Selection of the genetic material necessary to fertilize the ovum – Points of view-DOI:10.37072/JCS.2021.04.03

Univ. Prof. Bogdan MARINESCU – 1
Valentin NIȚESCU – 2

1. Department of Infertility, Clinical Hospital of Obstetrics- Gynecology “Prof. Dr. Panait Sîrbu”, Giulești Maternity Hospital, MD, Ph.D
2. Hôpital Universitaire “Pitié-Salpêtrière”, Service de Chirurgie Générale, Viscérale et Endocrinienne, Faculté de Médecine, Sorbonne Université (Paris), MD

The testicular Leydig cells synthesize androgenic hormones and are sensitive to the stimulation of gonadotropic hormones. The Sertoli cells located in the seminiferous tubules are the site of spermatogenesis.
The pituitary gland, by luteinizing hormone (LH) production, stimulates the synthesis and secretion of testosterone by Leydig cells, and by follicle-stimulating hormone (FSH) acts, synergic with testosterone, on Sertoli cells, thus stimulating the spermatogenesis (1).
The transition of spermatogonia in the maturation process is performed every 16 days, and the transition from spermatogonic stem cells to mature sperm cells is accomplished within 75 days (2).
By mitotic division, spermatogonia forms diploid spermatocytes, which, through meiosis, transform into haploid spermatids, which contain 23 chromosomes, which will later fuse to form a zygote. (3)
Through the process of spermiogenesis, the spermatids mature by condensing their nucleus thus forming the flagellum and acrosome. The spermatozoon reaches the seminiferous tubules in the epididymis, where, progressively, their maturation continues, within 2-6 days, in the vas deferens (4).
The spermatic fluid is a complex product, consisting of seminal plasma and sperm cells. White-yellowish seminal plasma with a specific, pungent odor, consists of secretions from the epididymis, vas deferens (approximately 10%), seminal vesicles (approximately 55%), prostate (approximately 25%), bulbourethral glands and testicular secretions, all these ensuring the sperm survival and motility.