Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Cell competition acts as a purifying selection to eliminate cells with mitochondrial defects during early mouse development

Abstract

Cell competition is emerging as a quality-control mechanism that eliminates unfit cells in a wide range of settings from development to the adult. However, the nature of the cells normally eliminated by cell competition and what triggers their elimination remains poorly understood. In mice, 35% of epiblast cells are eliminated before gastrulation. Here we show that cells with mitochondrial defects are eliminated by cell competition during early mouse development. Using single-cell transcriptional profiling of eliminated mouse epiblast cells, we identify hallmarks of cell competition and mitochondrial defects. We demonstrate that mitochondrial defects are common to a range of different loser cell types and that manipulating mitochondrial function triggers cell competition. Moreover, we show that in the mouse embryo, cell competition eliminates cells with sequence changes in mt-Rnr1 and mt-Rnr2, and that even non-pathological changes in mitochondrial DNA sequences can induce cell competition. Our results suggest that cell competition is a purifying selection that optimizes mitochondrial performance before gastrulation.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Cells eliminated during early mouse embryogenesis have a distinct transcriptional profile.
Fig. 2: A cell competition transcriptional signature is identified in cells eliminated during mouse embryonic development.
Fig. 3: Cells eliminated during early mouse embryogenesis have mitochondrial defects.
Fig. 4: Mitochondrial defects are a common feature of cells eliminated by cell competition.
Fig. 5: Manipulating mitochondria biology is sufficient to trigger cell competition.
Fig. 6: Intermediate and loser epiblast cells accumulate polymorphisms in mtDNA sequences.
Fig. 7: Changes in mtDNA sequence can determine the competitive ability of a cell.
Fig. 8: Model of cell competition.

Similar content being viewed by others

Data availability

Data were analysed with standard programmes and packages, as detailed above. All relevant data are included in the paper and/or its Supplementary Information files. RNA-seq raw data as well as processed data are available through ArrayExpress, under accession numbers E-MTAB-8640, for scRNA-seq data, and E-MTAB-8692, for bulk RNA-seq data. Source data are provided with this paper.

Code availability

Code used to generate the figures in the paper is available at https://github.com/ScialdoneLab/Cell-Competition-Paper-Figures/.

References

  1. Bowling, S., Lawlor, K. & Rodriguez, T. A. Cell competition: the winners and losers of fitness selection. Development 146, dev167486 (2019).

    Article  CAS  PubMed  Google Scholar 

  2. Diaz-Diaz, C. & Torres, M. Insights into the quantitative and dynamic aspects of cell competition. Curr. Opin. Cell Biol. 60, 68–74 (2019).

    Article  CAS  PubMed  Google Scholar 

  3. Madan, E., Gogna, R. & Moreno, E. Cell competition in development: information from flies and vertebrates. Curr. Opin. Cell Biol. 55, 150–157 (2018).

    Article  CAS  PubMed  Google Scholar 

  4. Morata, G. & Ripoll, P. Minutes: mutants of Drosophila autonomously affecting cell division rate. Dev. Biol. 42, 211–221 (1975).

    Article  CAS  PubMed  Google Scholar 

  5. Claveria, C., Giovinazzo, G., Sierra, R. & Torres, M. Myc-driven endogenous cell competition in the early mammalian embryo. Nature 500, 39–44 (2013).

    Article  CAS  PubMed  Google Scholar 

  6. Sancho, M. et al. Competitive interactions eliminate unfit embryonic stem cells at the onset of differentiation. Dev. Cell 26, 19–30 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Bowling, S. et al. P53 and mTOR signalling determine fitness selection through cell competition during early mouse embryonic development. Nat. Commun. 9, 1763 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  8. Diaz-Diaz, C. et al. Pluripotency surveillance by myc-driven competitive elimination of differentiating cells. Dev. Cell 42, 585–599 (2017).

    Article  CAS  PubMed  Google Scholar 

  9. Hashimoto, M. & Sasaki, H. Epiblast formation by TEAD-YAP-dependent expression of pluripotency factors and competitive elimination of unspecified cells. Dev. Cell 50, 139–154 (2019).

    Article  CAS  PubMed  Google Scholar 

  10. Lima, A., Burgstaller, J., Sanchez-Nieto, J. M. & Rodriguez, T. A. The mitochondria and the regulation of cell fitness during early mammalian development. Curr. Top. Dev. Biol. 128, 339–363 (2018).

