Biology subjects

Aguilar, P.

Publications and source records attributed to Aguilar, P..

5 recordsLinked to original sources

bioRxiv2026

Resolution of multi-receiver trade-offs in wall lizard colouration

Animal colouration evolves under multiple, often conflicting, selective pressures. Conspicuous, non-aposematic colour-patterns that enhance conspecific communication may simultaneously increase detectability by predators. Such trade-offs can be resolved by optimising colour-patterns to match the perceptual abilities of different receivers. We tested whether dorsal colour-patterns of the Lusitanian wall lizard (Podarcis lusitanicus) are optimised for ecologically relevant receivers across relevant viewing distances, while accounting for the visual acuity of conspecifics and predators. Conspecifics and snakes detected chromatic information at shorter distances, whereas achromatic and luminance information were detected at longer distances. Birds showed a uniform decline in detectability across the colour-pattern components with increasing viewing distance. Larger males retained high chromatic detectability across all receivers despite the general distance-related decline, whereas females and smaller individuals exhibited less salient colour patterns, consistent with predator avoidance strategy. Our results show that lizards resolve the trade-off between conspecific communication and predator detection through distance-dependent colour-pattern perceptibility across receivers. This resolution breaks down in large males, for whom the benefits of salient chromatic patterns for intraspecific communication may outweigh increased detectability to predators.

evolutionary biology↗

bioRxiv2025

Age-dependent gut microbiota dynamics and their association with male fitness traits in Drosophila melanogaster

Growing evidence suggests that the gut microbiota plays a key role in shaping life history in a wide range of species, including well-studied model organisms like Drosophila melanogaster. Although recent studies have explored the relationship between gut microbiota and female life history, the link between gut microbiota and male life history remains understudied. In this study, we explored the role of gut microbiota in shaping male life history traits by correlating variation in life history traits across genetically homogeneous isolines with their naturally occurring gut microbiota. Using 22 isolines from the Drosophila melanogaster Genetic Reference Panel (DGRP), we measured lifespan, early/late-life reproduction, and early/late-life physiological performance. We characterized the gut microbiota composition in young (5 days old) and old (26 days old) flies using 16S rDNA sequencing. We observed significant variation in male life history traits across isolines, as well as age-related changes in gut microbiota composition. Using machine learning, we showed that gut microbiota composition could predict the age of the organisms with high accuracy. Associations between gut microbiota and life history traits were notable, particularly involving the Acetobacter genus. In early life, the abundance of Acetobacter ascendens was associated with functional aging, while Acetobacter indonesiensis was linked to reproductive senescence. In late life, higher abundances of A. ascendens and Acetobacter pasteurianus were negatively associated with lifespan. These findings highlight the potential role of gut microbiota, especially the Acetobacter genus, in male fitness and aging.

microbiology↗

bioRxiv2024

Metazoan diversity in Chilean hypersaline lakes unveiled by environmental DNA

Saline and hypersaline wetlands are biodiversity hotspots for metazoans such as aquatic invertebrates and wading birds. However, the survival of these habitats and their biota is increasingly threatened by a combination of pressures from climate change and extractive processes, jeopardizing the long-term ecological functioning of these ecosystems. With the goal of improving conservation efforts through state-of-the-art survey techniques in hypersaline ecosystems, this study tests the use of environmental DNA (eDNA) methods for metazoan biomonitoring. We employed a multi-assay approach utilizing three genetic markers--12S rRNA, 18S rRNA, and COI --to analyze biodiversity in two types of environmental substrates, sediment and water. These samples were collected from three hypersaline lakes situated at high altitude in Northern Chile: Salar de Atacama (Laguna Puilar), Salar de Pujsa, and Salar de Tara. In addition, we compared the eDNA outputs with results generated from aquatic macroinvertebrate assessments using kick-nets to evaluate the potential for complementary sampling approaches. Our eDNA analyses revealed a total of 21 and 22 taxa across the three hypersaline lakes in sediment and water, respectively. Within both substrates, the highest diversity was found in Salar de Tara (15 taxa within sediment and 13 taxa from water). Our multi-assay design was able to detect a range of resident hypersaline taxa with different conservation status, spanning from rotifers (Encentrum) to endangered snails (Heleobia atacamensis), to amphipods (Hyalella) and flamingos (Pheonicopterus). Macroinvertebrate presence/absence data derived from conventional kick-net surveys further validated Salar de Tara as the most biodiverse system. Compared to net-based assessments, eDNA analysis allowed more refined taxonomic assignments for copepods and ostracods, while certain taxa such as Ephydridae or Hirudinea were not detected through molecular tests. Overall, this study provides evidence that eDNA is an effective tool to elucidate fine scale taxa assemblages and can refine conservation efforts in hypersaline lakes. Given the fast pace of research developments in the field of molecular ecology, eDNA hosts great potential to become a central actor in hypersaline bioassessments in the near future.

