biostudies-literatureYesharim YEuropean Research CouncilEuropean Molecular Biology LaboratoryIsrael Science FoundationIsrael Science Foundation (ISF)EIPOD-LinC749-788https://www.ebi.ac.uk/biostudies/studies/S-EPMC12864844biostudies-literatureUnknown45(3)Cell fate decisions require tight regulation of gene expression. In planarians, highly regenerative flatworms, the mRNA modification N⁶-methyladenosine (m⁶A) modulates progenitor production and fate. However, the mechanisms governing m⁶A deposition in the planarian transcriptome, and the role of their expanded family of YTHDF m⁶A reader proteins in orchestrating biological functions, remain unclear. Here, we generated the first single-nucleotide resolution map of m⁶A in planarians, and revealed that simple sequence rules guide m⁶A deposition, facilitating the flexible evolutionary gain and loss of these marks. Functional analyses of the five YTHDF planarian m⁶A readers revealed that while individual reader expression is dispensable, together, the planarian YTHDF proteins regulate the produThe EMBO journalSingle-nucleotide m⁶A mapping uncovers redundant YTHDF function in planarian progenitor fate selection.PMC128648445431652039/18913/21853640Schwartz SBarboy-Smoliarenko JShachar RYesharim YWurtzel OCherian PVVu HTShwarzbard OPalavalli AfalseSingle-nucleotide m⁶A mapping uncovers redundant YTHDF function in planarian progenitor fate selection.Cell fate decisions require tight regulation of gene expression. In planarians, highly regenerative flatworms, the mRNA modification N⁶-methyladenosine (m⁶A) modulates progenitor production and fate. However, the mechanisms governing m⁶A deposition in the planarian transcriptome, and the role of their expanded family of YTHDF m⁶A reader proteins in orchestrating biological functions, remain unclear. Here, we generated the first single-nucleotide resolution map of m⁶A in planarians, and revealed that simple sequence rules guide m⁶A deposition, facilitating the flexible evolutionary gain and loss of these marks. Functional analyses of the five YTHDF planarian m⁶A readers revealed that while individual reader expression is dispensable, together, the planarian YTHDF proteins regulate the produ2026-01-01T00:00:00Z2026 Feb2026-07-15T12:03:00.935Z2026-07-04T03:12:36.96ZS-EPMC128648444148436310.1038/s44318-025-00662-3