Biology subjects

Yoo, D.

Publications and source records attributed to Yoo, D..

4 recordsLinked to original sources

bioRxiv2022

A TMT-based quantitative proteomics approach toward α-syn PFF associated Lewy Body Dementia (LBD) using α-syn PFF-injected mouse brain tissues

The aggregation of -synuclein in the nervous system leads to a class of neurodegenerative disorders termed -synucleinopathies. A form of primary degenerative dementia called Lewy body dementia (LBD) often develops in the case these aggregations develop into intracellular inclusions called Lewy bodies (LB) and Lewy neurites (LN). Despite the high frequency of LBD, being the leading cause of dementia following Alzheimers disease (AD), there is relatively little information discovered about its pathological pathway or diagnostic criteria. In this report, we attempt to address such shortcomings via utilizing a proteomic approach to identify the proteomic changes following intrastriatal injection of -synuclein preformed fibril (-syn PFF). Through mass spectrometry, we have identified a total of 179 proteins that were either up- or down-regulated at different time points, with the four proteins - TPP3, RAB10, CAMK2A, and DYNLL1 - displaying the most significant changes throughout the timeframe. Further examining the modulated proteins with network-based enrichment analyses, we have found that 1) the most significantly associated neurodegenerative pathways were Parkinsons (pV = 3.0e-16) and Huntingtons (pV = 1.9e-15) disease, and 2) the majority of molecular functions specific to the pathology only appeared at later time points. While these results do not expose a conclusive biomarker for LBD, they suggest a potential framework that may be utilized to diagnose and differentiate LBD pathology from other forms of dementia by focusing on the cortical proteomic changes which occur in a later time span.

cell biology↗

bioRxiv2022

Little skate genome exposes the gene regulatory mechanisms underlying the evolution of vertebrate locomotion

The little skate Leucoraja erinacea, a cartilaginous fish, displays pelvic fin driven walking-like behaviors using genetic programs and neuronal subtypes similar to those of land vertebrates. However, mechanistic studies on little skate motor circuit development have been limited, due to a lack of high-quality reference genome. Here, we generated an assembly of the little skate genome, containing precise gene annotation and structures, which allowed post-genome analysis of spinal motor neurons (MNs) essential for locomotion. Through interspecies comparison of mouse, skate and chicken MN transcriptomes, shared and divergent MN expression profiles were identified. Conserved MN genes were enriched for early-stage nervous system development. Comparison of accessible chromatin regions between mouse and skate MNs revealed conservation of the potential regulators with divergent transcription factor (TF) networks through which expression of MN genes is differentially regulated. TF networks in little skate MNs are much simpler than those in mouse MNs, suggesting a more fine-grained control of gene expression operates in mouse MNs. These findings suggest conserved and divergent mechanisms controlling MN development system of vertebrates during evolution and the contribution of intricate gene regulatory networks in the emergence of sophisticated motor system in tetrapods.

evolutionary biology↗

bioRxiv2021

False gene and chromosome losses affected by assembly and sequence errors

Many genome assemblies have been found to be incomplete and contain misassemblies. The Vertebrate Genomes Project (VGP) has been producing assemblies with an emphasis on being as complete and error-free as possible, utilizing long reads, long-range scaffolding data, new assembly algorithms, and manual curation. Here we evaluate these new vertebrate genome assemblies relative to the previous references for the same species, including a mammal (platypus), two birds (zebra finch, Annas hummingbird), and a fish (climbing perch). We found that 3 to 11% of genomic sequence was entirely missing in the previous reference assemblies, which included nearly entire GC-rich and repeat-rich microchromosomes with high gene density. Genome-wide, between 25 to 60% of the genes were either completely or partially missing in the previous assemblies, and this was in part due to a bias in GC-rich 5-proximal promoters and 5 exon regions. Our findings reveal novel regulatory landscapes and protein coding sequences that have been greatly underestimated in previous assemblies and are now present in the VGP assemblies.

genomics↗

bioRxiv2021

Widespread false gene gains caused by duplication errors in genome assemblies

False duplications in genome assemblies lead to false biological conclusions. We quantified false duplications in previous genome assemblies and their new counterparts of the same species (platypus, zebra finch, Annas hummingbird) generated by the Vertebrate Genomes Project (VGP). Whole genome alignments revealed that 4 to 16% of the sequences were falsely duplicated in the previous assemblies, impacting hundreds to thousands of genes. These led to overestimated gene family expansions. The main source of the false duplications was heterotype duplications, where the haplotype sequences were more divergent than other parts of the genome leading the assembly algorithms to classify them as separate genes or genomic regions. A minor source was sequencing errors. Although present in a smaller proportion, we observed false duplications remaining in the VGP assemblies that can be identified and purged. This study highlights the need for more advanced assembly methods that better separates haplotypes and sequence errors, and the need for cautious analyses on gene gains.

genomics↗