kinetoplast

thumb|Electron micrograph of normal kinetoplast (K) of Trypanosoma brucei A kinetoplast is a network of circular DNA (called kDNA) inside a mitochondrion that contains many copies of the mitochondrial genome. The most common kinetoplast structure is a disk, but they have been observed in other arrangements. Kinetoplasts are only found in Excavata of the class Kinetoplastida. The variation in the structures of kinetoplasts may reflect phylogenic relationships between kinetoplastids. A kinetoplast is usually adjacent to the organism's flagellar basal body, suggesting that it is bound to some components of the cytoskeleton. In Trypanosoma brucei this cytoskeletal connection is called the tripartite attachment complex and includes the protein p166.

==Trypanosoma== In trypanosomes, a group of flagellated protozoans, the kinetoplast exists as a dense granule of DNA within the mitochondrion. Trypanosoma brucei, the parasite which causes African trypanosomiasis (African sleeping sickness), is an example of a trypanosome with a kinetoplast. Its kinetoplast is easily visible in samples stained with DAPI, a fluorescent DNA stain, or by the use of fluorescent in situ hybridization (FISH) with BrdU, a thymidine analogue. Another parasite in the genus, Trypanosoma cruzi, causes Chagas disease in humans (primarily in Central and South America), which is transmitted through the kissing bug. Although African sleeping sickness is more dangerous than Chagas disease, the kinetoplast of T. cruzi is significantly larger than that of T. brucei. Trypanosoma equiperdum causes the disease dourine in horses, and is the only sexually transmitted trypanosome infection. The kinetoplasts of T. equiperdum are unique in that every minicircle has the same genetic sequence.