Related Experiment Videos
Disposition of the manchette and related events in the feline spermatid
Abstract:
The manchette is a transient microtubular organelle previously considered to "disappear" prior to formation of the definitive midpiece of the spermatozoon. Goodrowe and Heath (1984) have suggested, however, that in stallions the final disposition of the microtubules of the manchette is into the residual cytoplasm. In the present study, spermiogenesis was examined by transmission electron microscopy of testicular samples from eight cats. Feline spermatids also had a manchette of cylindrical shape, largely located in a cytoplasmic collar peripheral to the presumptive midpiece. The parallel microtubules of the manchette were interconnected by arms. Some of these arms were still present after rupture of the manchette cylinder and movement of the microtubules into the residual cytoplasm. On displacement of the manchette microtubules, mitochondria, spherical in shape and peripherally located, moved centrally to elongate and encircle the flagellum to form the definitive midpiece.
Insights
The feline manchette, a microtubular structure, does not disappear but relocates to residual cytoplasm. This movement facilitates mitochondrial arrangement for the definitive sperm midpiece formation.
Area of Science:
- Reproductive biology
- Cell biology
- Spermatogenesis
Background:
- The manchette is a transient microtubular organelle.
- It was previously thought to disappear before definitive midpiece formation.
- Previous research suggested its microtubules might enter residual cytoplasm in stallions.
Purpose of the Study:
- To investigate the fate of the manchette during feline spermiogenesis.
- To clarify the manchette's role in definitive midpiece formation in cats.
Main Methods:
- Transmission electron microscopy (TEM) of feline testicular samples.
- Examination of spermiogenesis in eight domestic cats.
Main Results:
- Feline spermatids possess a cylindrical manchette in a peripheral cytoplasmic collar.
- Manchette microtubules are interconnected by arms.
- Microtubules move into residual cytoplasm after manchette rupture.
- Mitochondria migrate centrally to elongate and encircle the flagellum, forming the definitive midpiece.
Conclusions:
- The manchette does not disappear but relocates to the residual cytoplasm in feline spermiogenesis.
- The manchette's displacement is crucial for the central positioning and elongation of mitochondria.
- This process leads to the formation of the definitive sperm midpiece in cats.