Evidence of sexual reproduction in the protozoan parasite Leishmania of the old world

ABSTRACT

Three Leishmania strains of the old world were included in this study. Both the amastigote and promastigote stages were subjected to staining by Feulgen procedure and examined by computerized image analyzer system to determine their nuclear DNA content. Results of this study showed that in the promastigote stage, there is a single cell population; whereas in the amastigote stage, there are two populations of parasite nuclei, one with low level of DNA resembling that of the promastigote and a second population with double DNA level. The latter is formed when apparently two nuclei fused and form one with double DNA level. The data obtained in the present study indicated that Leishmania of the old world can undergo nuclear fusion, which is a strong evidence for the presence of sexual reproduction in the parasite