Project Details


Cell differentiation at the molecular level is still not well understood.
The long-term objective of this proposal is to elucidate the molecular
mechanisms involved during differentiation of the parasitic protozoan
Leishmania mexicana amazonensis. Regulation of tubulin gene expression has
been chosen for an initial study, because leishmanias have a motile,
flagellated promastigote stage and a nonmotile, intracellular amastigote
stage in their life cycle, and the two stages, as well as transformation
between stages, can be maintained under laboratory conditions. Leishmanias possess a variety of functionally distinct microtubules,
including flagellar, subpellicular and nuclear spindle types. With the
hybridoma technique, monoclonal antibodies will be generated; and
antibodies against specific components of the leishmanial cytoskeleton, or
against specific types of microtubules, will be selected, and antigenic
changes during amastigote-to-promastigote transformation in vitro will be
identified. The aim is to dissect the cytoskeletal elements with
monoclonal antibodies because the leishmanial microtubular system can be
viewed as a potential target structure for chemotherapeutic attack. Expression of tubulin genes during leishmanial differentiation will also be
analyzed at the nucleic acid level. Tubulin specific cDNA clones will be
selected from leishmanial cDNA libraries using probes containing
Chlamydomonas or chicken tubulin sequences. Restriction maps of cloned
tubulin inserts will be used to characterize the different stage-specific
tubulin RNAs being expressed by the amastigotes and the promastigotes. S1
nucleases protection experiments will be performed in order to compare the
tubuline mRNAs between the two developmental stages. Restriction fragments
of tubulin coding and flanking sequences will be used to investigate both
the tubuline gene organization in the leishmanial genome, and the
expression of tubulin RNAs during leishmanial differentiation. The aim is
to study the leishmanial tubulin system as a model for the regulation of
gene expression during cell differentiation.
Effective start/end date9/1/858/31/88


  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health


  • Medicine(all)
  • Immunology and Microbiology(all)

Fingerprint Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.