promastigote

Term now generally used instead of “leptomonad” or “leptomonad stage,” to avoid confusion with the flagellate genus Leptomonas. It denotes the flagellate stage of a trypanosomatid protozoan in which the flagellum arises from a kinetoplast in front of the nucleus and emerges from the anterior end of the organism; usually an extracellular phase, as in the insect intermediate host (or in culture) of Leishmania parasites. [pro- + G. mastix, whip]

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pro·mas·ti·gote -'mas-ti-.gōt n a protozoan that belongs to the family Trypanosomatidae and esp. to the genus Leishmania and that is in a flagellated usu. extracellular stage characterized by a single anterior flagellum and no undulating membrane

promastigote adj

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pro·mas·ti·gote (pro-masґtĭ-gōt) [pro- + Gr. mastix whip] a morphological stage in the life cycle of certain trypanosomatid protozoa; the elongate or pear-shaped cell has a central nucleus, anteriorly located kinetoplast and basal body, free-flowing flagellum emerging from the anterior end, and no undulating membrane. Cf. amastigote, choanomastigote, epimastigote, opisthomastigote, and trypomastigote.