Embryology, Anatomy, and Physiology of the Male Reproductive System
Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple in Basic Urological Sciences, 2021
Spermiogenesis phaseSpermatid undergoes structural changes in the nucleus and cytoplasm to form mature spermatozoa.The round spermatid loses its cytoplasm and acquires an asymmetrical nucleus.The nucleus contains chromatin which is condensed and compacted.Acrosome and flagellum are formed.Mitochondria reorganise in the midpiece of the tail.
Golgi apparatus regulation of differentiation
C. Yan Cheng in Spermatogenesis, 2018
Spermiogenesis is a timely event defining the last phase of germ cell differentiation. It begins after the second meiotic division of spermatocytes with the formation of haploid spermatids and follows them through their metamorphosis into spermatozoa. It is subdivided into distinct steps with 19 being identified in rats; the entire process extends over 22.7 days (Figure 1.3). During spermiogenesis, many genes/proteins are expressed, some for the first time, with implications in the diverse dynamic events occurring at this time point of germ cell development. These events include elaboration of the acrosome and flagellum, nuclear condensation, and modification of specific organelles, such as the Golgi apparatus and endoplasmic reticulum (ER), leading to the formation of spermatozoa destined to be released from the seminiferous epithelium with the cytoplasmic droplet attached but the residual body detached and subject to disposal by the Sertoli cells.9,10,14,15
Gametogenesis
Frank J. Dye in Human Life Before Birth, 2019
The original spermatogonium is now four cells. The four haploid spermatids formed from the single diploid spermatogonium undergoing spermatogenesis look like typical cells at this point. However, they will now undergo a process of cell differentiation that results in the formation of cells that look anything but typical (see Figure 6.2). As the four spermatids undergo this process of spermiogenesis, they become intimately associated with the Sertoli cells, which appear to carry out some sort of “nursing” function for the differentiating cells. Note that spermiogenesis is a part of spermatogenesis—the part during which cell differentiation (spermatids to spermatozoa) occurs.
Therapeutic effect of adipose-derived mesenchymal stem cells on Cisplatin induced testicular damage in adult male albino rat
Published in Ultrastructural Pathology, 2019
Fatma Y. Meligy, Amal T. Abo Elgheed, Shymaa M. Alghareeb
Electron microscope ultrathin sections examination of stem-cell-treated group showed marked improvement of spermatogenic cells and resuming of spermatogenesis as the following: Sertoli cells were seen resting on the basement membrane with great improvement. The nucleus was large, folded, basally located with prominent nucleolus and fine granular chromatin distribution. Their cytoplasms were rich in numerous mitochondria, smooth endoplasmic reticulum and lysosomes (Figure 10a). Primary spermatocytes showed defined rounded large nuclei with fine granular chromatin and clumps of heterochromatin. The cytoplasm was rich in ribosomes and mitochondria. More or less normal intercellular junction was noticed. Longitudinal section of normal elongated spermatid was seen embedded in folds of Sertoli cells (Figure 10b). Rounded spermatids at different stages of spermiogenesis were observed. They had spherical euchromatic nuclei and a cytoplasm rich in ribosomes and peripherally arranged mitochondria. Acrosomal granule and cap were seen over one pole of the nucleus (Figure 10c). In comparison to Cisplatin-treated group, basement membrane was regular, smooth with flat myoid cells and flat tapered nuclei (Figure 10a). The interstitium showed marked improvement of Leydig cells which revealed oval to rounded indented euchromatic nuclei and a cytoplasm rich in vesicular mitochondria and lipid droplet. Macrophages were frequently detected in association with Leydig cells. They had indented euchromatic nuclei with patches of heterochromatin and their cytoplasm was rich in mitochondria and lysosomes (Figure 10d).
ADAMTS1 and ADAMTS5 metalloproteases produced by Sertoli cells: a potential diagnostic marker in azoospermia
Published in Systems Biology in Reproductive Medicine, 2019
Oya Sena Aydos, Yunus Yukselten, Sinan Ozkavukcu, Asuman Sunguroglu, Kaan Aydos
Sertoli cells of OA cases that were used as the control group, diagnosed with azoospermia due to a defect in excretory canals with no pathology in their seminiferous tubule epithelium, displayed higher levels of ADAMTS1 and ADAMTS5 proteins than NOA patients. Our data show the importance of these proteins for spermatogenesis and spermiogenesis in normal physiology. Although there is no enlightening study on this subject, it is known that MMPs as a family of ECM-degrading enzymes may have a role: i) in the migration of differentiating cells toward the lumen and ii) in the formation of blood–testis barrier by controlling Sertoli–Sertoli and Sertoli–germ cell relationships (Cheng and Mruk 2012). Animal models with silenced ADAMTS1 and ADAMTS5 can provide data that would inform about the specific roles of these proteins (Jacobsen and Wewer 2009). Moreover, the underlying cause of lower expression of these proteins in patients with NOA, compared with the controls, can be due to hormonal factors or paracrine factors localized in the testis (changes in blood supply, interaction of paracrine and autocrine factors, toxins, changes in testicular temperature, etc.) (Russel 1993; Sharpe 2000; Russel et al. 2015).
Autophagy in male reproduction
Published in Systems Biology in Reproductive Medicine, 2019
Yinci Zhu, Qingqing Yin, Dandan Wei, Zhenyu Yang, Yanzhi Du, Yi Ma
Spermatogenesis is a complex process in which successive cellular events occur sequentially in specific regions of the testis. It includes the mitosis of the spermatogonia, two meiotic divisions of the spermatocytes, spermiogenesis and spermiation. During this process, the germ cells are transported across the seminiferous epithelium by the Sertoli cells (Qian et al. 2014). The seminiferous epithelium exhibits tight junctions, gap junctions and the testis-unique junctions such as the ectoplasmic specialization (ES). ES, an actin microfilament-rich anchoring junction, includes the basal ES and apical ES. The basal ES is the constructive part of the blood-testis barrier (BTB), while the apical ES facilitates the development and maturation of the spermatid (Liu et al. 2016). After the specific knockout of Atg5 or Atg7 in the mouse Sertoli cells, the apical and basal ES were disrupted, and the cytoskeleton structure was disorganized, resulting in sperm with malformed heads and low motility. Further research revealed that a negative cytoskeleton organization regulator, PDZ and LIM domain 1 (PDLIM1), was degraded by autophagy; therefore, the deficiency of autophagy led to an abnormal accumulation of PDLIM1 and then the disorder of the cytoskeleton structure and ES assembly (Liu et al. 2016).
Related Knowledge Centers
- Acrosome
- Centriole
- Golgi Apparatus
- Spermatid
- Spermatogenesis
- Spermatozoon
- Cell Nucleus
- Mitochondrion
- Symmetry In Biology
- Axoneme