Are Kinetoplastids excavates?
Are Kinetoplastids excavates?
A kinetoplast is a network of circular DNA (called kDNA) inside a large 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.
What are Kinetoplasts?
Definition of kinetoplast : a DNA-containing organelle especially of trypanosomes usually found in an elongated mitochondrian located adjacent to the basal body.
How do Kinetoplastids move?
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.
Where can Kinetoplastids be found?
The kinetoplast is a dark Giemsa-staining structure which is distinct from the nucleus (Figure). The size of the kinetoplast will vary according to species. The kinetoplast is found near the basal body which is located at the base of the flagellum (Figure).
Is Trypanosoma a Excavata?
4.3 Excavata The Euglenozoa, include the Trypanosomatids, that are responsible for three major human diseases, sleeping sickness (African trypanosomiasis), Chagas disease (South American trypanosomiasis) and leishmaniasis.
What is kDNA?
Kinetoplast DNA (kDNA) is the most structurally complex mitochondrial DNA in nature. Unique to the single mitochondrion of unicellular flagellates of the order Kinetoplastida, kDNA is best known as a giant network of thousands of catenated circular DNAs (an electron micrograph of a network is shown in Fig.
What are the defining features of the kinetoplastids?
Cellular features of the kinetoplastids include: A single flagellum present in many of the morphological forms. A paraxial rods runs along beside the axoneme. The flagellum is sometimes attached to cell body to form undulating membrane.
Are kinetoplastids asexual?
While it is clear that these organisms are able to reproduce asexually, the existence of a sexual cycle was, until recently, an entirely open question. The results which these techniques have produced make it clear that the kinetoplastid protozoans cannot be regarded as a totally asexual group of organisms.
What does a kinetoplast do?
In kinetoplasts, maxicircles play an important role in encoding ribosomal RNAs as well as various proteins involved in bioenergetic processes within the mitochondria. Here, some of the transcripts of RNA may later be modified through the insertion or deletion of uridine residues.
Is Kinetoplastids unicellular?
Kinetoplastids are flagellated protozoans, which are unicellular eukaryotic organisms. They include free-living microorganisms, as well as parasites of diverse invertebrate, vertebrate, and plant species.
Which is the best description of a Kinetoplastida?
Kinetoplastida. One family of kinetoplastids, the trypanosomatids, is notable as it includes several genera which are exclusively parasitic. Bodo is a typical genus within kinetoplastida and including various common free-living species which feed on bacteria. Others include Cryptobia and the parasitic Leishmania .
What kind of organism is Kinetoplastida Honigberg 1963?
Kinetoplastida Honigberg 1963 emend. Kinetoplastida (or Kinetoplastea, as a class) is a group of flagellated protists belonging to the phylum Euglenozoa, and characterised by the presence of an organelle with a large massed DNA called kinetoplast (hence the name).
Can a kinetoplastid be translated into a mitochondrial mRNA?
Translation of mitochondrial mRNAs of kinetoplastids is impossible without massive RNA editing of the transcripts by insertion and deletion of uridine (reviewed in Aphasizhev and Aphasizheva, 2011).
When did Lynn Margulis accept Kinetoplastida as an order?
Lynn Margulis, who initially accepted Kinetoplastida as an order in 1974, later placed it as a class. Use of Kinetoplastida as an order also creates confusion as there is already an older name Trypanosomatida Kent, 1880, under which the kinetoplastids are most often placed.
