diff --git a/joss.04265/10.21105.joss.04265.crossref.xml b/joss.04265/10.21105.joss.04265.crossref.xml
new file mode 100644
index 0000000000..212dfc82c6
--- /dev/null
+++ b/joss.04265/10.21105.joss.04265.crossref.xml
@@ -0,0 +1,238 @@
+
+
+
+ 20220601T054500-ff49e188793b57116d9f56a318ada3d2a0e7ed94
+ 20220601054500
+
+ JOSS Admin
+ admin@theoj.org
+
+ The Open Journal
+
+
+
+
+ Journal of Open Source Software
+ JOSS
+ 2475-9066
+
+ 10.21105/joss
+ https://joss.theoj.org/
+
+
+
+
+ 06
+ 2022
+
+
+ 7
+
+ 74
+
+
+
+ MitoHEAR: an R package for the estimation and
+downstream statistical analysis of the mitochondrial DNA heteroplasmy
+calculated from single-cell datasets
+
+
+
+ Gabriele
+ Lubatti
+
+
+ Elmir
+ Mahammadov
+
+
+ Antonio
+ Scialdone
+
+
+
+ 06
+ 01
+ 2022
+
+
+ 4265
+
+
+ 10.21105/joss.04265
+
+
+ http://creativecommons.org/licenses/by/4.0/
+ http://creativecommons.org/licenses/by/4.0/
+ http://creativecommons.org/licenses/by/4.0/
+
+
+
+ Software archive
+ 10.5281/zenodo.6598821
+
+
+ GitHub review issue
+ https://github.com/openjournals/joss-reviews/issues/4265
+
+
+
+ 10.21105/joss.04265
+ https://joss.theoj.org/papers/10.21105/joss.04265
+
+
+ https://joss.theoj.org/papers/10.21105/joss.04265.pdf
+
+
+
+
+
+ Mitochondrial variant enrichment from
+high-throughput single-cell RNA-seq resolves clonal
+populations
+ Miller
+ Nature Biotechnology
+ 10.1038/s41587-022-01210-8
+ 2022
+ Miller, T. E., Lareau, C. A., Verga,
+J. A., Ssozi, D., Ludwig, L. S., Farran, C. E., Griffin, G. K., Lane, A.
+A., Bernstein, B. E., Sankaran, V. G., & van Galen, P. (2022).
+Mitochondrial variant enrichment from high-throughput single-cell
+RNA-seq resolves clonal populations. Nature Biotechnology.
+https://doi.org/10.1038/s41587-022-01210-8
+
+
+ Lineage tracing in humans enabled by
+mitochondrial mutations and single-cell genomics
+ Ludwig
+ Cell
+ 6
+ 176
+ 10.1016/j.cell.2019.01.022
+ 0092-8674
+ 2019
+ Ludwig, L. S., Lareau, C. A.,
+Ulirsch, J. C., Christian, E., Muus, C., Li, L. H., Pelka, K., Ge, W.,
+Oren, Y., Brack, A., Law, T., Rodman, C., Chen, J. H., Boland, G. M.,
+Hacohen, N., Rozenblatt-Rosen, O., Aryee, M. J., Buenrostro, J. D.,
+Regev, A., & Sankaran, V. G. (2019). Lineage tracing in humans
+enabled by mitochondrial mutations and single-cell genomics. Cell,
+176(6), 1325–1339.e22.
+https://doi.org/10.1016/j.cell.2019.01.022
+
+
+ Cellsnp-lite: an efficient tool for
+genotyping single cells
+ Huang
+ Bioinformatics
+ 10.1093/bioinformatics/btab358
+ 1367-4803
+ 2021
+ Huang, X., & Huang, Y. (2021).
+Cellsnp-lite: an efficient tool for genotyping single cells.
+Bioinformatics.
+https://doi.org/10.1093/bioinformatics/btab358
+
+
+ SCReadCounts: Estimation of cell-level SNVs
+expression from scRNA-seq data
+ Prashant
+ BMC Genomics
+ 10.1186/s12864-021-07974-8
+ 2021
+ Prashant, N., Alomran, N., Chen, Y.,
+Liu, H., Bousounis, P., Movassagh, M., Edwards, N., & Horvath, A.
