Biology subjects

Moya, P.

Publications and source records attributed to Moya, P..

3 recordsLinked to original sources

bioRxiv2025

Symbiotic versatility in action: Trebouxia diversity expands the niche of the lichen Xanthoria parietina

AimWe explored the phylogenetic diversity of the mycobiont Xanthoria parietina and its associated Trebouxia phycobionts across the Mediterranean region and examined how photobiont climatic preferences may shape the ecological amplitude and spatial distribution of the lichen. LocationSpecimens were collected in different localities in the central and western Mediterranean Basin (Iberian and Italian peninsulas), with additional Atlantic and boreal localities used for comparison. MethodsGenetic diversity and phylogenies of both lichen symbionts were inferred from nrITS data. Mycobiont-phycobiont interaction networks were constructed, and ecological niches of associated Trebouxia species were modelled using 19 bioclimatic variables from WorldClim v. 2.1. ResultsPhylogenetic analyses revealed high diversity within Xanthoria parietina and clarified the placement of poorly studied species within the genus Xanthoria (e.g., X. monofoliosa and X. aureola s. lat.), and revealed a novel lineage (Xanthoria sp. hydra). All the photobionts belonged to Trebouxia clade A; nine Trebouxia species-level lineages were detected, including a previously unrecognized lineage (Trebouxia sp. A56). Trebouxia decolorans (A33) was the most frequent photobiont and exhibited the broadest climatic niche, whereas T. solaris (A35) and T. tabarcae ad int. (A48) showed a more specialized climatic niche. Ensemble species-distribution models indicated widespread suitability for T. decolorans across Europe, and more coastal-Mediterranean suitability for T. tabarcae ad int. Main ConclusionXanthoria parietina displays remarkable symbiont flexibility in associating with various Trebouxia lineages within clade A, which contribute to its ecological success in heterogeneous Mediterranean environments. Climatic niche modelling suggests that the association with different phycobionts may expand the ecological niche of the lichen, potentially enhancing its capacity to inhabit a wider range of environmental conditions.

ecology↗

bioRxiv2025

Cognitive Resilience in Aging Degus is Linked to CA3 Hippocampal GABAergic Integrity

The preservation of cognitive function during aging remains a key challenge in neuroscience. In this study, we applied an integrative approach, combining behavioral assays with neurophysiological recordings, to investigate hippocampal circuit integrity. We used Octodon degus, a rodent with exceptional longevity (up to 10 years in laboratory conditions), as a natural model of aging and neurodegenerative disease such as Alzheimer. To assess agerelated cognitive changes, we employed three behavioral tasks: Novel Object Recognition (NOR), Open Field (OF), and the Burrowing Test (BT). The BT reflects Activities of Daily Living (ADLs) and is based on species-typical spontaneous burrowing behavior, which has been linked to neurodegenerative markers in degus. We also performed multielectrode electro-physiological recordings to assess GABAergic function in the hippocampus. Aged degus with high BT performance (classified as good burrowers, or GB) showed robust hippocampal activity, especially in the CA3 region, a key hub for signal integration and memory encoding. In contrast, degus with poor BT performance (bad burrowers, or BB) exhibited reduced spontaneous hippocampal activity, suggesting potential compensation via GABA-independent synaptic mechanisms. Altogether, our findings suggest that preserved GABAergic function supports cognitive resilience in aging degus. These results offer new insights into the neural mechanisms underlying healthy cognitive aging and may inform future strategies for preventing or mitigating neurodegeneration.

neuroscience↗

bioRxiv2020

Symbiosis between river and dry lands: phycobiont dynamics on river gravel bars

River gravel bars are dynamic and heterogeneous habitats standing on transition between aquatic and terrestrial environment. Periodical flooding, low nutrient content, frost, missing safe sites, drought, and heat on the ground surface significantly influence life in these habitats. Mutualistic symbiosis may be a successful strategy for organisms to survive and to proliferate under harsh conditions. The lichen genus Stereocaulon was selected as a model symbiotic system among the organisms living on river gravel bars. The aim of our work was to determine effect of this dynamic environment on a phycobiont (i.e., green eukaryotic photobiont) community structure. We analysed 147 Stereocaulon specimens collected in the Swiss Alps using Sanger sequencing (fungal ITS rDNA, algal ITS rDNA, algal actin type I gene) and 8 selected thalli and 12 soil samples using Illumina metabarcoding (ITS2 rDNA). We performed phytosociological sampling on each study plot (n=13). Our analyses of communities of phycobionts, lichens, bryophytes, and vascular plants indicated an ongoing colonisation by phycobionts and gradual change of phycobiont community along to the successional gradient. We recovered great phycobiont diversity associated with Stereocaulon mycobionts including algae reported as phycobionts for the first time. Each of two Stereocaulon mycobiont OTUs has distinct pool of predominant phycobionts in the study area. Finally, all thalli selected for Illumina metabarcoding contained a wide range of additional intrathalline algae, i.e., showed algal plurality. In general, succession process on newly emerged or recently disturbed localities also takes place within a community of microscopic symbiotic organisms, such as phycobionts.

ecology↗