Kinetoplastids are
eukaryotic and possess normal eukaryotic organelles, for example the
nucleus, mitochondrion,
golgi apparatus and flagellum. Along with these universal structures, kinetoplastids have several distinguishing morphological features such as the kinetoplast, sub-pellicular microtubule array and paraflagellar rod.
Mitochondrion and kinetoplast DNA The kinetoplast, after which the class is named, is a dense DNA-containing granule within the cell's single mitochondrion, containing many copies of the mitochondrial
genome. The structure is made up of a network of concatenated circular DNA molecules and their related structural proteins along with
DNA and
RNA polymerases. The kinetoplast is found at the base of a cell's flagella and is associated to the flagellum
basal body by a
cytoskeletal structure.
Cytoskeleton The cytoskeleton of kinetoplastids is primarily made up of
microtubules. These make a highly regular array, the sub-pellicular array, which runs parallel just under the cell surface along the long axis of the cell. Other microtubules with more specialised roles, such as the
rootlet microtubules, are also present. Kinetoplastids are capable of forming
actin microfilaments but their role in the cytoskeleton is not clear. Other cytoskeletal structures include the specialised attachment between the flagellum and the kinetoplast.
Flagella All kinetoplastids possess at least one flagellum; species in the order trypanosomatida have one and
bodonida have two. In kinetoplastids with two flagella most forms have a leading and trailing flagellum, the latter of which may be attached to the side of the cell. The flagella are used for locomotion and attachment to surfaces. The bases of the flagella are found in a specialised pocket structure which is also the location of the
cytostome. ==Life cycle==