+(2021). SCReadCounts: Estimation of cell-level SNVs expression from
+scRNA-seq data. BMC Genomics.
+https://doi.org/10.1186/s12864-021-07974-8
+
+
+ Cell competition acts as a purifying
+selection to eliminate cells with mitochondrial defects during early
+mouse development
+ Lima
+ Nature Metabolism
+ 10.1038/s42255-021-00422-7
+ 2021
+ Lima, A., Lubatti, G., Burgstaller,
+J., Hu, D., Green, A., Gregorio, A. D., Zawadzki, T., Pernaute, B.,
+Mahammadov, E., Dore, M., Sanchez, J. M., Bowling, S., Sancho, M.,
+Karimi, M., Carling, D., Jones, N., Srinivas, S., Scialdone, A., &
+Rodriguez, T. A. (2021). Cell competition acts as a purifying selection
+to eliminate cells with mitochondrial defects during early mouse
+development. Nature Metabolism.
+https://doi.org/10.1038/s42255-021-00422-7
+
+
+ Mitochondrial DNA heteroplasmy in disease and
+targeted nuclease-based therapeutic approaches
+ Nissanka
+ EMBO Reports
+ 3
+ 21
+ 10.15252/embr.201949612
+ 2020
+ Nissanka, N., & Moraes, C. T.
+(2020). Mitochondrial DNA heteroplasmy in disease and targeted
+nuclease-based therapeutic approaches. EMBO Reports, 21(3), e49612.
+https://doi.org/10.15252/embr.201949612
+
+
+ The dynamics of mitochondrial DNA
+heteroplasmy: Implications for human health and disease
+ Stewart
+ Nature Reviews Genetics
+ 10.1038/nrg3966
+ 2015
+ Stewart, J., & Chinnery, P.
+(2015). The dynamics of mitochondrial DNA heteroplasmy: Implications for
+human health and disease. Nature Reviews Genetics.
+https://doi.org/10.1038/nrg3966
+
+
+ Segregation of mitochondrial DNA heteroplasmy
+through a developmental genetic bottleneck in human
+embryos
+ Floros
+ Nature Cell Biology
+ 10.1038/s41556-017-0017-8
+ 2019
+ Floros, V., Pyle, A., Dietmann, S.,
+Wei, W., Tang, W., Irie, N., Payne, B., Capalbo, A., Noli, L., Coxhead,
+J., Hudson, G., Crosier, M., Strahl, H., Khalaf, Y., Saitou, M., Ilic,
+D., Surani, M., & Chinnery, P. (2019). Segregation of mitochondrial
+DNA heteroplasmy through a developmental genetic bottleneck in human
+embryos. Nature Cell Biology.
+https://doi.org/10.1038/s41556-017-0017-8
+
+
+ MToolBox: a highly automated pipeline for
+heteroplasmy annotation and prioritization analysis of human
+mitochondrial variants in high-throughput sequencing
+ Calabrese
+ Bioinformatics
+ 21
+ 30
+ 10.1093/bioinformatics/btu483
+ 1367-4803
+ 2014
+ Calabrese, C., Simone, D., Diroma, M.
+A., Santorsola, M., Guttà, C., Gasparre, G., Picardi, E., Pesole, G.,
+& Attimonelli, M. (2014). MToolBox: a highly automated pipeline for
+heteroplasmy annotation and prioritization analysis of human
+mitochondrial variants in high-throughput sequencing. Bioinformatics,
+30(21), 3115–3117.
