Biology subjects

Ortego, J.

Publications and source records attributed to Ortego, J..

9 recordsLinked to original sources

bioRxiv2026

Climate adaptation across space and time: lessons from oak populations

Tree populations can respond to climate change through migration, phenotypic plasticity, or genetic evolution. Despite long generation times of forest tree species, recent studies suggest that their evolutionary responses may occur rapidly. Using oaks as a model system, we synthesize evidence from 88 common garden studies and from historical, retrospective and longitudinal approaches to explore how populations have adapted to climatic variability across different biomes, and assess the consistency and pace of evolutionary responses across spatial and temporal climatic gradients. We found that approximately 61% of the studies exhibited significant differences among populations but climatic drivers and adaptive strategies differed among biomes. Temperature-related clines predominated in temperate regions, with populations from warmer origins showing longer growing seasons and higher growth potential. In seasonally dry biomes, aridity favored increased drought tolerance in Mediterranean populations but drought avoidance in tropical populations. Allochronic studies revealed genetic changes over decades to millenia in response to climate changes, with warming associated with increased growth and reduced specific leaf area in temperate oaks. Thus, spatial differentiation and temporal evolution were generally congruent in direction for most traits except for leaf unfolding, while short-term evolutionary rates exceeded long-term estimates by two to three orders of magnitude. In summary, provenance trials can provide useful information on the direction of climate-driven evolution for some traits, but may underestimate its contemporary pace. More studies are needed to evaluate whether standing genetic variation of forest tree species is sufficient to track current climate change.

evolutionary biology↗

bioRxiv2026

Chromosome-level genome assembly and annotation of the threatened marbled teal (Marmaronetta angustirostris)

The marbled teal (Marmaronetta angustirostris) is a widely distributed but declining waterfowl species, classified as Near Threatened globally and Critically Endangered in Spain. Despite ongoing conservation actions, including ex situ management and population reinforcement programmes, the genomic consequences of long-term captivity, inbreeding, and patterns of functional genetic variation remain unknown due to the absence of a species-specific reference genome. Here, we present the first chromosome-level genome assembly for this species. The genome was generated using PacBio HiFi long reads and Omni-C data, yielding a 1.15Gb assembly with a scaffold N50 of 76.95Mb. A total of 97.16% of the assembly was anchored into 36 chromosome-scale scaffolds, including the Z and W sex chromosomes. BUSCO analysis recovered 99.2% of conserved avian genes. Gene prediction was performed using both ab initio and homology-based strategies, resulting in 16,048 protein-coding genes. This resource provides a foundation for genomewide analyses of inbreeding, demographic history, and adaptive variation, and will support evidencebased in situ and ex situ conservation strategies for this threatened species.

genomics↗

bioRxiv2026

Genomic footprints of selfing, introduction history, and long-distance dispersal in an invasive alien plant

Biological invasions are natural experiments for studying the evolutionary and ecological processes underlying colonization success and range expansion. Using genome-wide data -- generated via genotyping-by-sequencing (GBS) from 30 populations spanning Europe and South Africa-- we investigated the colonization history and successful spread of the invasive buttonweed Cotula coronopifolia, an annual plant introduced into Europe from South Africa about 300 years ago. Our analyses identified three major lineages in Europe distributed across the continent, often co-occurring without evidence of admixture. Phylogenomic dating revealed that these lineages diverged > 2,000 years ago --well before the earliest European records-- suggesting divergence within the native range and either multiple introductions or a single introduction with multiple lineages. Mating-system inference shows that reproduction occurs primarily via self-fertilization ([~]70% on average), although outcrossing predominates in some populations, revealing a facultative mating system. This high selfing rate has led to extremely low heterozygosity in most populations and a strong genetic structure. Genetic clustering also revealed admixed individuals resulting from rare inter-lineage outcrossing; comparisons of empirical and simulated data indicate that increased diversity after sporadic admixture events decays rapidly under subsequent selfing. Both the introduction history and long-distance dispersal facilitated by waterbirds likely explain the scattered distribution of lineages across Europe. Altogether, these results provide an empirical demonstration of Bakers "ideal weed" concept, highlighting the role of a flexible mating system in providing reproductive assurance during colonization and showing how predominant selfing shapes the genomic landscape of an invasive species. SIGNIFICANCE STATEMENTUnderstanding how reproductive strategies influence colonization and spread of alien species is central to invasion biology. By combining population genomics and phylogenomic inference, this study provides key insights into the colonization history and successful invasion of the self-fertilizing plant C. coronopifolia, introduced from South Africa to Europe in the 18th century. We show that the species invasion success relies on the introduction of multiple lineages and the predominance of selfing, which has drastically reduced genetic diversity yet contributed to reproductive assurance and spread across diverse habitats. Occasional outcrossing and long-distance dispersal by waterbirds or through horticultural transport have further shaped the species genetic landscape. These findings illustrate how self-compatibility and ecological generalism can overcome genetic constraints during range expansion and provide the basis for understanding the evolutionary dynamics of selfing plant invasions.

