Biology subjects

Wassie, A. T.

Publications and source records attributed to Wassie, A. T..

5 recordsLinked to original sources

bioRxiv2025

Prevalence and risk factors of ovine and caprine fasciolosis in Ethiopia: a systematic review and meta-analysis

BackgroundFasciolosis is a parasitic disease caused by liver flukes of the genus Fasciola, predominantly Fasciola hepatica and Fasciola gigantica. This zoonotic disease significantly impacts both livestock and human populations, particularly in areas with extensive agriculture and poor sanitation. Ethiopia, one of the Africas leading ovine and caprine producers, is highly affected by fasciolosis. However, despite its economic and public health importance, there is a lack of comprehensive up-to-date evidence on prevalence and risk factors of small ruminant fasciolosis. Therefore, this systematic review and meta-analysis aims to explore the pooled prevalence of fasciolosis among small ruminants (ovine and caprine) in Ethiopia. MethodsThis systematic review and meta-analysis were conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive systematic review was performed across five electronic databases (Google Scholar, Embase, PubMed, Web of Science, and ScienceDirect), with all database searches and registers inquiries finalized on November 26, 2024. A random-effect model was used to determine the pooled prevalence of fasciolosis in ovine and caprine. Heterogeneity was assessed, and the source of variation was analyzed using subgroup and sensitivity analysis. Publication bias assessment and meta-regression analysis were also performed to ensure the robustness of the review. Funnel plots and Eggers asymmetry tests were used to investigate publication bias. ResultsOverall, 33 studies were included in the meta-analysis, and the pooled prevalence of fasciolosis in ovine and caprine was 32.25% (95% CI: 25.97-38.86%). This study revealed substantial between-study heterogeneity (inconsistency index (I2)) = 97.3%, p < 0.0001). Among the variables analyzed for heterogeneity, species, publication years, season of data collection, and regions of the study were the most significant predictors of heterogeneity The sub-group analysis showed that the prevalence of fasciolosis among ovine and caprine was 37.18% (95% CI; 31.06-43.51%) and 12.76% (95% CI; 4.06-25.19%), respectively. According to the region-based subgroup meta-analysis, studies taken from Amhara region had the highest prevalence of fasciolosis among small ruminants (43.99% (95% CI: 31.83-56.52%)). ConclusionThis systematic review and meta-analysis emphasize fasciolosis as a pervasive threat to Ethiopian small ruminants. Policymakers, healthcare providers, and communities should collaborate to integrate robust prevention mechanisms for the disease, establishing standardized protocols for Fasciola monitoring, reporting, and mitigation.

scientific communication and education↗

bioRxiv2022

Expansion Sequencing of RNA Barcoded Neurons in the Mammalian Brain: Progress and Implications for Molecularly Annotated Connectomics

Mapping and molecularly annotating mammalian neural circuits is challenging due to the inability to uniquely label cells while also resolving subcellular features such as synaptic proteins or fine cellular processes. We argue that an ideal technology for connectomics would have the following characteristics: the capacity for robust distance-independent labeling, synaptic resolution, molecular interrogation, and scalable computational methods. The recent development of high-diversity cellular barcoding with RNA has provided a way to overcome the labeling limitations associated with spectral dyes, however performing all-optical circuit mapping has not been demonstrated because no method exists to image barcodes throughout cells at synaptic-resolution. Here we show ExBarSeq, an integrated method combining in situ sequencing of RNA barcodes, immunostaining, and Expansion Microscopy coupled with an end-to-end software pipeline that automatically extracts barcode identities from large imaging datasets without data processing bottlenecks. As a proof of concept, we applied ExBarSeq to thick tissue sections from mice virally infected with MAPseq viral vectors and demonstrated the extraction of 50 barcoded cells in the visual cortex as well as cell morphologies uncovered via immunostaining. The current work demonstrates high resolution multiplexing of exogenous barcodes and endogenous synaptic proteins and outlines a roadmap for molecularly annotated connectomics at a brain-wide scale.

neuroscience↗

bioRxiv2020

Expansion Revealing: Decrowding Proteins to Unmask Invisible Brain Nanostructures

Cells and tissues are made out of nanoscale building blocks, such as proteins, organized in crowded nanostructures. We show that many biomolecules, and the nanostructures in which they are embedded, may be invisible to prior imaging techniques, due to the inaccessibility of labels (e.g., antibodies) to biomolecules embedded within such crowded structures. We developed a technology, expansion revealing (ExR), which isotropically decrowds proteins from each other, to enable their labeling. We use ExR to discover the alignment of presynaptic calcium channels with postsynaptic machinery in intact brain circuits, as well as the existence of periodic amyloid nanoclusters containing ion channel proteins in Alzheimers model mice. Thus, ExR reveals nanostructures within complex biological specimens that were not previously visualizable, and may find broad use in biology. One Sentence SummaryDe-crowding biomolecules with Expansion Revealing unmasks fundamentally new nanostructures in intact brain tissue, which remained invisible otherwise.

bioengineering↗

bioRxiv2020

The spatial distributions of pre-mRNAs suggest post-transcriptional splicing of specific introns within endogenous genes

Splicing is the stepwise molecular process by which introns are removed from pre-mRNA and exons are joined together to form mature mRNA sequences. The ordering and spatial distribution of these steps remain controversial, with opposing models suggesting splicing occurs either during or after transcription. We used single-molecule RNA FISH, expansion microscopy, and live-cell imaging to reveal the spatiotemporal distribution of nascent transcripts in mammalian cells. At super-resolution levels, we found that pre-mRNA formed clouds around the transcription site. These clouds indicate the existence of a transcription site proximal zone through which RNA move more slowly than in the nucleoplasm. Full-length pre-mRNA undergo continuous splicing as they move through this zone following transcription, suggesting a model in which splicing can occur post-transcriptionally but still within the proximity of the transcription site, thus seeming co-transcriptional by most assays. These results may unify conflicting reports of co-transcriptional versus post-transcriptional splicing.

cell biology↗

bioRxiv2018

Barcoded oligonucleotides ligated on RNA amplified for multiplex and parallel in-situ analyses

We present Barcoded Oligonucleotides Ligated On RNA Amplified for Multiplexed and parallel In-Situ analysis (BOLORAMIS), a reverse-transcription (RT)-free method for spatially-resolved, targeted, in-situ RNA identification of single or multiple targets. For this proof of concept, we have profiled 154 distinct coding and small non-coding transcripts ranging in sizes 18 nucleotides in length and upwards, from over 200, 000 individual human induced pluripotent stem cells (iPSC) and demonstrated compatibility with multiplexed detection, enabled by fluorescent in-situ sequencing. We use BOLORAMIS data to identify differences in spatial localization and cell-to-cell expression heterogeneity. Our results demonstrate BOLORAMIS to be a generalizable toolset for targeted, in-situ detection of coding and small non-coding RNA for single or multiplexed applications.

cell biology↗