+https://doi.org/10.1093/bioinformatics/btu483
+
+
+
+
+
+
diff --git a/joss.04265/10.21105.joss.04265.jats b/joss.04265/10.21105.joss.04265.jats
new file mode 100644
index 0000000000..70bbd932cb
--- /dev/null
+++ b/joss.04265/10.21105.joss.04265.jats
@@ -0,0 +1,452 @@
+
+
+
+
+
+
+
+Journal of Open Source Software
+JOSS
+
+2475-9066
+
+Open Journals
+
+
+
+4265
+10.21105/joss.04265
+
+MitoHEAR: an R package for the estimation and downstream
+statistical analysis of the mitochondrial DNA heteroplasmy calculated
+from single-cell datasets
+
+
+
+
+Lubatti
+Gabriele
+
+
+
+
+
+
+
+Mahammadov
+Elmir
+
+
+
+
+
+
+
+Scialdone
+Antonio
+
+
+
+
+*
+
+
+
+Institute of Epigenetics and Stem Cells, Helmholtz Zentrum
+München, Munich, Germany
+
+
+
+
+Institute of Functional Epigenetics, Helmholtz Zentrum
+München, Neuherberg, Germany
+
+
+
+
+Institute of Computational Biology, Helmholtz Zentrum
+München, Neuherberg, Germany
+
+
+
+
+* E-mail:
+
+
+17
+6
+2021
+
+7
+74
+4265
+
+Authors of papers retain copyright and release the
+work under a Creative Commons Attribution 4.0 International License (CC
+BY 4.0)
+2022
+The article authors
+
+Authors of papers retain copyright and release the work under
+a Creative Commons Attribution 4.0 International License (CC BY
+4.0)
+
+
+
+R
+bioinformatics
+single cell RNA seq
+heteroplasmy
+
+
+
+
+
+ Summary
+
Eukaryotic cells rely on mitochondria, organelles that are equipped
+ with their own DNA (mtDNA) to produce the energy they need. Each cell
+ includes multiple mtDNA copies that are not perfectly identical but
+ have differences in their sequence; such sequence variability is
+ called heteroplasmy. mtDNA heteroplasmy has been associated with
+ diseases
+ (Nissanka
+ & Moraes, 2020), that can affect cellular fitness and have
+ an impact on cellular competition
+ (Lima
+ et al., 2021). Several single-cell sequencing protocols provide
+ the data to estimate mtDNA heteroplasmy, including single-cell
+ DNA-seq, RNA-seq and ATAC-seq, in addition to dedicated protocols like
+ MAESTER
+ (Miller
+ et al., 2022). Here, we provide MitoHEAR (Mitochondrial
+ HEteroplasmy AnalyzeR), a user-friendly software written in R that
+ allows the estimation as well as downstream statistical analysis of
+ the mtDNA heteroplasmy calculated from single-cell datasets. MitoHEAR
+ takes as input BAM files, computes the frequency of each allele and,
+ starting from these, estimates the mtDNA heteroplasmy at each covered
+ position for each cell.
+ The analysis parameters (e.g., the filtering of the mtDNA positions
+ based on read quality and coverage) are easily tuneable. Moreover,
+ statistical tests are available to explore the dependency of the mtDNA
+ heteroplasmy on continuous or discrete cell covariates (e.g., culture
+ conditions, differentiation states, etc), as extensively shown in the
+ detailed tutorials we include.
+
+
+ Statement of need
+
Although mtDNA heteroplasmy has important consequences on human
+ health
+ (Stewart
+ & Chinnery, 2015) and embryonic development
+ (Floros
+ et al., 2019), there are still many open questions on how
+ heteroplasmy affects cells’ ability to function and how cells keep it
+ under control. With the increasing availability of single-cell data,
+ many questions can begin to be answered. Still, it is fundamental to
+ have efficient and streamlined computational tools enabling
+ researchers to estimate and analyse mtDNA heteroplasmy. Existing
+ packages
+ (Calabrese
+ et al., 2014;
+ Huang
+ & Huang, 2021;
+ Prashant
+ et al., 2021) focus only on the first step of quantifying
+ heteroplasmy from BAM files, and do not provide any specific tools for
+ further statistical analyses or plotting. Instead, MitoHEAR covers all
+ steps of the analysis in a unique user-friendly package, with highly
+ customisable functions. Starting from BAM files, MitoHEAR estimates
+ heteroplasmy and offers several options for downstream analyses. For
+ example, statistical tests are provided to investigate the
+ relationship of the mtDNA heteroplasmy with continuous or discrete
+ cell covariates. Moreover, there are plotting functions to visualise
+ heteroplasmy and allele frequencies and to perform hierarchical
+ clustering of cells based on heteroplasmy values.