ecology↗

bioRxiv2023

Exploring the prokaryote-eukaryote interplay in microbial mats from an Andean athalassohaline wetland

Microbial community assembly results from the interaction between biotic and abiotic factors. However, environmental selection is thought to predominantly shape communities in extreme ecosystems. Salar de Huasco, situated in the high altitude Andean Altiplano, represents a poly-extreme ecosystem displaying spatial gradients of physicochemical conditions. To disentangle the influence of abiotic and biotic factors, we studied prokaryotic and eukaryotic communities from microbial mats and underlying sediments across contrasting areas of this athalassohaline ecosystem. The prokaryotic communities were primarily composed of bacteria, notably including a significant proportion of photosynthetic organisms like Cyanobacteria and anoxygenic photosynthetic members of Alpha- and Gammaproteobacteria and Chloroflexi. Additionally, Bacteroidetes, Verrucomicrobia, and Deltaproteobacteria were abundantly represented. Among eukaryotes, photosynthetic organisms (Ochrophyta, Archaeplastida) were predominant, alongside relatively abundant ciliates, cercozoans, and flagellated fungi. Salinity emerged as a key driver for the assembly of prokaryotic communities. Collectively, abiotic factors influenced both prokaryotic and eukaryotic communities, particularly those of algae. However, prokaryotic communities strongly correlated with photosynthetic eukaryotes, suggesting a pivotal role of biotic interactions in shaping these communities. Co-occurrence networks suggested potential interactions between different organisms, such as diatoms with specific photosynthetic and heterotrophic bacteria or with protist predators, indicating influences beyond environmental selection. While some associations may be explained by environmental preferences, the robust biotic correlations, alongside insights from other ecosystems and experimental studies, suggest that symbiotic and trophic interactions significantly shape microbial mat and sediment microbial communities in this athalassohaline ecosystem.

microbiology↗

bioRxiv2021

Nucleocapsid mutations in SARS-CoV-2 augment replication and pathogenesis.

While SARS-CoV-2 continues to adapt for human infection and transmission, genetic variation outside of the spike gene remains largely unexplored. This study investigates a highly variable region at residues 203-205 in the SARS-CoV-2 nucleocapsid protein. Recreating a mutation found in the alpha and omicron variants in an early pandemic (WA-1) background, we find that the R203K+G204R mutation is sufficient to enhance replication, fitness, and pathogenesis of SARS-CoV-2. The R203K+G204R mutant corresponds with increased viral RNA and protein both in vitro and in vivo. Importantly, the R203K+G204R mutation increases nucleocapsid phosphorylation and confers resistance to inhibition of the GSK-3 kinase, providing a molecular basis for increased virus replication. Notably, analogous alanine substitutions at positions 203+204 also increase SARS-CoV-2 replication and augment phosphorylation, suggesting that infection is enhanced through ablation of the ancestral RG motif. Overall, these results demonstrate that variant mutations outside spike are key components in SARS-CoV-2s continued adaptation to human infection. Author SummarySince its emergence, SARS-CoV-2 has continued to adapt for human infection resulting in the emergence of variants with unique genetic profiles. Most studies of genetic variation have focused on spike, the target of currently available vaccines, leaving the importance of variation elsewhere understudied. Here, we characterize a highly variable motif at residues 203-205 in nucleocapsid. Recreating the prominent nucleocapsid R203K+G204R mutation in an early pandemic background, we show that this mutation is alone sufficient to enhance SARS-CoV-2 replication and pathogenesis. We also link augmentation of SARS-CoV-2 infection by the R203K+G204R mutation to its modulation of nucleocapsid phosphorylation. Finally, we characterize an analogous alanine double substitution at positions 203-204. This mutant was found to mimic R203K+G204R, suggesting augmentation of infection occurs by disrupting the ancestral sequence. Together, our findings illustrate that mutations outside of spike are key components of SARS-CoV-2s adaptation to human infection.

microbiology↗