Biology subjects

Aguilar, J. M.

Publications and source records attributed to Aguilar, J. M..

5 recordsLinked to original sources

bioRxiv2024

Modality specific memory enhancement in Heliconius butterflies

How animals perceive, process and respond to environmental cues is tightly tuned to the species-specific demands, and reflected by the structure of neural systems. In the Neotropical butterflies, Heliconius, the mushroom bodies, insect learning and memory centres, are significantly expanded compared to their closest relatives. This expansion coincided with the evolution of a novel diet, pollen feeding, and a spatial foraging behaviour consistent with trap-lining. Previous research has shown that Heliconius have more accurate visual long-term memory than other Heliconiini. Here, we tested whether this enhanced memory stability is specific to visual cues by conducting a long-term olfactory memory assay in two Heliconius species and two outgroup species. We found no differences in the long-term olfactory memory between Heliconius species and the outgroup species. Combining data from olfactory and visual memory trials confirms a significant shift in performance among sensory modalities between Heliconius and outgroup genera. In contrast, tests of how Heliconiini prioritise olfactory and visual cues when in presented in conflict also show no consistent shift in attentiveness to sensory cues between species. Our data provide a rare case where memory performance has been compared across species and sensory modalities, to identify evidence of a modality specific shift.

animal behavior and cognition↗

bioRxiv2023

Evolution of chemosensory and detoxification gene families across herbivorous Drosophilidae

Herbivorous insects are exceptionally diverse, accounting for a quarter of all known eukaryotic species, but the genetic basis of adaptations that enabled this dietary transition remains poorly understood. Many studies have suggested that expansions and contractions of chemosensory and detoxification gene families - genes directly mediating interactions with plant chemical defenses - underlie successful plant colonization. However, this hypothesis has been challenging to test because the origins of herbivory in many lineages are ancient (>150 million years ago [mya]), obscuring genomic evolutionary patterns. Here, we characterized chemosensory and detoxification gene family evolution across Scaptomyza, a genus nested within Drosophila that includes a recently derived (<15 mya) herbivore lineage of mustard (Brassicales) specialists and carnation (Caryophyllaceae) specialists, and several non-herbivorous species. Comparative genomic analyses revealed that herbivorous Scaptomyza have among the smallest chemosensory and detoxification gene repertoires across 12 drosophilid species surveyed. Rates of gene turnover averaged across the herbivore clade were significantly higher than background rates in over half of the surveyed gene families. However, gene turnover was more limited along the ancestral herbivore branch, with only gustatory receptors and odorant binding proteins experiencing strong losses. The genes most significantly impacted by gene loss, duplication, or changes in selective constraint were those involved in detecting compounds associated with feeding on plants (bitter or electrophilic phytotoxins) or their ancestral diet (yeast and fruit volatiles). These results provide insight into the molecular and evolutionary mechanisms of plant-feeding adaptations and highlight strong gene candidates that have also been linked to other dietary transitions in Drosophila.

evolutionary biology↗

bioRxiv2022

Insights into the evolution of herbivory from a leaf-mining, drosophilid fly

Herbivorous insects and their host plants comprise most known species on Earth. Illuminating how herbivory repeatedly evolved in insects from non-herbivorous lineages is critical to understanding how this biodiversity is created and maintained. We characterized the trophic niche of Scaptomyza flava, a representative of a lineage nested within the Drosophila that transitioned to herbivory [~]15 million years ago. We used natural history studies to determine if S. flava is a true herbivore or a cryptic microbe-feeder. Specifically, we quantified oviposition substrate choice and larval viability across food-types, trophic-related morphological traits, and nitrogen isotope and sterol profiles across putatively herbivorous and non-herbivorous drosophilids. We confirmed that S. flava is an obligate herbivore of living plants. Paired with its genetic model host, Arabidopsis thaliana, S. flava is a novel and powerful system for exploring mechanisms underlying the evolution of herbivory, a complex trait that enabled the exceptional diversification of insects.

ecology↗

bioRxiv2022

Plant species within Streptanthoid Complex associate with distinct microbial communities that shift to be more similar under drought

Prolonged water stress can reduce plant growth and fitness and may shift rhizoplane microbial communities. Although drought affects microbial structure of many plant species, it is still poorly understood whether closely related plant species host distinct microbial communities or respond similarly to drought. To explore this question, eight members of the Streptanthus clade with varying affinity to serpentine were subjected to three watering regimes. Rhizoplane bacterial communities were described using 16S rRNA gene amplicon sequencing and we explored the impact of watering treatment and plant species on alpha diversity, differential abundance, and beta diversity of soil bacterial communities. Among most plant species, reduced watering also reduced alpha diversity, but plant species did not strongly impact alpha diversity. Drought treatment reduced microbial community dissimilarity among samples: bacterial communities were more similar when plants received less water. Watering altered the relative abundance of bacterial genera within Proteobacteria, Firmicutes, Bacteroidetes, Planctomycetes, and Acidobacteria, which responded similarly in the rhizoplane of most plant species. These results suggest that prolonged water stress in Streptanthus spp. can result in convergent microbial communities among plant species. We suggest the functional consequences of these shifts be examined to assess effects on plant and microbial fitness under drought conditions.

genomics↗

bioRxiv2020

Highly contiguous assemblies of 101 drosophilid genomes

Over 100 years of studies in Drosophila melanogaster and related species in the genus Drosophila have facilitated key discoveries in genetics, genomics, and evolution. While high-quality genome assemblies exist for several species in this group, they only encompass a small fraction of the genus. Recent advances in long read sequencing allow high quality genome assemblies for tens or even hundreds of species to be generated. Here, we utilize Oxford Nanopore sequencing to build an open community resource of high-quality assemblies for 101 lines of 95 drosophilid species encompassing 14 species groups and 35 sub-groups with an average contig N50 of 10.5 Mb and greater than 97% BUSCO completeness in 97/101 assemblies. These assemblies, along with detailed wet lab protocol and assembly pipelines, are released as a public resource and will serve as a starting point for addressing broad questions of genetics, ecology, and evolution within this key group.

evolutionary biology↗