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Onizuka, M.

Publications and source records attributed to Onizuka, M..

2 recordsLinked to original sources

SC-JNMF: Single-cell clustering integrating multiple quantification methods based on joint non-negative matrix factorization

AO_SCPLOWBSTRACTC_SCPLOWUnsupervised cell clustering is important in discovering cell diversity and subpopulations. Single-cell clustering using gene expression profiles is known to show different results depending on the method of expression quantification; nevertheless, most single-cell clustering methods do not consider the method. In this article, we propose a robust and highly accurate clustering method using joint non-negative matrix factorization (joint NMF) based on multiple gene expression profiles quantified using different methods. Matrix factorization is an excellent method for dimension reduction and feature extraction of data. In particular, NMF approximates the data matrix as the product of two matrices in which all factors are non-negative. Our joint NMF can extract common factors among multiple gene expression profiles by applying each NMF to them under the constraint that one of the factorized matrices is shared among the multiple NMFs. The joint NMF determines more robust and accurate cell clustering results by leveraging multiple quantification methods compared to the conventional clustering methods, which uses only a single quantification method. In conclusion, our study showed that our clustering method using multiple gene expression profiles is more accurate than other popular methods.

bioinformatics↗

Combining single-cell RNA-sequencing with a molecular atlas unveils new markers for C. elegans neuron classes.

Single-cell RNA-sequencing (scRNA-seq) of the Caenorhabditis elegans (C. elegans) nervous system offers the unique opportunity to obtain a partial expression profile for each neuron within a known connectome. Building on recent scRNA-seq data [1] and on a molecular atlas describing the expression pattern of ~800 genes at the single cell resolution [2], we designed an iterative clustering analysis aiming to match each cell-cluster to the ~100 anatomically defined neuron classes of C. elegans. This heuristic approach successfully assigned 58 clusters to their corresponding neuron class. Another 11 clusters grouped neuron classes sharing close molecular signatures and 7 clusters were not assigned. Based on these 76 molecular profiles, we designed 15 new neuron class-specific promoters validated in vivo. Amongst them, 10 represent the only specific promoter reported to this day, expanding the list of neurons amenable to genetic manipulations. Finally, we observed a differential expression of functionally relevant genes between sensory-, inter-, and motor neurons in C. elegans, suggesting the mode of functional diversification may vary accordingly to the neuronal modalities.

genetics↗