    Article  CAS  PubMed  Google Scholar 

  11. Zhou, W. et al. HIF1α induced switch from bivalent to exclusively glycolytic metabolism during ESC-to-EpiSC/hESC transition. EMBO J. 31, 2103–2116 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Khrapko, K. et al. Mitochondrial mutational spectra in human cells and tissues. Proc. Natl Acad. Sci. USA 94, 13798–13803 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  13. Allio, R., Donega, S., Galtier, N. & Nabholz, B. Large variation in the ratio of mitochondrial to nuclear mutation rate across animals: implications for genetic diversity and the use of mitochondrial DNA as a molecular marker. Mol. Biol. Evol. 34, 2762–2772 (2017).

    Article  CAS  PubMed  Google Scholar 

  14. Burgstaller, J. P., Johnston, I. G. & Poulton, J. Mitochondrial DNA disease and developmental implications for reproductive strategies. Mol. Hum. Reprod. 21, 11–22 (2015).

    Article  CAS  PubMed  Google Scholar 

  15. Gorman, G. S. et al. Mitochondrial diseases. Nat. Rev. Dis. Prim. 2, 16080 (2016).

    Article  PubMed  Google Scholar 

  16. Burgstaller, J. P. et al. MtDNA segregation in heteroplasmic tissues is common in vivo and modulated by haplotype differences and developmental stage. Cell Rep. 7, 2031–2041 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Johnston, I. G. et al. Stochastic modelling, Bayesian inference, and new in vivo measurements elucidate the debated mtDNA bottleneck mechanism. eLife 4, e07464 (2015).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  18. Latorre-Pellicer, A. et al. Regulation of mother-to-offspring transmission of mtDNA heteroplasmy. Cell Metab. 30, 1120–1130 (2019).

  19. Lee, H. S. et al. Rapid mitochondrial DNA segregation in primate preimplantation embryos precedes somatic and germline bottleneck. Cell Rep. 1, 506–515 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Zhang, H., Burr, S. P. & Chinnery, P. F. The mitochondrial DNA genetic bottleneck: inheritance and beyond. Essays Biochem. 62, 225–234 (2018).

    Article  PubMed  Google Scholar 

  21. Sharpley, M. S. et al. Heteroplasmy of mouse mtDNA is genetically unstable and results in altered behavior and cognition. Cell 151, 333–343 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Wolf, F. A. et al. PAGA: graph abstraction reconciles clustering with trajectory inference through a topology preserving map of single cells. Genome Biol. 20, 59 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  23. Angerer, P. et al. destiny: diffusion maps for large-scale single-cell data in R. Bioinformatics 32, 1241–1243 (2016).

    Article  CAS  PubMed  Google Scholar 

  24. Kramer, A., Green, J., Pollard, J. Jr. & Tugendreich, S. Causal analysis approaches in ingenuity pathway analysis. Bioinformatics 30, 523–530 (2014).

    Article  PubMed  CAS  Google Scholar 

  25. Haghverdi, L., Buttner, M., Wolf, F. A., Buettner, F. & Theis, F. J. Diffusion pseudotime robustly reconstructs lineage branching. Nat. Methods 13, 845–848 (2016).

    Article  CAS  PubMed  Google Scholar 

  26. Cheng, S. et al. Single-cell RNA-seq reveals cellular heterogeneity of pluripotency transition and X chromosome dynamics during early mouse development. Cell Rep. 26, 2593–2607 (2019).

    Article  CAS  PubMed  Google Scholar 

  27. Topf, U., Wrobel, L. & Chacinska, A. Chatty mitochondria: keeping balance in cellular protein homeostasis. Trends Cell Biol. 26, 577–586 (2016).

    Article  CAS  PubMed  Google Scholar 

  28. Melber, A. & Haynes, C. M. UPRmt regulation and output: a stress response mediated by mitochondrial–nuclear communication. Cell Res. 28, 281–295 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Munch, C. The different axes of the mammalian mitochondrial unfolded protein response. BMC Biol. 16, 81 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  30. Zhao, Q. et al. A mitochondrial specific stress response in mammalian cells. EMBO J. 21, 4411–4419 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Nargund, A. M., Pellegrino, M. W., Fiorese, C. J., Baker, B. M. & Haynes, C. M. Mitochondrial import efficiency of ATFS-1 regulates mitochondrial UPR activation. Science 337, 587–590 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Quiros, P. M., Mottis, A. & Auwerx, J. Mitonuclear communication in homeostasis and stress. Nat. Rev. Mol. Cell Biol. 17, 213–226 (2016).

    Article  CAS  PubMed  Google Scholar 

  33. Mouchiroud, L. et al. The NAD+/sirtuin pathway modulates longevity through activation of mitochondrial UPR and FOXO signaling. Cell 154, 430–441 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Saveljeva, S. et al. Endoplasmic reticulum stress-mediated induction of SESTRIN 2 potentiates cell survival. Oncotarget 7, 12254–12266 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  35. Yun, J. & Finkel, T. Mitohormesis. Cell Metab. 19, 757–766 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Chen, H. et al. Mitofusins Mfn1 and Mfn2 coordinately regulate mitochondrial fusion and are essential for embryonic development. J. Cell Biol. 160, 189–200 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Prudent, J. & McBride, H. M. The mitochondria–endoplasmic reticulum contact sites: a signalling platform for cell death. Curr. Opin. Cell Biol. 47, 52–63 (2017).

    Article  CAS  PubMed  Google Scholar 

  38. Smirnova, E., Griparic, L., Shurland, D. L. & van der Bliek, A. M. Dynamin-related protein Drp1 is required for mitochondrial division in mammalian cells. Mol. Biol. Cell 12, 2245–2256 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Favaro, G. et al. DRP1-mediated mitochondrial shape controls calcium homeostasis and muscle mass. Nat. Commun. 10, 2576 (2019).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  40. Quiros, P. M. et al. Multi-omics analysis identifies ATF4 as a key regulator of the mitochondrial stress response in mammals. J. Cell Biol. 216, 2027–2045 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  41. Restelli, L. M. et al. Neuronal mitochondrial dysfunction activates the integrated stress response to induce fibroblast growth factor 21. Cell Rep. 24, 1407–1414 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Richter, U. et al. A mitochondrial ribosomal and RNA decay pathway blocks cell proliferation. Curr. Biol. 23, 535–541 (2013).

    Article  CAS  PubMed  Google Scholar 

  43. Moullan, N. et al. Tetracyclines disturb mitochondrial function across eukaryotic models: a call for caution in biomedical research. Cell Rep. 10, 1681–1691 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Kauppila, J. H. K. et al. A phenotype-driven approach to generate mouse models with pathogenic mtDNA mutations causing mitochondrial disease. Cell Rep. 16, 2980–2990 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. Fan, W. et al. A mouse model of mitochondrial disease reveals germline selection against severe mtDNA mutations. Science 319, 958–962 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  46. Stewart, J. B. et al. Strong purifying selection in transmission of mammalian mitochondrial DNA. PLoS Biol. 6, e10 (2008).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  47. Freyer, C. et al. Variation in germline mtDNA heteroplasmy is determined prenatally but modified during subsequent transmission. Nat. Genet. 44, 1282–1285 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Ludwig, L. S. et al. Lineage tracing in humans enabled by mitochondrial mutations and single-cell genomics. Cell 176, 1325–1339 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  49. Chinnery, P. F. & Hudson, G. Mitochondrial genetics. Br. Med. Bull. 106, 135–159 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Floros, V. I. et al. Segregation of mitochondrial DNA heteroplasmy through a developmental genetic bottleneck in human embryos. Nat. Cell Biol. 20, 144–151 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Burr, S. P., Pezet, M. & Chinnery, P. F. Mitochondrial DNA heteroplasmy and purifying selection in the mammalian female germline. Dev. Growth Differ. 60, 21–32 (2018).

    Article  PubMed  Google Scholar 

  52. Rajasimha, H. K., Chinnery, P. F. & Samuels, D. C. Selection against pathogenic mtDNA mutations in a stem cell population leads to the loss of the 3243 A > G mutation in blood. Am. J. Hum. Genet. 82, 333–343 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  53. Ellis, S. J. et al. Distinct modes of cell competition shape mammalian tissue morphogenesis. Nature 569, 497–502 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Kucinski, I., Dinan, M., Kolahgar, G. & Piddini, E. Chronic activation of JNK JAK/STAT and oxidative stress signalling causes the loser cell status. Nat. Commun. 8, 136 (2017).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  55. Kon, S. et al. Cell competition with normal epithelial cells promotes apical extrusion of transformed cells through metabolic changes. Nat. Cell Biol. 19, 530–541 (2017).

    Article  CAS  PubMed  Google Scholar 

  56. Ran, F. A. et al. Genome engineering using the CRISPR–Cas9 system. Nat. Protoc. 8, 2281–2308 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  57. Czechanski, A. et al. Derivation and characterization of mouse embryonic stem cells from permissive and nonpermissive strains. Nat. Protoc. 9, 559–574 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  58. Burgstaller, J. P. et al. Large-scale genetic analysis reveals mammalian mtDNA heteroplasmy dynamics and variance increase through lifetimes and generations. Nat. Commun. 9, 2488 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  59. Burgstaller, J. P., Schinogl, P., Dinnyes, A., Muller, M. & Steinborn, R. Mitochondrial DNA heteroplasmy in ovine fetuses and sheep cloned by somatic cell nuclear transfer. BMC Dev. Biol. 7, 141 (2007).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  60. Kang, E. et al. Mitochondrial replacement in human oocytes carrying pathogenic mitochondrial DNA mutations. Nature 540, 270–275 (2016).

    Article  CAS  PubMed  Google Scholar 

  61. Yahata, N., Boda, H. & Hata, R. Elimination of mutant mtDNA by an optimized mpTALEN restores differentiation capacities of heteroplasmic MELAS-iPSCs. Mol. Ther. Methods Clin. Dev. 20, 54–68 (2021).

    Article  CAS  PubMed  Google Scholar 

  62. Venegas, V. & Halberg, M.C. Quantification of mtDNA mutation heteroplasmy (ARMS–qPCR). Methods Mol. Biol. 837, 313–326 (2012).

  63. Machado, T. S. et al. Real-time PCR quantification of heteroplasmy in a mouse model with mitochondrial DNA of C57BL/6 and NZB/BINJ strains. PLoS ONE 10, e0133650 (2015).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  64. Schindelin, J. et al. Fiji: an open-source platform for biological-image analysis. Nat. Methods 9, 676–682 (2012).

    Article  CAS  PubMed  Google Scholar 

  65. Kim, D. et al. TopHat2: accurate alignment of transcriptomes in the presence of insertions, deletions and gene fusions. Genome Biol. 14, R36 (2013).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  66. Liao, Y., Smyth, G. K. & Shi, W. The R package Rsubread is easier, faster, cheaper and better for alignment and quantification of RNA sequencing reads. Nucleic Acids Res. 47, e47 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  67. Love, M. I., Huber, W. & Anders, S. Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2. Genome Biol. 15, 550 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  68. Mootha, V. K. et al. PGC-1α-responsive genes involved in oxidative phosphorylation are coordinately downregulated in human diabetes. Nat. Genet. 34, 267–273 (2003).

    Article  CAS  PubMed  Google Scholar 

  69. Subramanian, A. et al. Gene-set enrichment analysis: a knowledge-based approach for interpreting genome-wide expression profiles. Proc. Natl Acad. Sci. USA 102, 15545–15550 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  70. Picelli, S. et al. Smart-seq2 for sensitive full-length transcriptome profiling in single cells. Nat. Methods 10, 1096–1098 (2013).

    Article  CAS  PubMed  Google Scholar 

  71. Patro, R., Duggal, G., Love, M. I., Irizarry, R. A. & Kingsford, C. Salmon provides fast and bias-aware quantification of transcript expression. Nat. Methods 14, 417–419 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  72. Lun, A. T., McCarthy, D. J. & Marioni, J. C. A step-by-step workflow for low-level analysis of single-cell RNA-seq data with Bioconductor. F1000Res 5, 2122 (2016).

    PubMed  PubMed Central  Google Scholar 

  73. Scialdone, A. et al. Resolving early mesoderm diversification through single-cell expression profiling. Nature 535, 289–293 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  74. Wolf, F. A., Angerer, P. & Theis, F. J. SCANPY: large-scale single-cell gene expression data analysis. Genome Biol. 19, 15 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  75. Dobin, A. et al. STAR: ultrafast universal RNA-seq aligner. Bioinformatics 29, 15–21 (2013).

    Article  CAS  PubMed  Google Scholar 

  76. Calabrese, F. M., Simone, D. & Attimonelli, M. Primates and mouse NumtS in the UCSC Genome Browser. BMC Bioinformatics 13, S15 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  77. Lukes, J., Kaur, B. & Speijer, D. RNA editing in mitochondria and plastids: weird and widespread. Trends Genet. 37, 99–102 (2021).

    Article  CAS  PubMed  Google Scholar 

  78. Robinson, M. D., McCarthy, D. J. & Smyth, G. K. edgeR: a Bioconductor package for differential expression analysis of digital gene expression data. Bioinformatics 26, 139–140 (2010).

    Article  CAS  PubMed  Google Scholar 

  79. Reimand, J., Arak, T. & Vilo, J. g:Profiler—a web server for functional interpretation of gene lists (2011 update). Nucleic Acids Res. 39, W307–W315 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  80. Zappia, L. & Oshlack, A. Clustering trees: a visualization for evaluating clusterings at multiple resolutions. GigaScience 7, giy083 (2018).

    Article  PubMed Central  CAS  Google Scholar 

  81. Scialdone, A. et al. Computational assignment of cell-cycle stage from single-cell transcriptome data. Methods 85, 54–61 (2015).

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

We thank S. Rothery for guidance and advice with confocal microscopy. The FILM at Imperial College London is supported in part by funding from the Wellcome Trust (grant no. 104931/Z/14/Z) and BBSRC (grant no. BB/L015129/1). We thank J. Elliot and B. Patel from the LMS/NIHR Imperial Biomedical Research Centre Flow Cytometry Facility for support. We are thankful to G. Chennell and A. Sardini for guidance and support with Seahorse experiments. Research in the laboratory of T.A.R. was supported by the MRC project grant (MR/P018467/1) and the BBSRC project grant (BB/S008284/1) and by the British Heart Foundation (BHF) PhD studentships (FS/14/62/31288 and FS/17/64/33476). Work in the laboratory of A.S. is funded by the Helmholtz Association. A.L. was funded by a BHF centre of excellence PhD studentship. S.S. was funded through Wellcome awards 103788/Z/14/Z and 108438/Z/15/Z.

Author information

Authors and Affiliations

Authors

Contributions

A.L. performed most of the experimental wet-lab work. J.B. and A.L. derived heteroplasmic mESC lines. J.B. performed heteroplasmy measurements in heteroplasmic mESCs. B.P. generated Mfn2/ and Drp1/ mESCs, and J.M.S. conducted characterization of mitochondria shape and pluripotency status. S.P.-M. participated in the metabolic characterization of Drp1/ cells. D.H. performed embryo dissections, treatments and cell dissociation before scRNA-seq experiments. G.L. did the bioinformatic analysis of scRNA-seq data. E.M., N.J. and A.P.G. participated in the analysis of mtDNA heteroplasmy. A.D.G. performed the metabolomic studies using the Metabolon platform and participated in embryo dissections and immunohistochemistry stainings for validation of results obtained by scRNA-seq. T.K. collected the embryos for derivation of the mESCs with different mtDNA content. M.D. and M.K. performed the bioinformatic analysis of bulk RNA-seq experiments. N.J., S.S. and D.C. participated in the design of experimental work and analysis of results. A.L., G.L., A.S and T.A.R. interpreted results and wrote the paper. T.A.R. and A.S. directed and designed the research.

Corresponding authors

Correspondence to Antonio Scialdone or Tristan A. Rodriguez.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Metabolism thanks Anna-Katerina Hadjantonakis and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editors: Christoph Schmitt; Elena Bellafante.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Quality controls of scRNA-seq and clustering robustness analysis.

a, Selection criteria for quality control (QC) of all cells. A total of 723 passed the quality control (723 good quality cells) and were considered for downstream analysis. All these parameters were computed for each cell. Log10 total number of reads (top left): log10 of the sum of the number of reads that were processed in every cell; Fraction of mapped reads (top central): number of reads that are confidentially mapped to the reference genome divided by total number of reads that were processed for each cell. This number is automatically provided by Salmon v0.8.2; Fraction of genes (top right): number of reads mapped to endogenous genes divided by the total sum of reads that were processed; Fraction of mt-genes (bottom left): number of reads mapped to mitochondrial genes divided by the total sum of reads that were processed; Fraction of spikes (bottom central): number of reads mapped to ERCC spike-ins divided by the total sum of reads that were processed; Number of genes above 10 RPM (bottom right): number of genes with expression level above 10 reads per million. b, Number of good quality cells in each condition (rows) and batch (columns). c, Number of good quality cells per cluster (rows) and batch (columns). d, UMAP plot of the data with cells coloured by batch. In each batch there is a balanced distribution of cells in the two conditions and across the five clusters. e, The Pearson’s gamma (left panel) and the Average Silhouette Width (right panel) was calculated for each set of clusters obtained with 100 random subsamples of 60% of highly variable genes and different values of the deepSplit parameter (see Methods). The most robust clusters correspond to deepSplit values of 0 and 1. f, The changes in composition and number of clusters between the clustering obtained with deepSplit 0 (top) and 1 (bottom) are shown using the library ‘clustree’80. See methods for details on statistical analysis.

Extended Data Fig. 2 Cell cycle analysis and cluster connectivity.

a, Cell cycle analysis of epiblast cells from clusters 1, 3 and 4. Cell cycle phase was predicted with cyclone algorithm81 and shows that there are cells in S and G2M phase also in the loser and intermediate clusters. b, PAGA plot showing the connectivity of the five clusters of cells from CI-treated embryos. c-d, Diffusion map analysis in all epiblast cells (from DMSO and CI-treated embryos): cells are coloured according to the condition (c) and to the cluster (d). e, The pseudotime coordinate of the CI-treated epiblast cells obtained from the diffusion map including all epiblast cells correlates extremely well (with the pseudo-time coordinate obtained in the diffusion map calculated only from CI-treated epiblast cells (Fig. 2a). See methods for details on statistical analysis.

Extended Data Fig. 3 Analysis on epiblast cells from DMSO and CI-treated embryos.

a, Heatmap showing the expression pattern of all genes differentially expressed along the trajectory from winning to losing cells in Fig. 2d. b-c, Overlap of genes differentially expressed along the trajectory joining winning and losing epiblast cells in CI-treated embryos (Fig. 2a and panel d) and genes targeted by p53. Pie charts show the percentage of genes up- or down-regulated in loser cells within the group of target genes that are activated (b) or repressed (c) by p53. There is an enrichment of activated/repressed targets among genes upregulated/downregulated in losing cells respectively (p-value=1E-4). The list of p53 targets is taken from58. d, Scatter plots of the expression levels of different marker genes plotted against each other in loser epiblast cells (cluster 4). Loser cells have higher expression of pluripotency markers as well as higher expression of some lineage-specific markers and the co-expression of these markers is only weakly correlated - the Spearman’s correlation coefficient is shown. e-g Our scRNA-seq data from epiblast cells is projected on top of previously published data from epiblast collected from freshly isolated embryos at different stages (E5.5, E6.25 and E6.5; data from26). First, a diffusion map (e) and a pseudotime coordinate (f) is computed for the epiblast cells from freshly isolated embryos. Then, a pseudotime coordinate is estimated for our data after projecting it onto the diffusion map. Panel g shows the pseudotime coordinates for both datasets, split by stage, treatment and cluster. See methods for details on statistical analysis.

Extended Data Fig. 4 Cells eliminated during early mouse embryogenesis have activated stress responses.

a, Overlap of genes differentially expressed along the trajectory joining winning and losing epiblast cells in CI-treated embryos (Fig. 2a and Extended Data Fig. 3a) and genes related to the unfolded protein response and integrated protein response pathways (UPR_ISR, see Supplementary Table 3). From the 32 genes related to the UPR & ISR pathways, 12 are down-regulated in loser cells, 8 genes are up-regulated in loser cells, and 12 genes are not differentially expressed between loser and winner cells. There is a statistically significant enrichment of UPR&ISR genes among the up-regulated genes in loser cells (odds ratio=3.0, p-value=0.012). The intersection between UPR-ISR genes and the down regulated genes is not significant (odds ratio=1.2, p value=0.69). b-c, List of genes from UPR-ISR pathways that are statistically significantly up-regulated (b) or down-regulated (c) in loser cells. d, Scatterplots with the expression levels of genes involved in stress responses in epiblast cells from CI-treated embryos as a function of cells’ losing score. e, Experimental design with the approach taken to validate the expression of the stress response marker DDIT3 in epiblast cells from DMSO or CI-treated embryos. f, Representative micrographs of DMSO (upper panel) or CI-treated embryos (100 μM, lower panel) stained for DDIT3, quantified in (g). Nuclei are labelled with Hoechst. In control embryos (DMSO-treated), dying cells in the cavity show very high DDIT3 expression (arrow), while live cells in the epiblast of the CI-treated embryos show more modest levels of DDIT3 expression (arrowheads). Scale bar = 20 μm. g, Quantification of the percentage of epiblast cells with nuclear DDIT3 expression. N = 10 DMSO and N = 9 CI-treated embryos. Data shown as mean ± SEM. See methods for details on statistical analysis.

Source data

Extended Data Fig. 5 Mitochondrial function in wild-type, Bmpr1a−/− and 4n mESCs.

a-d, Metabolic flux analysis of wild-type and Bmpr1a/ mESCs. OCR profile and metabolic parameters assessed during the mitochondria stress test performed in pluripotency conditions (a). ECAR profile and metabolic parameters assessed during the glycolysis stress test performed in pluripotency conditions (b). Metabolic parameters from the mitochondria stress test found to be similar between wild-type and Bmpr1a/ mESCs during differentiation – day 3 (c). Metabolic parameters from the glycolysis stress test found to be similar between wild-type and Bmpr1a/ mESCs during differentiation – day 3 (d). Data obtained from 3 (a,b) or 5 (c,d) independent experiments, with 5 replicates per cell type in each assay. e-f, Analysis of mitochondrial membrane potential (Δψm) in defective mESCs maintained in pluripotency conditions, in separate or co-culture. Representative histograms of TMRM fluorescence and quantification for wild-type and Bmpr1a/ (e) and wild-type and 4n (f). g, Analysis of mitochondrial ROS in wild-type and Bmpr1a/ mESCs undergoing differentiation in separate or co-culture: representative histograms of mitoSOX Red fluorescence and quantification of the percentage of mitoSOX positive cells. Data shown as mean ± SEM from 3 (e-f) or 5 (g) independent experiments. See methods for details on statistical analysis.

Source data

Extended Data Fig. 6 Effect of actinonin in OPA1 expression in wild-type and Drp1−/− cells.

a, Western blot analysis of OPA1 expression in wild-type and Drp1/ cells treated with actinonin (Act, 150 μM) during 6 hours on the third day of differentiation, quantified in (b-c). b-c, Expression levels of L-OPA1 (b) and S-OPA1 (c) relative to ɑ-tubulin. Data shown as mean ± SEM of 3 independent experiments.

Source data

Extended Data Fig. 7 Analysis of SNPs in mtDNA in epiblast cells.

a-e, mtDNA heteroplasmy (plotted as Heteroplasmy = 1- frequency of most common allele) in epiblast cells from CI-treated embryos for five positions within the mt-Rnr2 gene. All these positions have an heteroplasmy that increases with the cells’ losing scores in a statistically significant way - the adjusted p-values are indicated at the top of each plot. f-k, The variation in the heteroplasmy across the CI-treated cells is not due to a batch effect for the 6 significant positions within the mt-Rnr1 gene. The number of cells analysed per cluster (and batch) is as follows: number of cells in Normal Epiblast :42 (1),16 (2),18 (3),0 (4),2 (5); number of cells in Intermediate: 42 (1), 28 (2), 28(3), 12 (4), 5 (5); number of cells in Loser Epiblast: 22 (1), 15(2), 20 (3), 2 (4), 7 (5). l, Correlation between the mtDNA heteroplasmy at all the statistically significant positions, six within the gene mt-Rnr1 and five within the gene mt-Rnr2. m, Schematic representation of the mitochondrial genome showing in red the positions that passed our filtering based on coverage and were considered for the heteroplasmy analysis. Only the genes that include these positions are indicated. See methods for details on statistical analysis.

Extended Data Fig. 8 Changes in mtDNA sequence are enough to trigger cell competition.

a, Illustration of the process of derivation of the mESCs lines from mice that are hybrid between the wild-caught strains (BG, HB or ST) and the lab mouse (C57BL/6N). These hybrid mice were generated elsewhere16 by ooplasmic transfer: the zygote of a C57BL/6N mouse was injected with ooplasm from a wild-caught mouse (orange, HB pictured). Therefore, these hybrid mice contain the nuclear background of the C57BL/6N strain and the mtDNA of wild-caught strain and potentially C57BL/6N mtDNA (heteroplasmic mice strains). mESCs lines were derived from the hybrid mice and characterised. b-f, Characterisation of the derived cell lines by flow cytometry, during pluripotency, in comparison to the wild-type cell line used in previous experiments (E14, 129/Ola background). Heteroplasmy analysis of the derived mESC lines from the hybrid mice, indicating the percentage of wild-derived mtDNA (b). Cell granularity (internal complexity) given as median fluorescence intensity of SSc-A laser (c). Cell size given as median fluorescence intensity of FSc-A laser (d). Analysis of the expression of mitochondrial markers: representative western blot and quantification of markers of mitochondrial mass (ATPB, mt-CO1 and TOMM20) and mitochondrial dynamics (DRP1, MFN1and MFN2), relative to vinculin, in cells derived from hybrid mice (e). f, Representative histograms and quantification of median TMRM fluorescence, indicative of Δψm, for the hybrid cell lines derived, in comparison to the wild-type cell line used in previous experiments (E14, 129/Ola background). g-i, Cell competition assays between hybrid cell lines maintained in pluripotency culture conditions. The ratio of final/initial cell numbers in separate or co-culture is shown. j, Experimental design for RNA-Seq and gene set enrichment analysis (GSEA). The isolation of RNA from winner HB(24%) and loser BG(95%) cells was performed after three days in separate or co-culture conditions, once cells have been subjected to FACS to isolate the two populations form mixed cultures. Data shown as mean ± SEM of 3 independent experiments. See methods for details on statistical analysis.

Source data

Extended Data Fig. 9 Metabolic flux analysis of the cells with different mtDNA variants: HB(100%), HB(24%), BG(95%) and C57BL/6N.

a, OCR profile during mitochondria stress test performed in pluripotency maintenance conditions. b-i, Metabolic parameters assessed during the during the mitochondria stress test performed in pluripotency conditions. Data obtained from 3 independent experiments, with 5 replicates per cell type in each assay. Error bars represent SEM. See methods for details on statistical analysis.

Source data

Extended Data Fig. 10 Common features of scRNA-seq and bulk RNA-seq datasets.

a, Terms significantly enriched among genes downregulated in BG(95%) (loser) ESCs in vitro when co-cultured with HB(24%) cells. The loss of mitochondrial activity emerges as a common feature between loser cells in vivo and in vitro. The gene enrichment analysis was performed using g-profiler tool (see Methods) and p-values were adjusted for multiple comparisons using the g:Profiler algorithm g:SCS (10.1093/nar/gkm226). b, Intersection between differentially expressed genes along the trajectory from winning to losing epiblast cells (‘in_vivo_scRNA-seq’; Fig. 2a and Extended Data Fig. 3a, and genes differentially expressed between co-cultured HB(24%) (winner) and BG(95%) (loser) ESCs (‘in_vitro_bulk_RNA-seq’). ‘Up’ and ‘Down’ here refer to genes up- or down-regulated in loser cells. For the intersection between down-regulated genes from scRNA-seq (in vivo) and down-regulated genes from bulk RNA-seq (in vitro): p-value, 1.71E-12; odds ratio 1.80. For the intersection between down-regulated genes from scRNA-seq (in vivo) and up-regulated genes from bulk RNA-seq (in vitro): p-value, 5.20E-3; odds ratio 0.67. For the intersection between up-regulated genes from scRNA-seq (in vivo) and down-regulated genes from bulk RNA-seq (in vitro): p-value, 4.87E-3; odds ratio 0.80. The intersection between up-regulated genes from sc-RNA-seq (in vivo) and up-regulated genes from bulk RNA-Seq (in vitro) is not statistically significant: p-value: 0.30, odds ratio 1.14. c, Intersection between the significantly enriched terms in genes upregulated or downregulated in loser cells in the epiblast of CI-treated embryos (‘in_vivo_scRNA-Seq’) or in our in vitro model of competition between co-cultured HB(24%) (winner) and BG(95%) (loser) ESCs (‘in_vitro_bulk_RNA-seq’). All the terms enriched among downregulated genes in vitro are also enriched in vivo. See methods for details on statistical analysis.

Supplementary information

Supplementary Information

Supplementary Figs. 1–8

Reporting Summary

Supplementary Tables 1–10

Supplementary Table 1. List of downregulated genes along the winner-to-loser trajectory in the embryo. Supplementary Table 2. List of upregulated genes along the winner-to-loser trajectory in the embryo. Supplementary Table 3. Genes related to the UPR and IPR pathways. Supplementary Table 4. List of background genes for the winner-to-loser trajectory in the embryo. Supplementary Table 5. List of downregulated genes in BG (95%) cells when co-cultured with HB (24%) cells. Supplementary Table 6. List of upregulated genes in BG (95%) cells when co-cultured with HB (24%) cells. Supplementary Table 7. List of background genes used for the analysis of genes differentially expressed between co-cultured BG (95%) and HB (24%) cells. Supplementary Table 8. Imaging equipment and settings. Supplementary Table 9. BG/HB wild-type mouse mtDNA and C57BL/6N-specific detection by ARMS–qPCR. Supplementary Table 10. ST wild-type mouse mtDNA and C57BL/6N-specific detection by ARMS–qPCR assay.

Source data

Source Data Fig. 2

Statistical source data.

Source Data Fig. 3

Statistical source data.

Source Data Fig. 4

Statistical source data.

Source Data Fig. 4

Statistical source data.

Source Data Fig. 4

Unprocessed western blots.

Source Data Fig. 5

Statistical source data.

Source Data Fig. 5

Unprocessed western blots.

Source Data Fig. 7

Statistical source data.

Source Data Extended Data Fig. 4

Statistical source data.

Source Data Extended Data Fig. 5

Statistical source data.

Source Data Extended Data Fig. 6

Statistical source data.

Source Data Extended Data Fig. 6

Unprocessed western blots.

Source Data Extended Data Fig. 8

Statistical source data.

Source Data Extended Data Fig. 8

Unprocessed western blots.

Source Data Extended Data Fig. 9

Statistical source data.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Lima, A., Lubatti, G., Burgstaller, J. et al. Cell competition acts as a purifying selection to eliminate cells with mitochondrial defects during early mouse development. Nat Metab 3, 1091–1108 (2021). https://doi.org/10.1038/s42255-021-00422-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s42255-021-00422-7

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing