How long does it take for sperm to mature? We need to understand it from the formation process

If sperm enters the uterus and combines with the egg cell to achieve successful conception, the maturity of sperm plays a key role. So, how long does it take for sperm to mature?

1. Spermatogonial cell proliferation and division stage:

The most primitive stage of sperm is called spermatogonia, which is the stem cell that produces sperm and is located in the seminiferous epithelium of the seminiferous tubules. Initially, spermatogonia proliferate in the form of mitosis, 1 splits into 2, 2 becomes 4. After 6 divisions, 1 spermatogonia proliferates into 64, which are called primary spermatocytes.

2. Spermatocytes undergo meiosis to become sperm cells:

The primary spermatocytes continue to divide. However, this time it is meiosis, that is, one primary spermatocyte divides into two secondary spermatocytes, but it is different from the proliferation division of spermatogonia because the chromosomes in the cell nucleus are not replicated. Therefore, each secondary spermatocyte carries only half of the original number of chromosomes, that is, 23 chromosomes, including one sex chromosome. The cell volume is also smaller than that of the primary spermatocyte. Following this process, the secondary spermatocyte undergoes another maturation division and becomes two spermatocytes. As a result, one primary spermatocyte divides into four spermatocytes, each of which carries a haploid number of chromosomes. At this point, one spermatogonia becomes 256 sperm cells.

3. Sperm formation stage:

At the same time as the above-mentioned cell division, the sperm cells have gradually moved closer to the lumen of the seminiferous tubules. At this time, the sperm cells are still developing, but they no longer divide. However, they have undergone complex changes in morphology and become sperm with heads and tails, and enter the lumen. At this time, the development process of sperm in the testis is completed, which takes about 64 days. In the process of sperm formation, the supporting cells located in the epithelium of the seminiferous tubules play an important role in support, protection and nutrition. The supporting cells also secrete a globulin that specifically binds to androgens, thereby making the androgen concentration in the seminiferous tubules much higher than the concentration in the blood. Only in this suitable microenvironment can spermatogenic cells differentiate into sperm.

The sperm then travels along the seminiferous tubules into the epididymis, where it stays for about 2-3 weeks before developing into mature sperm that can move and fertilize. Therefore, it takes about 90 days for a spermatogonia to develop into a mature sperm.