Biology subjects

Latorre, A.

Publications and source records attributed to Latorre, A..

8 recordsLinked to original sources

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↗

bioRxiv2025

Ecology and demographic structure of an extinct ibex population in Upper Palaeolithic Italian Alps

Alpine Upper Palaeolithic contexts exhibit specialised subsistence strategies, heavily dependent on Capra ibex. Among them, the rock shelter Riparo Dalmeri stands out, with C. Ibex dominating faunal remains across all occupation phases, spanning the Pleistocene/Holocene transition. This evidence positions Riparo Dalmeri as a key site for exploring the interdependence between human groups and C. ibex during one of the most critical climatic and cultural shifts in human evolution. Here, we present the first multidisciplinary study on Late Palaeolithic C. ibex teeth from Riparo Dalmeri, integrating direct radiocarbon dating, isotope (87Sr/86Sr, {delta}13C, {delta}18O), proteomic, and aDNA analyses. We generated the earliest aDNA sequences for C. ibex and contextual evidence on mobility, seasonality, and sex ratios. We found that most C. ibex were local to the area despite consistent human presence. They reveal significant dietary differences between sexes as well as increased seasonality at the Pleistocene-Holocene transition. Our results identify Riparo Dalmeri as an extinct branch of the ibex mtDNA phylogeny, offering unprecedented insights into ibex ecology and evolution that resonate with present-day issues on the conservation of this species in the face of climate change.

ecology↗

bioRxiv2024

Failed Double-Blind Replication of Offline 5Hz-rTUS-Induced Corticospinal Excitability

IntroductionTranscranial ultrasound stimulation (TUS) is a promising new form of non-invasive neuromodulation. As a nascent technique, replication of its effects on brain function is important. Of particular interest is offline 5Hz repetitive TUS (5Hz-rTUS), originally reported by Zeng and colleagues [1] to elicit lasting corticospinal excitability increases, with large effect sizes. Material and methodHere, we conducted a pre-registered (https://osf.io/p5n4q) replication of this protocol that benefitted from three additional features: double-blind application of TUS, neuronavigation for consistent TMS positioning, and acoustic simulations to assess M1 target exposure to TUS. Changes in resting motor thresholds (rMT), motor-evoked potential (MEP) amplitude, short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) in response to TUS (5Hz-rTUS vs. sham) were measured in the right first dorsal interosseous (FDI), abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles, with unbiased selection of participants. Transducer location was determined by the TMS-hotspot for motor representations of the right FDI, as in the original work. ResultsNo significant effects of 5Hz-TUS (vs sham) were observed. Post-hoc simulations showed considerable variability of the acoustic focus, which was outside the anatomical M1-hand area in 67% of participants - in line with the known poor correspondence of TMS-hotspot location and M1-hand area. ConclusionOur results indicate that the effect sizes of the neuromodulatory effects of 5Hz-rTUS on M1 may be more variable than previously appreciated. We suggest that double-blinding, neuronavigated TMS, individualised acoustic simulations for TUS targeting and pre-registration will aid reproducibility across studies.

neuroscience↗

bioRxiv2023

Retrospective Evaluation of the Eye Irritation Potential of Agrochemical Formulations

While multiple in vitro eye irritation methods have been developed and adopted as OECD health effects test guidelines, only one is considered a complete replacement for the in vivo rabbit eye test for classification and labelling for eye irritation hazard. Additionally, for most of the adopted methods there is a data gap on the applicability to predict the ocular irritation potential of agrochemical formulations. To overcome this data gap, a retrospective evaluation of 192 agrochemical formulations with in vivo (OECD TG 405) or in vitro (OECD TG 437, 439, or 492) data was conducted to determine if the in vitro methods could accurately assign United Nations Globally Harmonized System for Classification and Labelling of Chemicals (GHS) eye irritation hazard classifications. In addition, for each of the final formulations and their individual components, we also conducted an evaluation of the GHS concentration threshold (CT) approach. The results herein suggest that the four individual methods and GHS CT approach were highly predictive of formulations that would not require classification for eye irritation hazard. Given most agrochemical formulations fall into this category, methods that accurately identify not classified mixtures could significantly reduce the use of animals for this endpoint.

pharmacology and toxicology↗

bioRxiv2020

Non-invasive Amelioration of Essential Tremor via Phase-Locked Disruption of its Temporal Coherence

Aberrant neural oscillations hallmark numerous brain disorders. Here, we first report a method to track the phase of neural oscillations in real-time via endpoint-corrected Hilbert transform (ecHT) that mitigates the characteristic Gibbs distortion. We then used ecHT to show that the aberrant neural oscillation that hallmarks essential tremor (ET) syndrome, the most common adult movement disorder, can be noninvasively suppressed via electrical stimulation of the cerebellum phase-locked to the tremor. The tremor suppression is sustained after the end of the stimulation and can be phenomenologically predicted. Finally, using feature-based statistical-learning and neurophysiological-modelling we show that the suppression of ET is mechanistically attributed to a disruption of the temporal coherence of the oscillation via perturbation of the tremor generating a cascade of synchronous activity in the olivocerebellar loop. The suppression of aberrant neural oscillation via phase-locked driven disruption of temporal coherence may represent a powerful neuromodulatory strategy to treat brain disorders.

