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Bob described cell division of Leishmania promastigotes in vivid detail
and accuracy. In the case of L donovani and L amazonensis amastigotes,
I noted the formation of divison furrows from both anterior and posterior
ends. However, the former seems to be formed faster than the latter. I
don't know if this is true all the time for all species. Nor can I attach
any particular significance to it.
<p>KP
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<p>killickendrick wrote:
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Patrick Bastien asks for information
on the sequence of the division of organelles of leishmanial promastogotes.
Observations on Giemsa-stained smears of <i>L. infantum</i> in the midgut
of one of its natural vectors, <i>P.ariasi</i>, show that there appears
to be a constant sequence of events. See page 407 in Killick-Kendrick (1979)
In <i>Biology of Kinetoplastida</i> vol 2 and the account and figures on
pp 126-7 in Molyneux & Killick-Kendrick (1987) in <i>The Leishmaniases
in Biology and Medicine</i>, vol 1.The sequence is:promastogote increases
in size and a second basal body appears;a daughter flagellum (which stays
smaller than the original throughout the process) arises from this second
basal body;kinetoplast enlarges and stains diffusely - but does not divide
yet;nucleus enlarges and divides into two equal parts which usually lie
side by side, but are sometimes in tandem;the kinetoplast, which by now
lies across the body, assumes a dumbbell shape and then divides into two
equal parts;the daughter kinetoplasts, lying just anterior to the nuclei,
are small and stain densely with Giemsa's stain;the body of the promastigote
divides into two equal parts by a cleft that arises between the two flagella
and progressively continues posteriorly leaving one nucleus and one kinetoplast
in each daughter individual.The two new promastigotes are about half the
size of the original promastigote and morphologically identical except
that the flagellum of one is shorter than that of the other.In cultures,
the kinetoplast sometimes divides before the nucleus, but I have never
seen this sequence in stained smears of any <i>Leishmania </i>species.</blockquote>
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