genomics↗

bioRxiv2025

Generation and characterization of an ovine cell line derived from peripheral blood and its potential use to study livestock and zoonotic viral infections

BackgroundMesenchymal stromal cells (MSCs) are a population of undifferentiated non-hematopoietic fibroblast-like cells isolated from several tissues with multipotent differentiation capacity in vitro. This study focused on the establishment and characterization of a mesenchymal stromal cell line derived from ovine peripheral blood mononuclear cells (PBMCs). MethodsMSC were isolated from ovine blood and used to develop a cell line. The characterization of the cell line to confirm its mesenchymal origin was carried out by different assays. First at all, cells were characterized by flow cytometry (FACS) using monoclonal antibodies specific for MSC and hematopoietic non-stromal cell surface antigens. Real-time quantitative PCR (RT-qPCR) was performed using gene primer pairs specific for hematopoietic and mesenchymal cell surface markers. In addition, we assayed the potential of the cell line to differentiate in vitro to other lineages such as osteoblasts and neurons and confirmed that by specific staining with Alizarin Red (AR) and RT-qPCR and immunofluorescence (IFA). Finally, we assayed the susceptibility of the cell line to various livestock, animal and human viruses. ResultsFACS and RT-qPCR analyses revealed that the ovine cell line expressed mesenchymal markers and was negative for hematopoietic markers assayed. MSC were able to differentiate to osteoblasts and neurons, these results were confirmed by quantitative analyses of AR staining and RT-qPCR and IFA assays. The cell line showed susceptibility to infection with all viruses assayed confirmed by IFA asssays. ConclusionsIn this work, we used isolated MSCs from peripheral blood to establish a new ovine cell line. The characterization and the osteogenic and neuronal differentiation carried out confirmed that the cell line had a mesenchymal stromal origin. In fact, the new established ovine cell line was permissive to all viruses studied in this work. The new sheep cell line could be a useful tool for isolating and characterizing viruses and studying virus-host interactions.

cell biology↗

bioRxiv2021

Genomic evidence of speciation by fusion linked to trophic niche expansion in a recent radiation of grasshoppers

Post-divergence gene flow can trigger a number of creative evolutionary outcomes, ranging from the transfer of beneficial alleles across species boundaries (i.e., adaptive introgression) to the formation of new species (i.e., hybrid speciation). While neutral and adaptive introgression has been broadly documented in nature, hybrid speciation is assumed to be rare and the evolutionary and ecological context facilitating this phenomenon still remains controversial. Through combining genomic and phenotypic data, we evaluate the hypothesis that the dual feeding regime (scrub legumes and gramineous herbs) of the taxonomically controversial grasshopper Chorthippus saulcyi algoaldensis resulted from hybridization between two sister taxa that exhibit contrasting host-plant specializations: C. binotatus (scrub legumes) and C. saulcyi (gramineous herbs). Genetic clustering analyses and inferences from coalescent-based demographic simulations confirmed that C. s. algoaldensis represents a uniquely evolving lineage and supported the ancient hybrid origin of this taxon (ca. 1.4 Ma), which provides a mechanistic explanation for its broader trophic niche and sheds light on its uncertain phylogenetic position. We propose a Pleistocene hybrid speciation model where range shifts resulting from climatic oscillations can promote the formation of hybrid swarms and facilitate its long-term persistence through geographic isolation from parental forms in topographically complex landscapes.

genetics↗

bioRxiv2021

Reticulate Evolutionary History in a Recent Radiation of Montane Grasshoppers Revealed by Genomic Data

Inferring the ecological and evolutionary processes underlying lineage and phenotypic diversification is of paramount importance to shed light on the origin of contemporary patterns of biological diversity. However, reconstructing phylogenetic relationships in recent evolutionary radiations represents a major challenge due to the frequent co-occurrence of incomplete lineage sorting and introgression. In this study, we combined high throughput sequence data (ddRADseq), geometric morphometric information, and novel phylogenetic inference methods that explicitly account for gene flow to infer the evolutionary relationships and the timing and mode of diversification in a complex of Ibero-Maghrebian montane grasshoppers of the subgenus Dreuxius (genus Omocestus). Our analyses supported the phenotypic distinctiveness of most sister taxa, two events of historical introgression involving lineages at different stages of the diversification continuum, and the recent Pleistocene origin (< 1 Ma) of the complex. Phylogenetic analyses did not recover the reciprocal monophyly of taxa from Iberia and northwestern Africa, supporting overseas migration between the two continents during the Pleistocene. Collectively, these results indicate that periods of isolation and secondary contact linked to Pleistocene glacial cycles likely contributed to both allopatric speciation and post divergence gene flow in the complex. This study exemplifies how the integration of multiple lines of evidence can help to reconstruct complex histories of reticulated evolution and highlights the important role of Quaternary climatic oscillations as a diversification engine in the Ibero-Maghrebian biodiversity hotspot.

