What is spermatogenesis? – Definition and phases of spermatogenesis
To fully understand reproduction, we must carefully review certain aspects that are part of this process. As is spermatogenesis, and all the procedures that it entails that have a final objective, to achieve the formation of the spermatozoon.. Therefore, keep reading to understand this topic more fully.
What is the definition of spermatogenesis?
Its definition is based on the process by which spermatozoa are created, which are male gametes, male sex cells. Its objective is to carry out the fertilization of the ovum in order to give way to an embryo, according to oogenesis.
When we talk about human cells we have 46 chromosomes, with the exception of gametes. Whether they are female or male, they have 23, because when they get together they collect the specific amount. This operation is essential to fully understand all the phases that lead to the formation of spermatozoa.
When the spermatozoon reaches the ovum, a fusion of both where it is generated a zygote. From which what is known as an embryo will develop, which will later be a fetus. Until becoming a baby, all this thanks to the fertilization race that the sperm must go through.
This process is an essential part of the evolution of sperm life. And with it the whole reproduction procedure takes place. Where spermatogenesis includes the journey that the gamete must pass in order to reach fertilization.
How does spermatogenesis occur?
Part of a process that forms cell differentiation, which leads to the production of sperm. This develops within the testis, specifically in the seminiferous tubules. When being created, the gametes move through the center of this and travel to the epididymis. Which is the upper part of the testicles, where the final maturation will develop to be expelled.
The process of spermatogenesis occurs when the man reaches his sexual maturity, this specifically in the stage of puberty. Where the spermatozoa begin to be produced starting from the germ cells that are primordial to the male. This through certain mechanisms such as mitosis and meiosis that occur in the testicles.
The cells that are involved in spermatogenesis initiate the process from a diploid chromosome set. This in order to end up in another that will be haploid in the sperm. which would be the male reproductive cell, the gamete, destined to the fertilization of the ovum. It is also called or known as the process of spermatogonia.
What are the stages of spermatogenesis?
The duration of these phases includes between 60 to 75 days, and we can divide them into the complete cycle. Which are:
- proliferative: This is given from the stem cells where the spermatogonia that are type a are founded. Also known as diploids, which through mitosis, cell division, gives way to others of this type. These have a minimum number that differ from spermatocytes that are of the first level b.
- meiotic phase: Here we fully enter into what is known as spermatogenesis. It is based on meiosis, which is cell division in which half of the genetic information is reduced. Here the initial spermatocyte, which has 46 chromosomes, is going to divide into two second-level ones.
Which in turn will separate into two cells each with 23 chromosomes, which are the haploid spermatids. So we will have as a result that the main spermatocyte will form four spermatids. During this cycle there will be a separation of the chromosomes which are homologues for a recombination. The fundamental part of the creation of genetic diversity occurs in two specific stages:
- Meiosis I: each of the primary spermatocytes that are diploid separates into two haploid secondary spermatocytes.
- Meiosis II: Secondary spermatocytes will divide into two spermatids that are haploid. In order to obtain a count of four cells starting from the first. It is during this process that we can observe that the formed spermatozoon begins to be created, which presents the flagellum.
Finally, we have spermatogenesis, which represents the final step, which is maturation. At this certain time is where there is an increase in the size of the tail and head. DNA is already contained, which tapers off and becomes a pointed shape. In order to cross the zona pellucida that proceeds to the ovule.
The formation of the acrosome is also lengthened, as well as its nucleus, during this particular process there is a controlled time. So if there is any variation It can indicate the existence of infertility. So it is recommended to go to the hospital to carry out the corresponding examinations.
Why is spermatogenesis meiosis?
When we talk about meiosis, it corresponds to a cell division where gametes with a haploid chromosome endowment are formed. Therefore, with respect to spermatogenesis, this represents the second phase. where the primary spermatocytes that are 2n they will divide to become round spermatids n.
Being one of the longest stages, the result is four cells that are haploid of sperm. This is why when we talk about spermatogenesis, we are also talking about meiosis.
Although they become complex processes, they are essential when it comes to having knowledge about reproduction. And of course, everything that entails, because they are a series of elements. Which have a common goal, which is sperm development so that it can fertilize the ovum and from there create life.