Prevalence of de novo variants. Prevalence (A) per gene type (protein coding genes, tRNA, rRNA genes, and D-loop) and (B) per protein-coding gene. The observed number of variants in all oocytes is expressed as the number of variants per nt. If a de novo mutation occurred multiple times, it is only counted once in the construction of these distributions. rRNA, ribosomal RNA; tRNA, transfer RNA.