Geographic distribution of the major FeLV genotypic groups (I, II, III) and the seven clades of Genotype I.

Each color-coded dot represents one infected cat (small dot) or 5 infected cats (large dot). Colored areas indicate provinces of Japan such as Hokkaidō, Tōhoku, Kantō, Chūbu, Kinki, Chūgoku, Shikoku and Kyūshū. A two-letter code was assigned to each prefecture as described in Table S2. A detailed summary of the geographic distribution of all groups is provided in Table S3.