolution of cactophily and cactus host specialization in internal branches of the subgenus Drosophila. Functional enrichment analyses of TRGs within the buzzatii cluster identified genes involved in detoxification, water preservation, immune system response, anatomical structure development, and morphogenesis. In contrast, processes that regulate responses to stress, as well as the metabolism of nitrogen compounds, transport, and secretion were found in the set of species that are columnar cacti dwellers. These findings are in line with the hypothesis that those genomic innovations brought about instrumental mechanisms underlying adaptation in a group of species that speciated in the arid regions of South America.

evolutionary biology↗

bioRxiv2019

What does mitogenomics tell us about the evolutionary history of the Drosophila buzzatii cluster (repleta group)

The Drosophila repleta group is an array of more than 100 cactophilic species endemic to the \"New World\". The acquisition of the ability to utilize decaying cactus tissues as breeding and feeding sites is a key aspect that allowed the successful diversification of the repleta group in the American deserts. Within this group, the Drosophila buzzatii cluster is a South American clade of seven cactophilic closely related species in different stages of divergence, a feature that makes it a valuable model system for evolutionary research. However, even though substantial effort has been devoted to elucidating the phylogenetic relationships among members of the D. buzzatii cluster, the issue is still controversial. In effect, molecular phylogenetic studies performed to date generated ambiguous results since tree topologies depend on the kind of molecular marker employed. Curiously, even though mitochondrial DNA has become a popular marker in evolutionary biology and population genetics, none of the more than twenty Drosophila mitogenomes assembled so far belongs to this cluster. In this work we report the assembly of six complete mitogenomes of five species: D. antonietae, D. borborema, D. buzzatii, D. seriema and two strains of D. koepferae, with the aim to revisit the phylogenetic relationships and divergence times by means of a mitogenomic approach. The recovered topology using complete mitogenomes gives support to the hypothesis of the monophyly of that the D. buzzatii cluster and shows two main clades, one including D. buzzatii and D. koepferae (both strains) and the other the remaining species. These results are in agreement with previous reports based on a few mitochondrial and/or nuclear genes but in conflict with the results of a recent large-scale nuclear phylogeny, suggesting that nuclear and mitochondrial genomes depict different evolutionary histories.

evolutionary biology↗