Finding. Human iPS cells pick up BCOR mutations in the dish, mostly truncating indels in exon 7, a pattern that does not match BCOR in tumors. Badja, Nik-Zainal and colleagues show the functional cost: chromatin, transcriptome, and proteome swing toward developmental genes, pluripotency genes, and mitochondrial-metabolism genes. A cheap TaqMan test catches the mutants across lines. Fix the allele with CRISPR and the molecular state only partly comes home. The adaptation remembers.
Why this paper is on Mito.news
Because a lot of mitochondrial disease modeling starts in iPS cells. If the culture already turned mitochondrial metabolism programs on, your patient-versus-control OCR, mtDNA, or differentiation assay is standing on a mutant co-repressor. The partial CRISPR revert means “we sequenced BCOR and it is wild type now” is not enough.
How to read the score
Low seventies. Real practical hit, mitochondrial program as one of three activated axes, not a new respiratory-chain mechanism. Confidence is medium on the organelle physiology, high on the culture-genetics warning.
Caveats
No Seahorse number in the abstract. TaqMan will miss rare exons. Do not discard every old iPSC line without running the assay.
What to do with it
Add BCOR exon-7 surveillance to iPSC QA. If a mitochondrial phenotype appeared after high passage, genotype BCOR before you write the paper. Prefer early stocks; do not trust late correction as a full rescue.