+
+
+ Key functions
+
The two main functions of MitoHEAR are:
+
+
+
get_raw_counts_allele: a parallelised
+ function that relies on Rsamtools and generates the raw counts
+ matrix starting from BAM files, with cells as rows and bases with
+ the four possible alleles as columns.
+
+
+
get_heteroplasmy: Starting from the
+ output of get_raw_counts_allele, it
+ computes the matrix with heteroplasmy values (defined as 1 minus
+ the frequency of the most common allele) and the matrix with
+ allele frequency values, for all the cells and bases that pass a
+ filtering procedure.
+
+
+
Among the downstream analyses implemented in the package are:
+
+
+
Several statistical tests (e.g., Wilcoxon rank-sum test) for
+ the identification of the mtDNA positions with the most different
+ levels of heteroplasmy between discrete groups of cells or along a
+ trajectory of cells (i.e., cells sorted according to a diffusion
+ pseudo-time) (Figure 1 and Figure
+ 2).
+
+
+
Plotting functions for the visualisation of heteroplasmy and
+ the corresponding allele frequency values among cells.
+
+
+
Unsupervised hierarchical clustering of cells based on a
+ distance matrix defined from the angular distance of allele
+ frequencies that could be relevant for lineage tracing analysis
+ (Ludwig
+ et al., 2019) (Figure 3).
+
+
+
+
Example of an output plot generated by MitoHEAR showing
+ heteroplasmy values at a given position estimated from single cells
+ in three clusters indicated on the x-axis. Data from Lima et al.
+ (2021).
+
+
+
+
+
Example of an output figure generated by MitoHEAR where
+ the heteroplasmy is plotted as a function of the pseudo-time
+ coordinate of each cell. Cells are classified into three clusters.
+ The heteroplasmy shows a statistically significant change along the
+ pseudo-time, as indicated by the adjusted p-value reported at the
+ top, which is computed by a generalised additive model fit. Data
+ from Lima et al.
+ (2021).
+
+
+
+
+
Unsupervised hierarchical clustering of cells based on a
+ distance matrix defined from the angular distance of allele
+ frequencies. The data shown is bulk RNA-seq mouse data from two
+ mtDNA cell lines labelled Loser and
+ Winner. Data from Lima et al.
+ (2021).
+
+
+
+
The package has been used in a recently published paper
+ (Lima
+ et al., 2021), where we revealed that cells with higher levels
+ of heteroplasmy are eliminated by cell competition in mouse embryos
+ and are characterised by specific gene expression patterns.
+
+
+
+
+
+
+
+ MillerTyler E.
+ LareauCaleb A.
+ VergaJulia A.
+ SsoziDaniel
+ LudwigLeif S.
+ FarranChadi El
+ GriffinGabriel K.
+ LaneAndrew A.
+ BernsteinBradley E.
+ SankaranVijay G.
+ van GalenPeter
+
+ Mitochondrial variant enrichment from high-throughput single-cell RNA-seq resolves clonal populations
+ Nature Biotechnology
+ 2022
+ https://www.nature.com/articles/s41587-022-01210-8
+ 10.1038/s41587-022-01210-8
+
+
+
+
+
+ LudwigLeif S.
+ LareauCaleb A.
+ UlirschJacob C.
+ ChristianElena
+ MuusChristoph
+ LiLauren H.
+ PelkaKarin
+ GeWill
+ OrenYaara
+ BrackAlison
+ LawTravis
+ RodmanChristopher
+ ChenJonathan H.
+ BolandGenevieve M.
+ HacohenNir
+ Rozenblatt-RosenOrit
+ AryeeMartin J.
+ BuenrostroJason D.
+ RegevAviv
+ SankaranVijay G.
+
+ Lineage tracing in humans enabled by mitochondrial mutations and single-cell genomics
+ Cell
+ 2019
+ 176
+ 6
+ 0092-8674
+ https://www.sciencedirect.com/science/article/pii/S0092867419300558
+ 10.1016/j.cell.2019.01.022
+ 1325
+ 1339.e22
+
+
+
+
+
+ HuangXianjie
+ HuangYuanhua
+
+ Cellsnp-lite: an efficient tool for genotyping single cells
+ Bioinformatics
+ 202105
+ 1367-4803
+ https://doi.org/10.1093/bioinformatics/btab358
+ 10.1093/bioinformatics/btab358
+
+
+
+
+
+ PrashantNM
+ AlomranNawaf
+ ChenYu
+ LiuHongyu
+ BousounisPavlos
+ MovassaghMercedeh
+ EdwardsNathan
+ HorvathAnelia
+
+ SCReadCounts: Estimation of cell-level SNVs expression from scRNA-seq data
+ BMC Genomics
+ 2021
+ https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-021-07974-8
+ 10.1186/s12864-021-07974-8
+
+
+
+
+
+ LimaAna
+ LubattiGabriele
+ BurgstallerJörg
+ HuDi
+ GreenAlistair
+ GregorioAida Di
+ ZawadzkiTamzin
+ PernauteBarbara
+ MahammadovElmir
+ DoreMarian
+ SanchezJuan Miguel
+ BowlingSarah
+ SanchoMargarida
+ KarimiMohammad
+ CarlingDavid
+ JonesNick
+ SrinivasShankar
+ ScialdoneAntonio
+ RodriguezTristan A.
+
+ Cell competition acts as a purifying selection to eliminate cells with mitochondrial defects during early mouse development
+ Nature Metabolism
+ 2021
+ https://www.nature.com/articles/s42255-021-00422-7
+ 10.1038/s42255-021-00422-7
+
+
+
+
+
+ NissankaNadee
+ MoraesCarlos T
+
+ Mitochondrial DNA heteroplasmy in disease and targeted nuclease-based therapeutic approaches
+ EMBO Reports
+ 2020
+ 21
+ 3
+ https://www.embopress.org/doi/abs/10.15252/embr.201949612
+ 10.15252/embr.201949612
+ e49612
+
+
+
+
+
+
+ StewartJ
+ ChinneryP
+
+ The dynamics of mitochondrial DNA heteroplasmy: Implications for human health and disease
+ Nature Reviews Genetics
+ 2015
+ 10.1038/nrg3966
+
+
+
+
+
+ FlorosVI
+ PyleA
+ DietmannS
+ WeiW
+ TangWCW
+ IrieN
+ PayneB
+ CapalboA
+ NoliL
+ CoxheadJ
+ HudsonG
+ CrosierM
+ StrahlH
+ KhalafY
+ SaitouM
+ IlicD
+ SuraniMA
+ ChinneryPF
+
+ Segregation of mitochondrial DNA heteroplasmy through a developmental genetic bottleneck in human embryos
+ Nature Cell Biology
+ 2019
+ 10.1038/s41556-017-0017-8
+
+
+
+
+
+ CalabreseClaudia
+ SimoneDomenico
+ DiromaMaria Angela
+ SantorsolaMariangela
+ GuttàCristiano
+ GasparreGiuseppe
+ PicardiErnesto
+ PesoleGraziano
+ AttimonelliMarcella
+
+ MToolBox: a highly automated pipeline for heteroplasmy annotation and prioritization analysis of human mitochondrial variants in high-throughput sequencing
+ Bioinformatics
+ 201407
+ 30
+ 21
+ 1367-4803
+ https://doi.org/10.1093/bioinformatics/btu483
+ 10.1093/bioinformatics/btu483
+ 3115
+ 3117
+
+
+
+
+
diff --git a/joss.04265/10.21105.joss.04265.pdf b/joss.04265/10.21105.joss.04265.pdf
new file mode 100644
index 0000000000..ac3dc37ccc
Binary files /dev/null and b/joss.04265/10.21105.joss.04265.pdf differ