The basic morphology of Trypanosoma gambiense is that of a single-celled organism, known as a protozoan. It has a characteristic elongated, cigar-shaped body, with a distinct anterior and posterior end. The body is surrounded by a plasma membrane, which encloses the cytoplasm and organelles. In this article, we will learn the morphology of Trypanosoma gambiense.
Morphology of Trypanosoma gambiense
1. Shape and Size
-
-
- Trypanosoma gambiense is unicellular, microscopic, elongated, leaf-like, flattened, and tapering at both sides.
- Its length is about 10-40µ and its width is about 2.5-10µ.
- The anterior end is pointed and the posterior end is blunt.
- It is a polymorphic species and occurs in two developmental forms, the trypanosome form, and the crithidial form.
- In the bloodstream of man, the trypanosome form may be long slender or short stumpy, or intermediate between the two.
- In the tsetse fly, the trypanosome form is long and slender in the midgut, and short and stumpy in the salivary gland.
- The crithidial form is represented only in the salivary glands of the tsetse fly.
-
2. Pellicle
-
-
- The whole body is surrounded externally by pellicle.
- The pellicle is a thin and elastic covering.
- It is supported by the fine fibrils, called microtubules.
- Microtubules may help to maintain the shape of the organism while it swims in the blood plasma.
-
3. Flagellum
-
-
- Trypanosoma gambiense is uniflagellate as it has a single flagellum.
- The flagellum arises from the posterior part of the body.
- It runs forward, attached along the entire length of the body, and becomes free at the anterior end of the body.
- When the trypanosome moves in blood, the undulating waves pass from the tip to the base of the flagellum.
-
4. Undulating Membrane
-
-
- When the flagellum beats, the pellicle, to which it is attached, is pulled up into a membranous fold called the undulating membrane.
- It may be an adaptation for locomotion in fluid like blood.
-
5. Cytoplasm
-
-
- The cytoplasm is enclosed within the pellicle.
- The cytoplasm is not differentiated into ectoplasm and endoplasm.
- An elongated mitochondrion with tubular cristae is present in the cytoplasm.
- Just near the basal body of the flagellum (at the posterior end of the body), the mitochondrion forms a disk-like structure called the parabasal body or kinetoplast.
- The kinetoplast includes a double-stranded DNA helix.
- A Golgi apparatus, endoplasmic reticulum, and ribosome are present in the cytoplasm.
- The cytoplasm also contains numerous greenish granules called voluntin granules. These are supposed to be stored food particles.
- Various small vacuoles are also seen in the cytoplasm, some with hydrolytic enzymes.
-
6. Nucleus
-
-
- The nucleus is present within the cytoplasm.
- The nucleus is large, oval, and vesicular.
- The nuclear membrane is a double-unit membrane and bears pores.
- The nucleolus is present at the center of the nucleus and surrounded by a clear space.
- Numerous chromosomes are present within the nucleoplasm.
-
———— THE END ———–
Read More:
- African Sleeping Sickness or Trypanosomiasis: Symptoms, Diagnosis, Treatment, and Prevention
- Life Cycle of Trypanosoma gambiense | Diagram
- General Characters of All Phylum of The Invertebrates.
Reference:
- “Modern Textbook of Zoology Invertebrates” written by R. L. Kotpal.
- CDC – African Trypanosomiasis – Biology