Distribution of validated variants in testis slices 1D (A), 2F (B), 4B (C), and 5J (D). Testicular biopsy numbers are located to the left of each testis slice. Some biopsies were further dissected into two pieces of which the orientation is unknown; these are indicated with a diagonal dashed line (e.g., Tes2F 30a,b). Each variant has a distinct number (as listed in Table 1) and is colored according to gene—FGFR2 (purple), FGFR3 (orange), KRAS (black), PTPN11 (blue), RET (pink), and newly associated gene (red)—and is also indicated on the figure key. The size of each circle is proportional to the observed variant allele frequency (VAF) in each biopsy as indicated by black dots on the figure key. Identical variants in different biopsies have been connected by lines that likely track the seminiferous tubule trajectory across the testis and therefore may represent a single “clonal event”; note that the path of the clone has been arbitrarily drawn and may not represent the true trajectory of the tubule. Dark gray segments represent biopsies that were not sequenced due to insufficient material quality/quantity (see Methods). Light gray segments represent nontubular regions of tissue. The age of the individual from whom the testis was collected is indicated on the figure (for further details on the testicular samples, see Supplemental Table S5). The remaining five slices of Tes4 are presented in Supplemental Figure S2. Tes3D is omitted as no variants were identified. Variants are numbered in order of tier: Tier 1 (1–39), Tier 2 (40–57), Tier 3 (58–61). Letters in brackets refer to variants associated with germline disorders [G] and/or reported in the COSMIC database [C]; for further details, see also Table 1 and Supplemental Table S3.
