On the Encystment of Leptomonas sp. (Kinetoplastida: Trypanosomatidae), a Parasite of the Silkworm, Bombyx mori Linnaeus

Abstract

SYNOPSIS. Promastigotes of Leptomonas sp., a flagellate parasite of the silkworm, Bombyx mori, multiplied by binary fission with the following sequence of events: duplication of the flagellum; division of the kinetoplast and the nucleus; spatial separation of the kinetoplast: and cytokinesis resulting in the formation of 2 daughter promastigotes. In the early stages of encystment, promastigotes aggregated in a rosette and assumed a stumpy form. The nucleus and kinetoplast of the stumpy promastigotes were double, suggesting a possibility of fusion of the organism in the rosette. When most of the promastigotes in the cluster became stumpy, each individual was isolated from the cluster and acquired a thick coat with an acidophilic substance, thus forming a cyst.