Journal Article
Discordant genome assemblies drastically alter the interpretation of single-cell RNA sequencing data which can be mitigated by a novel integration method
Potts, H.G., Lemieux, M.E., Rice, E.S., Warren,W., Choudhury, R.P. and Mommersteeg, M.T.M.
Record Number:
5991
Year:
2022
Journal:
Cells
Pages:
1-16
Volume:
11, 608
Notes:
Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and
conditions of the Creative Commons Attribution (CC BY) license (https://
creativecommons.org/licenses/by/4.0/).
Abstract:
Abstract: Advances in sequencing and assembly technology have led to the creation of genome
assemblies for a wide variety of non-model organisms. The rapid production and proliferation of
updated, novel assembly versions can create vexing problems for researchers when multiple-genome
assembly versions are available at once, requiring researchers to work with more than one reference
genome. Multiple-genome assemblies are especially problematic for researchers studying the genetic
makeup of individual cells, as single-cell RNA sequencing (scRNAseq) requires sequenced reads
to be mapped and aligned to a single reference genome. Using the Astyanax mexicanus, this study
highlights how the interpretation of a single-cell dataset from the same sample changes when aligned
to its two different available genome assemblies. We found that the number of cells and expressed
genes detected were drastically different when aligning to the different assemblies. When the genome
assemblies were used in isolation with their respective annotations, cell-type identification was
confounded, as some classic cell-type markers were assembly-specific, whilst other genes showed
differential patterns of expression between the two assemblies. To overcome the problems posed by
multiple-genome assemblies, we propose that researchers align to each available assembly and then
integrate the resultant datasets to produce a final dataset in which all genome alignments can be used
simultaneously. We found that this approach increased the accuracy of cell-type identification and
maximised the amount of data that could be extracted from our single-cell sample by capturing all
possible cells and transcripts. As scRNAseq becomes more widely available, it is imperative that the
single-cell community is aware of how genome assembly alignment can alter single-cell data and
their interpretation, especially when reviewing studies on non-model organisms.
Keywords: genome assembly; Astyanax mexicanus; integration; seurat; read alignment; non-model
organisms; scRNAseq
Times Cited:
1
Relevent Species: