A candidate mitochondrial genetic-code reassignment in Pneumocystis jirovecii: a public-data research summary

Comparisons of public mitochondrial records raise a genetic-code hypothesis in Pneumocystis jirovecii: UGA may specify arginine at sites currently annotated as tryptophan. The signal recurs across the examined records, but accession counts overstate the number of independent biological samples because the set includes a reference record and its source sequence. A public RNA dataset bears on an alternative explanation without establishing protein translation. No direct protein-level evidence or demonstrated decoding mechanism is available in the analysis. This note documents a candidate reassignment, not a confirmed genetic code or a clinical finding.