Lecture 4: Trypanosomes Flashcards
Heteroxenous
Involving a vertebrate and an invertebrate host
Hemoflagellates
Living in the blood or fixed tissues of animals
Kinetoplast
A disk shaped mitochondrion compartment packed with kDNA
Maxicircles
Edited mRNAs that translate into mitochondrial
proteins (kDNA)
Minicircles
Encode guide RNA for RNA editing (kDNA)
Kinetosome (basal body)
Centriole where an axoneme arises
Glycocalyx
Surface coat made of glycoproteins
What is the disease transmission method of African Trypanosomiasis (African Sleeping Sickness?)
Salivaria
Salivaria
Trypanosomes that develop in the anterior parts of digestive tract of the vector are transmitted from the vector to the vertebrate host by injection
during blood feeding
What is the disease transmission method of American Trypanosomiasis?
Stercoraria
Stercoraria
Parasites develop in the hindgut of the vector and transmission of the parasites from the vector to the vertebrate host is through fecal contamination
Monoxenous
Development only in a single species (usually an arthropod).
Flagellar pocket
A depression on the parasite surface, where a flagellum arises
What is within the structure of a Trypanosome?
- Kinestome
- Flagellar Pocket
- Undulating Membrane
- Glycocalyx
What are the life stages of a Trypanosome?
- Amastigote
- Choanomastigote
- Promastigote
- Opisthomastigote
- Epimastigote
- Trypomastigote
How are the life stages of trypanosomes classified?
Depending on the shape, position of the kinetosome and kinetoplast, development of the flagellum, or shape of the flagellar pocket.
What is the biological vector of African Trypanosomiasis?
The Tsetse Fly: Glossina spp.
Trypomastigote Life Stage
kinetoplast and kinetosome at the posterior end, flagellum runs along the surface (typical of Trypanosoma in the blood stream and metacyclic form in the vector’s salivary gland).
Epimastigote Life Stage
Kinetoplast and kinetosome are between the nucleus and anterior end, a short undulating membrane lies near the base of the flagellum (Trypanosoma development in tsetse midgut).
Promastigote Life Stage
Body elongated, flagellum extending forward, kinetoplast and kinetosome in front of the nucleus, near anterior of the body (e.g., Leishmania in the sand fly).
Amastigote Life Stage
Body round, flagellum very short (E.g., Leishmania development in vertebrate host).