neuroscience↗

bioRxiv2020

Tracking evolutionary trends towards increasing complexity: a case study in Cyanobacteria

Progressive evolution, the tendency towards increasing complexity, is a controversial issue in Biology, whose resolution requires a proper measurement of complexity. Genomes are the best entities to address this challenge, as they record the history and information gaining of organisms in their ongoing biotic and environmental interactions. Using six metrics of genome complexity, none of which is primarily associated to biological function, we measure genome complexity in 91 genomes from the phylum Cyanobacteria. Several phylogenetic analyses reveal the existence of progressive evolution towards higher genome complexity: 1) all the metrics detect strong phylogenetic signals; 2) ridge regressions detect positive trends towards higher complexity; and 3) classical proofs for progressive evolution (the minimum, the ancestor-descendent and the sub-clade tests), show that some of these positive trends are driven, being mainly due to natural selection. These findings support the existence of progressive genome evolution in this ancient and diverse group of organisms.

evolutionary biology↗

bioRxiv2018

To B or not to B: Arsenophonus as a source of B-vitamins in whiteflies.

1Insect lineages feeding on nutritionally restricted diets such as phloem, xylem, or blood, were able to diversify by acquiring bacterial species that complemented the missing nutrients. These bacteria, considered obligate/primary endosymbionts, share a long evolutionary history with their hosts. In some cases, however, these endosymbionts are not able to fulfill all the nutritional requirements of their host, driving the acquisition of additional symbiotic species. Whiteflies, which feed on phloem, established an obligate relationship with Candidatus Portiera aleyrodidarum, who provides essential amino acids and carotenoids to the host. As many Whiteflies species harbor additional endosymbionts, they could provide their hosts with missing nutrients. To test this hypothesis, genomes of several endosymbionts from the whiteflies Aleurodicus dispersus, A. floccissimus and Trialeurodes vaporariorum were sequenced and analyzed. All three species were found to harbor an endosymbiont from the genus Arsenophonus, and the two former also host Wolbachia. A comparative analysis of the three Arsenophonus genomes revealed that although all of them are capable of synthesizing B-vitamins and cofactors, such as pyridoxal, riboflavin, or folate, their genomes and phylogenetic relationship vary greatly. Arsenophonus of A. floccissimus and T. vaporariorum belong to the same clade and display characteristics of facultative endosymbionts, such as large genomes (3 Mb) with thousands of genes, many pseudogenes, intermediate GC content, and mobile genetic elements (MGEs). In contrast, Arsenophonus of A. dispersus belongs to a different lineage and displays the characteristics of a primary endosymbiont, such as a reduced genome (670 kb) with 400 genes, 32% GC content, and no MGEs. However, the presence of 274 pseudogenes suggests that this symbiotic association is more recent than other reported hemipterans primary endosymbionts. Arsenophonus of A. dispersus gene repertoire is completely integrated in the symbiotic consortia, and the biosynthesis of most vitamins occurs in shared pathways with its host. In addition, Wolbachia have also retained the ability to produce riboflavin, FAD, and folate, and may have a nutritional contribution. Taken together, our results show that Arsenophonus have a pivotal place in whiteflies nutrition by their ability to produce B-vitamins, even if they diverge and/or go through a genome reduction process.

microbiology↗

bioRxiv2017

A genome-scale study of metabolic complementation in endosymbiotic consortia: the case of the cedar aphid

Bacterial endosymbionts and their insect hosts establish an intimate metabolic relationship. Bacteria offer a variety of essential nutrients to their hosts, whereas insect cells provide the necessary sources of matter and energy to their tiny metabolic allies. These nutritional complementations sustain themselves on a diversity of metabolite exchanges between the cell host and the reduced yet highly specialized bacterial metabolism -which, for instance, overproduces a small set of essential amino acids and vitamins. A well-known case of metabolic complementation is provided by the cedar aphid Cinara cedri that harbors two co-primary endosymbionts, Buchnera aphidicola BCc and Ca. Serratia symbiotica SCc, and in which some metabolic pathways are partitioned between different partners. Here we present a genome scale metabolic network (GEM) for the bacterial consortium from the cedar aphid iBSCc. The analysis of this GEM allows us the confirmation of cases of metabolic complementation previously described by genome analysis (i.e. tryptophan and biotin biosynthesis) and the proposal of a hitherto unnoticed event of metabolic pathway sharing between the two endosymbionts, namely the biosynthesis of tetrahydrofolate. In silico knock-out experiments with iBSCc showed that the consortium metabolism is a highly integrated yet fragile network. We also have explored the evolutionary pathways leading to the emergence of metabolic complementation between reduced metabolisms starting from individual, complete networks. Our results suggest that, during the establishment of metabolic complementation in endosymbionts, adaptive evolution is more significant than previously thought.

systems biology↗