Map of Japan and Southeast Asia showing the geographic origins of P. leiognathi strains bearing single or multiple lux-rib operons. The scale bar is approximately 500 km. The inset shows an enlarged map of the main islands of Japan (some landmasses were omitted for clarity). Locations: a, Sagami Bay, Kanagawa Prefecture, Honshu, Japan; b, Suruga Bay, Shizuoka Prefecture, Honshu, Japan; c, Wakasa Bay, Fukui Prefecture, Honshu, Japan; d, Ago Bay, Mie Prefecture, Honshu, Japan; e, Tosa Bay, Kochi Prefecture, Shikoku, Japan; f, Nakagusuku Bay, Okinawa-honto, Okinawa Prefecture, Japan; g, Funauki Bay, Iriomote Island, Okinawa Prefecture, Japan; h, Taipei, Taiwan; i, Dahsi, Taiwan; j, Manila Bay, Luzon, Philippine Islands; k, Iloilo, Panay, Philippine Islands; l, Palawan, Philippine Islands; m, Gulf of Thailand. Numbers next to each location indicate the number of strains identified as bearing single (white area in circle) or multiple (gray area in circle) lux-rib operons.