2. metamorphosis of spermatid, spermiogenesis, spermateleosis?
This involves changes in nuclear as well
as cytoplasmic level.
The transformation of a haploid, non-
functional, non-motile, round-shaped
immature spermatid into a functional,
motile champion swimmer ,mature
spermatozoa the process is called
spermateleosis.
3. Modifications
CHANGES IN NUCLEUS
The nucleus shrinks by losing the water
from the nucleoplasm, chromosomes
are six times more closely packed.
from a spherical shape to an elongated
& narrow form.
spherical shape narrow
shape
Nucleus
RNA & other acidic proteins are
eliminated. The nucleus changes
4. on the anterior end of the nucleus.
According to Burgos & Fawcett, the
acrosome is derived from a part of golgi
apparatus of the spermatid.
ACROSOME FORMATION
Soon, the cap bound a single-unit plasma membrane and form an
acrosome.
Firstly, one of the vacuoles of golgi body
develops an acrosomal granule. Gradually
acrosomal granule accumulates lytic
enzymes & forms a cap-like structure
5. Neck
Centriole
During the early stage of Spermiogenesis,
two centrioles shift just behind the
nucleus.
FORMATION OF NECK
One of them comes close to the nucleus & lie
in the posterior end of the nucleus called
proximal centriole.
The second one lies just next to it along with
the longitudinal axis of the sperm.
The second one known as distal centriole, is appointed for the development
of axial filament.
6. The mitochondria spirally coiled forming
a sheath around the axial filament and distal centriole.
The mitochondria from different regions of
the spermatid accumulate in the middle
piece around the proximal part of the
axial filament and distal centriole.
FORMATION OF MIDDLE PIECE
7. Serves to shape the developing head and as a conduit to transport
protein to the growing tail as well as tail development.
During the loss of the cytoplasm, some
parts of the cytoplasm form a condensed
layer around the periphery of the
acrosome called manchette.
FORMATION OF MANCHETTE
s skirt type structure.
The manchette is composed of up to 1000
microtubules, bundled together, in a gras
8. Distal centriole gives rise to a
contractile and microtubular structure
called axoneme.
FORMATION OF TAIL
The axoneme contains microtubules that
are arranged in a 9 + 2 configuration
Which gets surrounded by cytoplasmic
sheath. Both collectively form the tail.
9. Non-motile mature spermatozoa gain
motility as they progress through
development within the epididymis.
MATURATION PHASE
The process by which spermatozoa
travel to the epididymis and develop
into motile spermatozoa are termed
spermiation.
