Fig. 5: Introduction of Braf^V600E stimulates mitotic activation of Rax⁺ tanycytes.

a Experimental scheme describing the induction of somatic genetic mutation in tanycytes using Rax-CreER^T2::Braf^V600E mice and detection of cell division in ME. b Sample confocal images showing the mitotic cells in the ME of control and Braf-mutant mice. Scale bar: 50 µm. c Quantification of EdU⁺ cell number in EZ and SEZ of control and mutant mice. Boxes represent IQR, whiskers extend to ±1.5 IQR, and significance was analyzed by unpaired two-tailed Student’s t test (n = 12 and 14 sections from three mice for control and mutant groups). ***P < 0.001. d Representative confocal images stained for EdU with Sox2, Olig2, CC1, and S100β in Rax-CreER^T2::Braf^V600E mice receiving tamoxifen injection. Scale bar: 20 µm. e Quantification of the number of mitotic cells expressing different cell markers (n = 20 sections from four mice). Boxes represent IQR, whiskers extend to ±1.5 IQR and significance was analyzed by unpaired two-tailed Student’s t test (n = 20, 21, 20, 21, 20, 21, 20, 21, 10, 17, 18, 10, 10, 10, 18, and 10 sections from at least three mice from bottom to top boxes). *P < 0.05; ***P < 0.001; N.S. not significant. f Sample images showing mutant Braf^V600E activates mitotic division of Sox2⁺Olig2⁻ tanycytes in ME. White arrowheads signify Sox2⁺Olig2⁺ OPCs while yellow arrowheads indicate tanycytes. Scale bar: 10 µm. Source data are provided as a Source Data file. The precise P values are summarized in Supplementary Data 3.