Biology subjects

Gebeyehu, S.

Publications and source records attributed to Gebeyehu, S..

2 recordsLinked to original sources

bioRxiv2024

The genome of Przewalski's horse (Equus ferus przewalskii)

The Przewalskis horse (Equus ferus przewalskii) is an endangered equid native to the steppes of central Asia. After becoming extinct in the wild, multiple conservation efforts convened to preserve the species including captive breeding programs, reintroduction and monitoring systems, protected lands, and cloning. Availability of a highly contiguous reference genome is essential to support these continued efforts. We used Oxford Nanopore sequencing to produce a scaffold-level 2.5 Gb nuclear assembly and 16,002 bp mitogenome from a captive Przewalskis mare. All assembly drafts were generated from 111 Gb of sequence from a single PromethION R10.4.1 flow cell. The mitogenome contained 37 genes in the standard mammalian configuration and was 99.63% identical to the domestic horse (Equus caballus). The nuclear assembly, EquPr2, contained 2,146 scaffolds with an N50 of 85.1 Mb, 43X mean depth, and BUSCO quality score of 98.92%. EquPr2 successfully improves upon the existing Przewalskis horse reference genome (Burgud), with 25-fold fewer scaffolds, a 166-fold larger N50, and phased pseudohaplotypes. Modified basecalls revealed 79.5% DNA methylation and 2.1% hydroxymethylation globally. Allele-specific methylation analysis between pseudohaplotypes revealed 226 differentially methylated regions (DMRs) in known imprinted genes and loci not previously reported as imprinted. The heterozygosity rate of 0.165% matches previous estimates for the species and compares favorably to other endangered animals. This improved Przewalskis horse assembly will serve as a valuable resource for conservation efforts and comparative genomics investigations.

genomics↗

bioRxiv2024

Pathogen and pest risks to vegetatively propagated crops in humanitarian contexts: Geographic priorities for Cameroon and Ethiopia

In humanitarian contexts, supporting agricultural recovery after natural or human-driven shocks--and strengthening vulnerable communities through development interventions--is critical when crop and seed shortages threaten food security and livelihoods. Cameroon and Ethiopia face humanitarian crises that disrupt the production of key food security crops like banana and plantain, cassava, potato, and sweetpotato. In this study, we address crop pathogen and pest effects in a humanitarian context, both in general and with a focus on their effects on planting material quality through seed degeneration. We provide the foundation for a national plant health risk analysis to inform regional and national surveillance and management strategies. We analyzed cropland density maps and applied network centrality metrics to identify locations that are candidates for disease and pest management and surveillance in Cameroon and Ethiopia. We used expert knowledge elicitation and global trade data to map pathogen and pest movement risks and characterize trade of crop-specific commodities and planting materials. We identified specific locations that may be important for pathogen and pest spread in Cameroon and Ethiopia, given their roles in the cropland network, and the reported presence of pathogens and pests. These results provide a baseline national plant health risk analysis for Cameroon and Ethiopia. We discuss strategies for ongoing improvement of a national plant health risk analysis, to inform decision-making in the humanitarian sector for designing on-the-ground actions to avoid unintentional spread of pathogens and pests during agricultural recovery interventions.

ecology↗