ScMAPA: Identification of cell-type–specific alternative polyadenylation in complex tissues. (30th April 2022)

• Record Type: Journal Article
• Authors: Bai, Yulong; Qin, Yidi; Fan, Zhenjiang; Morrison, Robert M; Nam, KyongNyon; Zarour, Hassane M; Koldamova, Radosveta; Padiath, Quasar Saleem; Kim, Soyeon; Park, Hyun Jung
• Is Part Of: GigaScience. Volume 11(2022)
• Publication Date: 2022-04-30
• Subjects: post-transcriptional regulation -- alternative polyadenylation -- single-cell RNA -- cell-type–specific regulation -- confounding factors; Information storage and retrieval systems -- Research -- Periodicals; Biology -- Research -- Periodicals; Medical sciences -- Research -- Periodicals; Database management -- Periodicals; 570.285
• DOI: 10.1093/gigascience/giac033
• Languages: English
• ISSNs: 2047-217X

Abstract

Abstract: Background: Alternative polyadenylation (APA) causes shortening or lengthening of the 3ʹ-untranslated region (3ʹ-UTR) of genes (APA genes) in diverse cellular processes such as cell proliferation and differentiation. To identify cell-type–specific APA genes in scRNA-Seq data, current bioinformatic methods have several limitations. First, they assume certain read coverage shapes in the scRNA-Seq data, which can be violated in multiple APA genes. Second, their identification is limited between 2 cell types and not directly applicable to the data of multiple cell types. Third, they do not control undesired source of variance, which potentially introduces noise to the cell-type–specific identification of APA genes. Findings: We developed a combination of a computational change-point algorithm and a statistical model, single-cell Multi-group identification of APA (scMAPA). To avoid the assumptions on the read coverage shape, scMAPA formulates a change-point problem after transforming the 3ʹ biased scRNA-Seq data to represent the full-length 3ʹ-UTR signal. To identify cell-type–specific APA genes while adjusting for undesired source of variation, scMAPA models APA isoforms in consideration of the cell types and the undesired source. In our novel simulation data and data from human peripheral blood mononuclear cells, scMAPA outperforms existing methods in sensitivity, robustness, and stability. In mouse brain data consisting of multiple cell types sampled from multiple regions, scMAPA identifies cell-type–specific APA genes, elucidating novel roles of APA for dividing immune cells and differentiated neuron cells and in multiple brain disorders. Conclusions: scMAPA elucidates the cell-type–specific function of APA events and sheds novel insights into the functional roles of APA events in complex tissues.