Biology subjects

Cobos, A.

Publications and source records attributed to Cobos, A..

4 recordsLinked to original sources

bioRxiv2026

First outbreak of Lumpy Skin disease in Catalonia, Spain, 2025-2026

Lumpy skin disease (LSD) is an emerging cattle disease caused by lumpy skin disease virus (LSDV), with major impacts on the industry, being classified as a Category A disease. Although it was historically confined to Africa, LSD has expanded into the Middle East, Asia and Europe. Here, we report two LSDV genomes from the first outbreak detected in Catalonia, Spain, in October 2025. The genomes were assembled from high-throughput sequencing data generated from two homogenized skin nodules. Comparative phylogenetic analyses were performed using all available complete LSDV genomes and rpo30 gene sequences. These analyses placed the LSDV isolates detected in Catalonia within clade 1.2, closely related to the isolates recently reported in Sardinia, Italy. Our findings also support a connection between recent south-western Europe and central African strains, possibly through northern Africa, and highlight the need for more complete genomes to clarify the origin and connections among recent LSDV outbreaks.

genomics↗

bioRxiv2026

Humanized FLT3 mice display enhanced tissue engraftment and support HIV-1 persistence and rebound

Despite advances in antiretroviral therapy (ART), HIV-1 cure efforts remain hindered by viral reservoirs in long-lived myeloid cells and immune-privileged tissues that are less accessible and therefore unlikely to be assessed in human clinical trials. Consequently, there is a critical need for robust research platforms such as immune cell humanized mice to bridge preclinical and clinical HIV research. However, previously described humanized mouse models have demonstrated incomplete hematopoietic development, particularly showing low levels of NK or myeloid cells. Herein, we present the novel humanized FLT3 mouse model that develops NK cells, myeloid progenitors, monocytes, and both functional conventional (cDCs) and plasmacytoid dendritic cells (pDCs) to support HIV-1 infection. Human cord blood derived CD34+ hematopoietic stem cells (HSC) were engrafted in the FLT3 (Hu-FLT3) and NSG (Hu-NSG) mouse strains for comparison. Our data showed that while Hu-NSG and Hu-FLT3 mice have comparable human lymphocyte levels, the proportion of myeloid cells (including monocytes, pDCs and cDCs) in Hu-FLT3 mice (16.2 %) was three-fold higher than in Hu-NSG mice (5.6 %) and the proportion of NK cells was six-fold higher (12.8 % and 1.9 %, respectively). Both strains successfully supported HIV-1 infection, maintain viral replication for 17 weeks in untreated mice, and proviral DNA was detectable in peripheral blood, bone marrow and spleen. While ART effectively reduced viral load to undetectable levels in four weeks in both strains, we observed viral rebound after treatment discontinuation within 3 weeks, reaching the same levels of viral load pre-ART and mimicking what is observed in people living with HIV (PLWH).Human immune cells and HIV-1 RNA were higher in tissues of Hu-FLT3 mice compared to Hu-NSG mice, mirroring features reported in human tissue reservoirs. Our findings demonstrated that Hu-FLT3 mice support enhanced development of human innate immune cells in blood and tissues, which are associated with higher levels of HIV-1 replication compared to Hu-NSG mice. This study establishes a novel, robust and accessible in vivo platform to investigate potential HIV cure and persistence-targeting interventions with translational relevance to human therapeutic development thanks to the improved and more complete human immune repertoire in Hu-FLT3.

immunology↗

bioRxiv2026

Discovery of novel members of the Potyviridae family reveals expanded diversity, a broad host range, and evidence of fungal and oomycete infections

The family Potyviridae represents the largest and most economically important group of plant-infecting RNA viruses. Despite extensive study of crop-associated members, the full diversity, host range, and evolutionary history of potyvirids remain poorly understood. Here, we conducted a large-scale mining of publicly available RNA-seq datasets to systematically search for novel potyvirid sequences. This approach enabled the identification and assembly of 47 previously undescribed members of the family, distributed across eight recognized genera and, importantly, two putative new genera. Beyond expanding the known genetic diversity of Potyviridae, our analyses revealed a distinct and deeply divergent lineage of potyvirid-like viruses associated with fungi and oomycetes, for which we propose the genus Macrophovirus. These viruses possess compact genomes and atypical genomic organizations, including the absence of canonical plant cell-to-cell movement factors and the presence of HCPro-like proteins arranged in tandem. Comparative structural and phylogenetic analyses indicate that these leader proteases are more closely related to fungal hypoviral counterparts than to canonical potyvirid HCPro factors. Together, our findings substantially expand the host range of Potyviridae, provide compelling evidence that potyvirid-like viruses likely infect fungi and oomycetes in nature, and offer new insights into the evolutionary pathways that have shaped this major virus family.

evolutionary biology↗

bioRxiv2025

Turnip mosaic virus drives selective filtering and community reassembly in the Arabidopsis thaliana root microbiome in a genotype-specific manner

Plant root microbiomes play a central role in plant health, yet their responses to viral infection remain poorly understood. Here, we investigated how Turnip mosaic virus (TuMV) alters root-associated bacterial and fungal communities in two Arabidopsis thaliana genotypes (Col-0 and Mar-12) grown in natural soils. Using 16S and ITS amplicon sequencing, we assessed changes in diversity, taxonomic composition, enriched microbial taxa, and co-occurrence network structure to distinguish between plant-mediated recruitment ("cry-for-help") and pathogen-induced dysbiosis. TuMV infection caused a pronounced reduction in bacterial diversity and a restructuring of bacterial community composition, whereas fungal communities remained largely stable. Viral infection also led to genotype-specific shifts in enriched bacterial genera, with opportunistic and stress-tolerant taxa proliferating differently in each genotype. Despite the initial perturbation, bacterial networks recovered connectivity and, in some cases, reached higher complexity than those of healthy plants, indicating strong microbial resilience. Together, these results reveal that TuMV infection acts as a selective filter on bacterial, but not fungal, root communities and that the surviving taxa can reorganize into functional networks. Our study provides one of the most comprehensive assessments of virus-induced microbiome restructuring and highlights the importance of host genotype in shaping microbial responses to biotic stress.

plant biology↗