The conversion of the young
spermatid to the mature one (spermatogenesis), is dependent on testosterone, mainly occurring during I-VI, VII-VIII and IX-XII stages, (O'Donnell, McLachlan, Wreford, & Robertson, 1994); on the contrary to the other ones, the XIV stage, is characterized for being a step dependent of the follicle stimulating hormone (FSH), which has a maximum expression of FSH receptor in Sertoli cells (D'Souza et al., 2005).
One important stage in spermatogenesis is the meiotic division that occurs when the primary spermatocyte develops into
spermatid. Meiosis is the process of cell division through double cleavage and the reduction of the number of chromosomes.
The main characteristic of this stage was the presence of
spermatids with elongating nuclei, leading to nuclei of Sertoli cells.
The decrease in Sertoli cell number may have triggered the reduction observed in counts of the spermatogonias type A, pachytene primary spermatocytes and round
spermatids. This fact might be related to control on spermatogenesis magnitude exercised by Sertoli cell (Hess & Franga, 2005).
FW, follicular wall; Lu, lumen; Ct, connective tissue; MS, mature spermatozoa; St,
spermatid; Spz, spermatozoa; DSz, degenerative spermatozoon.
Class II Early Maturation (146.427 [+ or -] 5.694 [micro]m): Tubules in the distal, middle and proximal areas show a continuous germinal epithelium, which is 34.81 [micro]m in height, [+ or -] 1.281 consisting of germ cysts in all stages of development (spermatogonia, primary and secondary spermatocytes and
spermatids).
Testicular spermatogenesis comprises a precisely timed and synchronized development of several generations of germ cells involving spermatogonial mitosis (proliferative phase); spermatocyte in which genetic material is recombined and segregated (meiotic phase); morphological transformation of the undifferentiated
spermatids into highly specialized motile sperms (spermiogenic phase) [5].
Also it was noted in this study, a shortage in the numbers of
Spermatids and Spermatozoa inside the cavity of Seminiferous tubules and these results have been supported by [19; 24; 25; 26; 27] who have noticed a significant shortage in
Spermatids and a remarkable dampening to the process of Spermatogenesis which resulted a decrease in the concentration of Spermatozoa inside the cavity of Seminiferous tubules as a result of treatment by Cisplatin drug, also by [28] at treatment of ifosfamide drug, and [29] who noted that the treatment by the drug Gemcitabine has caused an obstruction to the process of Spermatogenesis resulting a deformation of spermatocytes as well as Spermatozoa, plus a shortage in their number.
Secondary spermatocytes were rarely seen as they quickly changed to
spermatids. Both round and elon-gated
spermatids were seen.
The mouse cells produced were technically "
spermatids" - undeveloped sperm that lack tails and cannot swim.
During this process, the germ line stem cells embedded in the supporting Sertoli cells of the seminiferous tubules divide mitotically to expand the pool of spermatogonia; after two meiotic divisions, these actions will give rise to spermatocytes and haploid
spermatids. The
spermatids subsequently undergo a morphological and molecular remodeling process, known as spermiogenesis, during which the head, middle piece, and flagellum of the spermatozoa differentiate (Eddy, 2006).