Fig 2. Simplified life cycle of L. tarentolae (Sauroleishmania).

Sand fly (Sergentomyia) takes a blood meal from a gecko and thereby ingests promastigotes (major form) and some amastigotes/amastigote-like cells (minor form) of L. tarentolae. Inside the gut of the sand fly, immune cells burst, and the phagocytized part of Leishmania is released. Promastigotes colonize the lumen of the cloaca, the intestine (hindgut), and rarely, the blood of the sand fly. Although not known, it is possible that promastigotes (and amastigotes) of L. tarentolae undergo several transformations inside the sand fly, with stages of procyclic, nectomonad, leptomonad, haptomonad, and subsequently, metacyclic promastigotes (stages adapted from [80]). Metacyclic promastigotes would be the gecko-infective stage, and they are transferred back to a gecko during a new blood meal. Inside the gecko, promastigotes mainly live free in the blood. A small part is probably phagocytized by immune cells (monocytes and macrophages). Phagocytosed promastigotes might change back into amastigotes/amastigote-like cells, and the life cycle repeats. Immune cells are represented in blue, and erythrocytes are represented in red.