Biology subjects

Tadesse, D.

Publications and source records attributed to Tadesse, D..

5 recordsLinked to original sources

bioRxiv2026

Chromosome-scale genome assembly of the North American invasive Asteraceae, Tanacetum vulgare (common tansy)

Common tansy (Tanacetum vulgare), a significant agricultural invasive species, threatens forage productivity, livestock carrying capacity, and plant biodiversity across North American agroecosystems. Despite being a close relative to the ornamental Asteraceae Chrysanthemum, T. vulgare genomic studies are severely lacking, but remain critical to the development of novel weed management tools and the investigation of plant invasion evolution. In this study, we performed the assembly and annotation of the diploid genome (2n=2x=18) of an invasive North American T. vulgare genotype using long-read PacBio HiFi and Iso-Seq sequencing technology. The assembled haplotype genome comprised 9 pseudomolecules with a total size of ~4.8 Gb and a scaffold N50 of 546 Mb. In addition, both the plastid and mitochondrial genome sequences were assembled. BUSCO analysis revealed a high overall genome completeness with 69,343 predicted protein-coding genes (AED<0.6: 98%). A high-quality North American invasive reference T. vulgare genome, complementing a recent one assembled for a native European accession, is critical for the investigation of plant invasion biology, genome evolution, and the future development of novel genetic biocontrol weed management technologies.

genomics↗

bioRxiv2026

Functional validation of the Plasmodium falciparum K13 C580Y mutation in recently collected Ethiopian isolates

Recent genomic investigation in Ethiopia identified the first detection of the Plasmodium falciparum kelch13 (K13) C580Y substitution in the Horn of Africa. To assess its functional impact, we introduced C580Y into two recently collected Ethiopian clinical isolates using CRISPR-Cas9 genome editing. Ring-stage survival assays showed significantly elevated in vitro dihydroartemisinin (DHA) survival in edited parasites relative to isogenic controls, demonstrating that C580Y confers artemisinin tolerance in contemporary Ethiopian parasite genetic backgrounds.

microbiology↗

bioRxiv2026

Decoding Ethiopia's unique and structurally divergent Plasmodium falciparum populations using genomics

Previous genome-wide studies suggest that Ethiopian Plasmodium falciparum parasites are unique and structurally divergent from sub-Saharan African populations but were limited by small sample sizes. The emergence of molecular markers associated with reduced artemisinin susceptibility in northern Ethiopia, and the drug pressures created by sympatric P. falciparum and P. vivax, may have fostered a distinct and permissive genetic background for the emergence and spread of multidrug resistant parasites. To characterise parasite population structure and evolutionary dynamics in this setting, we generated whole-genome sequencing data for 163 P. falciparum isolates from southern Ethiopia (2017-2021) and integrated these with 854 isolates from across sub-Saharan Africa. Ethiopian parasites exhibited markedly reduced diversity, highly conserved genomes, and distinct admixture ancestry. Near-fixation of chloroquine and antifolate associated resistance markers, potentially driven by P. vivax co-circulation, suggests persistent drug-related selection pressures. We identified a previously undescribed deletion in the pfmdr1 5' UTR that is common in Ethiopia and potentially widespread across African populations. Although clinically relevant pfk13 variants have emerged in northern Ethiopia, these were not detected in southern Ethiopia. However, strong genetic connectivity between regions indicates the potential for rapid spread of resistance and is therefore important for public health policy and practice.

genomics↗

bioRxiv2024

Iron deprivation activates aboveground cell wall biosynthesis in Populus and the role of PtrbHLH011

Lack of mechanistic understanding of the environmental plasticity of secondary cell wall (SCW) biosynthesis hinders the massive bioenergy production on marginal lands. Growing bioenergy crops on marginal lands is appealing to minimize competition for arable land. However, abiotic stresses, particularly iron deficiency stress, are widespread to perturb SCW biosynthesis. In poplar, a major bioenergy crop, we demonstrated that iron deprivation activates stem SCW biosynthesis and identified transcription factor PtrbHLH011 as a possible underlying regulator. PtrbHLH011 is a potent repressor of SCW, whose overexpression resulted in a reduction of stem SCW by over 65%. Our genomic and molecular studies discovered that PtrbHLH011 binds to the AAAGACA sequence and represses essential genes for SCW biosynthesis, flavonoid biosynthesis, and iron homeostasis. Wood formation and iron deprivation downregulates PtrbHLH011 to release the transcriptional repression. Our findings reveal a regulatory mechanism coordinating SCW biosynthesis in response to environmental iron availability and suggest that PtrbHLH011 manipulation may help engineer bioenergy crops with improved performance under marginal conditions.

plant biology↗

bioRxiv2023

Metagenomic survey of antimicrobial resistance (AMR) in Maryland surface waters differentiated by high and low human impact

In alignment with the One Health paradigm, surface waters are being evaluated as a modality to better understand baseline antimicrobial resistance (AMR) across the environment to supplement existing AMR monitoring in pathogens associated with humans, foods, and animals. Here, we use metagenomic and quasimetagenomic sequence data to describe AMR in Maryland surface waters from developed (high human impact) and natural (low human impact) classifications by the National Land Cover Database (NLCD). Critically important {beta}-lactamase genes were observed in twice as many high human impact zones. All data are available under BioProject PRJNA79347. https://www.ncbi.nlm.nih.gov/bioproject/794347

microbiology↗