evolutionary biology↗

bioRxiv2021

Glacial connectivity and current population fragmentation in sky-islands explain the contemporary distribution of genomic variation in two narrow-endemic montane grasshoppers from a biodiversity hotspot

AimCold-adapted biotas from mid-latitudes often show small population sizes, harbor low levels of local genetic diversity, and are highly vulnerable to extinction due to ongoing climate warming and the progressive shrink of montane and alpine ecosystems. In this study, we use a suite of analytical approaches to infer the demographic processes that have shaped contemporary patterns of genomic variation in Omocestus bolivari and O. femoralis, two narrow-endemic and red-listed Iberian grasshoppers forming highly fragmented populations in the sky island archipelago of the Baetic System. LocationSoutheastern Iberia. MethodsWe quantified genomic variation in the two focal taxa and coupled ecological niche models and a spatiotemporally explicit simulation approach based on coalescent theory to determine the relative statistical support of a suite of competing demographic scenarios representing contemporary population isolation (i.e., a predominant role of genetic drift) vs. historical connectivity and post-glacial colonization of sky islands (i.e., pulses of gene flow and genetic drift linked to Pleistocene glacial cycles). ResultsInference of spatial patterns of genetic structure, environmental niche modelling, and statistical evaluation of alternative species-specific demographic models within an Approximate Bayesian Computation framework collectively supported genetic admixture during glacial periods and postglacial colonization of sky islands, rather than long-term population isolation, as the scenario best explaining the current distribution of genomic variation in the two focal taxa. Moreover, our analyses revealed that isolation in sky islands have also led to extraordinary genetic fragmentation and contributed to reduce local levels of genetic diversity. Main conclusionsThis study exemplifies the potential of integrating genomic and environmental niche modelling data across biological and spatial replicates to determine whether organisms with similar habitat requirements have experienced concerted/idiosyncratic responses to Quaternary climatic oscillations, which can ultimately help to reach more general conclusions about the vulnerability of mountain biodiversity hotspots to ongoing climate warming.

evolutionary biology↗

bioRxiv2019

Safeguarding the genetic integrity of native pollinators requires stronger regulations on commercial lines

Every year more than one million commercial bumblebee colonies are deployed in greenhouses worldwide for its pollination services to several commercially important crops such as tomato and different species of berries. While commercial pollinators have been an enormous benefit for the production of essential food crops and for achieving higher yields and better fruit quality at a low cost, their use is emerging also as an important threat to wild pollinators. Commercial pollinators have been linked to pathogen spillover to wild species, and its introduction outside its native area have had devastating effects on native pollinator populations. However, a more pervasive, but underappreciated threat is their potential impact on the genetic integrity of native pollinators. Here, we show clear evidence of generalized hybridization between native and introduced commercial bumblebee lineages in southern Spain. The signal of genetic introgression is widespread and already expands up to 60 km from main commercial bumblebee release areas. As pollination services demand is predicted to increase in the coming years, only a more restrictive regulation of commercial lines could mitigate their negative impacts on the genetic integrity of native pollinators and prevent the disruption of local adaptations.

ecology↗

bioRxiv2017

Ecological drivers of body size evolution and sexual size dimorphism in short-horned grasshoppers (Orthoptera: Acrididae)

Sexual size dimorphism (SSD) is widespread and variable in nature. Although female-biased SSD predominates among insects, the proximate ecological and evolutionary factors promoting this phenomenon remain largely unstudied. Here, we employ modern phylogenetic comparative methods on 8 subfamilies of Iberian grasshoppers (85 species) to examine the validity of different models of evolution of body size and SSD and explore how they are shaped by a suite of ecological variables (habitat specialization, substrate use, altitude) and/or constrained by different evolutionary pressures (female fecundity, strength of sexual selection, length of the breeding season). Body size disparity primarily accumulated late in the history of the group and did not follow a Brownian motion pattern, indicating the existence of directional evolution for this trait. We found support for the converse of Renschs rule across all taxa but not within the two most speciose subfamilies (Gomphocerinae and Oedipodinae), which showed an isometric pattern. Our results do not provide support for the fecundity or sexual selection hypotheses and we did not find evidence for significant effects of habitat use. Contrary to that expected, we found that species with narrower reproductive window are less dimorphic in size than those that exhibit a longer breeding cycle, suggesting that male protandry cannot solely account for the evolution of female-biased SSD in Orthoptera. Our study highlights the need to consider alternatives to the classical evolutionary hypotheses when trying to explain why in certain insect groups males remain small.

evolutionary biology↗