Spermiogenesis

What is spermiogenesis?

Spermiogenesis is the process by which spermatids become spermatozoa by reducing the cytoplasm. During the process the nucleus elongates and is located in the head of the spermatozoon, the mitochondria are located in the neck and the centrioles form a kind of tail. Before leaving the penis for fertilization, the spermatozoa pass through the epididymis of the testicle, where spermiohistogenesis takes place. In this process, the acrosome (vesicle with enzymes) and a glycolemma or layer that protects it from the PH of the vagina are obtained, which disappears before reaching the egg.

Thus, spermiogenesis are the modifications that the primitive germ cells undergo until they become mature spermatozoa. During their development these cells pass from the stage of primary to secondary spermatocytes and finally to spermatids with half the number of chromosomes. This is followed by sperm maturation or spermiogenesis, a process that lasts about 60 days.

All the changes that the spermatids undergo until they become mature spermatozoa are included in four phases:

1. Goigi phase. This is the period from the formation of the round spermatid to the creation of a spherical acrosomal granule associated with the nuclear membrane. During this part the position of the Goigi is reversed, which is the trans face focused to the nucleus. In addition, chromatin condenses, mitochondria move to the periphery, attached to the plasma membrane and an achromosomal vesicle is formed. On the opposite side of this there is a deformation of the nuclear membrane forming the implantation pit, where the centrioles will migrate.
2. Cap stage. Comprises spermatids with a growing cephalic acrosomal cap. The acrosomal vesicle should form a larger angle, 45 degrees, with the center of the nucleus. Here the flagellum begins to form. At its beginning, the annulus is formed, a ring-like structure from which columns run along the main area of the flagellum. A ring surrounding the nucleus (manchette) will also form, which acts as a microtubule organizer and from which, in turn, microtubules will exit to the rear of the cell. It will help all organelles to move to that area, except for the Goigi, as it will do so without the need for microtubules. The acrosomal vesicle is attached to the nucleus by the acroplaxma.
3. Acrosomal phase. It is characterized by a deformation of the nucleus and a change in the orientation of the cell. The flagellum will now be facing the lumen of the seminiferous tubule. The chromatin condenses into sheets and at the junction of the flagellum with the nucleus the capitellum will form. The acrosome is already formed. At this stage the manchette disappears and the mitochondrial cells begin to cluster in the annulus and nucleus.
4. Maturation phase. The nucleus condenses until a paracrystalline structure is obtained. Mitochondria cluster around the microtubules, between the annulus and the nucleus. Almost all of the cytoplasm and organelles are lost, except for the mitochondria that form the helix and two centrioles, necessary for the flagellum.

Spermiogenesis is the process of sperm maturation.

The changes that spermatozoa undergo in spermiogenesis are:

• Acrosome formation. The acrosome is located at the apical end with two membranes, internal and external. Inside the acrosome are vesicles (generated by the Goigi apparatus) that cluster together and generate the cap after turning the nucleus. The acrosome contains hyaluronidase, an enzyme that helps the sperm (along with hyaluronic acid) to penetrate the egg.
• Condensation of the nucleus. The nucleus shrinks and densifies, acquiring a flat oval appearance.
• Creation of the flagellum. It is composed of a cylinder of 9 microtubules surrounding two single ones in the center. It is a structure that is located at the base of the head (formed by nucleus and acrosome) in the process of rotation of the nucleus. In turn, the flagellum is formed by: neck, middle piece and tail.
• Detachment of the cytoplasm.

Once the spermatozoa are formed they reach the seminiferous tubules. From there they will be pushed into the straight tubes, into the testis network, into the efferent cones, into the epididymal canals and, through the vas deferens, into the seminal vesicle. There they are stored until the moment of ejaculation, when the vesicle contracts and the spermatozoa exit through the ejaculatory canal into the urethra and outward.

Prognosis of the disease

Spermiogenesis is a totally natural process, it is not a disease, so it is something that occurs in all men continuously, as a period of sperm maturation. It is not something serious but totally normal. The time for a spermatogonium to become a mature spermatozoon is approximately 64 days.

Symptoms of spermiogenesis

The patient does not experience any symptoms during spermiogenesis. It is a natural process, so the patient does not notice anything.

Which specialist treats him?

The doctor who treats spermiogenesis, or who is in charge of ensuring that this process works correctly, is the specialist in Assisted Reproduction. He will check that the patient is developing spermiogenesis well and, if not, he will establish the most appropriate treatment to achieve pregnancy.