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Ban, M.

Publications and source records attributed to Ban, M..

5 recordsLinked to original sources

Federated single-cell QTL meta-analysis reveals novel disease mechanisms

Genetic effects on gene expression are often cell type-specific and obscured in bulk analyses. To resolve this context-dependent regulation, we performed a federated cis-eQTL meta-analysis across 12 PBMC datasets (2,032 individuals, 2.5 million cells). Across six immune cell types, we identified cis-eQTLs for 6,592 genes and fine-mapped 14,985 independent loci. Notably, the 42% of eQTLs that were undetected in a bulk eQTL study on 43,301 whole blood samples also showed stronger enrichment for disease GWAS loci. We further identified three genome-wide significant and 65 suggestive loci affecting the abundance of (rare) immune cell types and validated these using previously reported hematological GWAS and bulk-derived trans-eQTLs. Integrating single-cell cis-eQTLs with bulk trans-eQTLs enabled us to anchor 6,382 trans-eGenes (37.2% novel) to upstream regulators and reconstruct directed gene regulatory relationships. For example, a hemorrhoidal disease-associated variant showed a CD4+ T cell-specific cis-eQTL on BACH1 that colocalized with 45 immune and metabolic trans-eGenes. These results demonstrate the power of single-cell QTL meta-analysis in interpreting complex trait genetics.

genetics↗

Vector Competence of Temperate and Tropical Mosquito Species for Babanki virus

Babanki virus (BBKV), an alphavirus belonging to the Western Equine encephalitis complex, was isolated from Mansonia africana mosquitoes in 1969 but is not characterized yet. Transmitted to humans and animals through the bite of an infectious female arthropod, it is associated with febrile illness, rash, and arthritis similarly to Sindbis virus to which it is related. No specific treatment or vaccine is available. To investigate any risk of propagation, our study investigated the vector competence of several mosquito species towards BBKV. For this purpose, laboratory mosquito colonies from metropolitan France: Culex pipiens (Paris), Aedes albopictus (Nice) as well as tropical area: Aedes albopictus (Saint-Benoit, La Reunion) and Culex quinquefasciatus (Slab strain), Aedes aegypti (PAEA) were exposed to an artificial blood meal infected with BBKV molecular clone. Midguts, legs, salivary glands and saliva were collected from individual mosquitoes of different strains or species at various time points to assess the infection status, viral replication, and infectiousness. At 7 days post viral exposure, infection rates exceeded 70% in Aedes and 40% in Culex species. They remain above 50% except for Culex quinquefasciatus which decreases to 35% at 14 days post viral exposure. Using genome and protein detection, the dissemination rates are above 50% except for Aedes albopictus (Nice) at 7 days post viral exposure. Infection assays using VeroE6 cells indicated that BBKV replicative viral particles were found in the saliva of the different populations tested. Our data demonstrate that different mosquitoes species from both temperate and tropical areas are competent to transmit BBKV suggesting an emergence risk that could trigger an outbreak in humans. Author SummaryBabanki virus (BBKV) is a non-characterized arbovirus identified in 1969 in Cameroon. BBKV is closely related to Sindbis virus which causes symptoms like febrile illness, rash, and arthritis in humans and animals. Both are alphaviruses within the Western Equine Encephalitis complex. BBKV is identified only in the African continent so far. Despite its potential to cause disease, no effective treatments are available. This study investigates the vector competence of various mosquito species from temperate and tropical regions, to transmit BBKV. After mosquitoes were fed an infectious blood meal, various organs were collected at different time points to assess the infection status, viral replication, and infectiousness. The results showed that BBKV infection occurred in all tested mosquito species and persisted over time, with viral particles detected in mosquito or that can potentially be transmitted to vertebrate hosts via mosquito saliva. These findings highlight the broad vector competence of mosquitoes from diverse climatic regions for BBKV, indicating its potential risk for emergence and outbreaks in different regions of the world. The study emphasizes the need for enhanced surveillance and preventive measures to mitigate the potential threat posed by this emerging virus.

