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Biology subjects

Parada, G.

Publications and source records attributed to Parada, G..

4 recordsLinked to original sources

Mining alternative splicing patterns in scRNA-seq data using scASfind

Single-cell RNA-seq is widely used for transcriptome profiling, but most analyses have focused on gene-level events, with much less attention devoted to alternative splicing. Here, we present scASfind, a novel computational method to allow for quantitative analysis of cell type-specific splicing events. scASfind utilizes an efficient data structure to store the percent spliced-in value for each splicing event. This makes it possible to exhaustively search for patterns among all differential splicing events, allowing us to identify marker events, mutually exclusive events, and large blocks of exons that are specific to one or more cell types. These methods allow researchers to compare cells based on isoforms rather than genes, thereby enabling more nuanced characterization of cell types and states. We demonstrate the advantages of scASfind on two mouse and one human datasets, identifying differences across the several key genes that cannot be detected using gene expression alone.

bioinformatics↗

Droplet-based Single-cell Total RNA-seq Reveals Differential Non-Coding Expression and Splicing Patterns during Mouse Development

In recent years, single-cell transcriptome sequencing has revolutionized biology, allowing for the unbiased characterization of cellular subpopulations. However, most methods amplify the termini of polyadenylated transcripts capturing only a small fraction of the total cellular transcriptome. This precludes the detection of many long non-coding, short non-coding and non-polyadenylated protein-coding transcripts. Additionally, most workflows do not sequence the full transcript hindering the analysis of alternative splicing. We therefore developed VASA-seq to detect the total transcriptome in single cells. VASA-seq is compatible with both plate-based formats and droplet microfluidics. We applied VASA-seq to over 30,000 single cells in the developing mouse embryo during gastrulation and early organogenesis. The dynamics of the total single-cell transcriptome result in the discovery of novel cell type markers many based on non-coding RNA, an in vivo cell cycle analysis and an improved RNA velocity characterization. Moreover, it provides the first comprehensive analysis of alternative splicing during mammalian development.

molecular biology↗

Bioinformatics approach reveals Nur77-regulated genes common to the central nervous and immune systems

Neurons and immune cells have similar mechanisms for cell to cell communication. Exists active crosstalk between neurons and immune cells. Neurotransmitters can activate or inhibit immune cells, and cytokines modulate neuronal activity. The transcription factor Nur77 (NR4A1) is highly and transiently induced by several stimuli in neurons and T-lymphocytes, suggesting that Nur77 is involved in the coordination of the genetics response in both cell types. By analyzing publicly available databases, we found Nur77 target genes common to the nervous and immune systems. Functions as cell adhesion and anchoring appear as processes regulated by Nur77 in neurons and immune cells.

neuroscience↗

High stretchability, strength and toughness of living cells enabled by hyperelastic vimentin network

In many normal and abnormal physiological processes, including cellular migration during normal development and invasion in cancer metastasis, cells are required to withstand severe deformations. The structural integrity of eukaryotic cells under small deformations has been known to depend on the cytoskeleton including actin filaments (F-actin), microtubules and intermediate filaments (IFs). However, it remains unclear how cells resist severe deformations since both F-actin and microtubules fluidize or disassemble under moderate strains. Here, we demonstrate that vimentin intermediate filaments (VIFs), a marker of mesenchymal cells, dominate cytoplasmic mechanics at large deformations. Our results show that cytoskeletal VIFs form a stretchable, hyperelastic network. This network works synergistically with other dissipative cytoplasmic components, substantially enhancing the strength, stretchability, resilience and toughness of the living cytoplasm.

biophysics↗