microbiology↗

Experimental comparison of mowing and mulching on snail communities in wet meadows

The condition of wet meadows nowadays depends mainly on human activities; the biodiversity and productivity of these habitats can only be maintained by appropriate management methods. Mowing and grazing are well-known traditional methods, but a new method, regular mulching - the fragmentation of plant material and its deposition in the area - is also increasingly used. The ecological impact of traditional management is still not fully known, and we know almost nothing about the effects of mulching. To better understand the impact of these methods we directly compared their effects on snails, an invertebrate taxon common in these habitats and known as good bioindicators. We experimentally manipulated management methods on two wet meadows in Northern Hungary, Europe, and surveyed their snail communities immediately before and one year after treatments. Our results showed that mowing had a detectable negative effect on the snail communities. On the other hand, mulching did not alter their characteristics. Therefore, mulching may be a more desirable method for short-term interventions on wet meadows, whilst at the same time also preserving their biodiversity.

ecology↗

Heritage of ancient cultures supports conservation: a continent-wide perspective from the Eurasian steppes

Civilisations including ancient ones, have shaped the global ecosystems in many ways through a co-evolution of landscapes and humans. However, the cultural legacies of ancient and lost civilisations are seldom considered in conservation. Here using a continental-scale dataset containing over 1,000 data records on the localities, land cover, protection status and cultural values related to ancient steppic burial mounds (so-called kurgans), we evaluated how these iconic and widespread landmarks can contribute to grassland conservation in the Eurasian steppes, which is one of the most endangered biomes on Earth. By using Bayesian logistic generalized regressions and proportional odds logistic regressions, we aimed to reveal the potential of mounds in preserving grasslands considering landscapes with different levels of land use transformation. We also compared the conservation potential of mounds situated inside and outside protected areas and assessed whether the presence of cultural, historical or spiritual values support the maintenance of grasslands on them. We revealed that kurgans have enormous importance in preserving grasslands in transformed landscapes outside protected areas, where they can act as habitat islands, and provide an additional pillar for conservation by contributing to habitat conservation and improvement of habitat connectivity. We found that besides their steep slopes hindering ploughing, the existence of cultural, historical or religious values could almost double the chance for grassland occurrence on kurgans due to the related extensive land use and the respect of local communities. As the estimated number of steppic mounds is about 600,000 and also similar historical features exist in all continents, our results can be upscaled to a global level. Our results also suggest that an integrative socio-ecological approach in conservation might support the positive synergistic effects of conservational, landscape and cultural values.

ecology↗

Spatio-temporal structure and reproductive success in a rook (Corvus frugilegus) colony

We have studied how individual decisions about timing of breeding and nest location affected the reproductive success of rooks by tracing the formation of a rook breeding colony in Hortobagy NP (Hungary), during the breeding season in 1999.\n\nWe have found that birds who built nests earlier also laid eggs earlier and had larger clutch size but had no had more offspring than late nesters. Distance of the nest from the centre or edge of the colony did not affect the reproductive success though rooks generally settled closer to the centre and further from the edge than it can be expected by assuming random distribution. The colony showed high breeding synchrony since date of egg laying varied less than date of nesting but synchrony did not influence the breeding success. Hatchlings survival rate and number of offspring increased with local nest density and rooks clustered their nests more than it can be expected by random settlement. Nest sites of early and late nesters did not differ regarding the distance from the centre or the edge of the colony but late nesters chose nest sites in more densely populated regions.\n\nThe results indicate that individuals may follow different strategies to increase their reproductive success. It is prospectively advantageous to build the nest and lay eggs earlier, in turn, its worth nesting in already more densely nested areas for late beginners. We suggest that a game theoretical approach may be useful if we try to understand the adaptive significance of colonial breeding.

animal behavior and cognition↗