Cytoskeletons (F-actin) and spermatogenesis
C. Yan Cheng in Spermatogenesis, 2018
Spermatozoa are produced during the complex and elegant process of spermatogenesis. These specialized cells arise from immature diploid spermatogonia, which undergo meiosis to produce haploid gametes. The sperm structure develops during spermiogenesis, where a round haploid germ cell (round spermatid) is transformed into a spermatozoon by the development of a motile cilium, a streamlined nucleus, and an acrosomal cap required for fertilization. All aspects of male germ cell development are supported by the somatic Sertoli cell; this large and structural complex cell simultaneously supports multiple germ cells at different phases of development, providing both the structural and nutritional support required to execute the spermatogenic program. Spermatogenesis is highly dynamic and precisely controlled in space and time and is accompanied by extraordinary changes in each cell’s cytoskeleton. This chapter will address the role of a particular cytoskeletal component, actin, in spermatogenesis.
Semen Analysis
Botros Rizk, Ashok Agarwal, Edmund S. Sabanegh in Male Infertility in Reproductive Medicine, 2019
IgA antibodies have a more critical relevance in male infertility than IgG. Patients who are presenting with IgA antibodies have a reduced chance of natural pregnancies [22,23]. IgA antibodies mainly have agglutinating properties and rarely occur without the presence of IgG antibodies. These antibodies are secreted by the accessory glands; seminal vesicles, prostate gland, and the bulbourethral glands. They are present on the spermatozoa and occasionally in the seminal plasma but are absent in the serum. When performing the Direct SpermMar Test for IgA a fresh semen sample or spermatozoa is isolated from the seminal plasma by one cycle of suspension, centrifugation, and resuspension in media. A 10-µL spermatozoa suspension is mixed with 10 µL of antihuman anti-IgA suspension and mixed [21]. A coverslip is placed on top, and the slide is placed in a humidified chamber for 3 minutes. The technologist will observe the wet prep slide with a coverslip under 40× objective and read 100 motile sperm [21]. The bead-binding site on the spermatozoa (sperm head, tail, midpiece, or total sperm) is also recorded.
The Plasma Membrane of the Spermatozoon
Sek Wen Hui in Freeze-Fracture Studies of Membranes, 1989
As with the sperm head, the flagellum of mammalian spermatozoa can be divided into several distinct regions possessing specific structural characteristics. These include the neck, middle piece, principal piece, and end/or terminal piece. The plasma membrane enveloping these regions appears, at least in part, to be differentiated according to the nature of underlying structures. Thus, although the axonemal components such as the 9 + 2 microtubules course almost the entire length of the flagellum, it seems rather to be the immediate submembranous structures which influence plasma membrane ultrastructure and function. Sperm flagellar membranes from more “primitive” organisms such as the sea urchin, do not show such differences in organization along their lengths, nor are there significant changes in sub-membranous organelles. The base of the flagellum in sperm from such organisms has been shown to possess a “ciliary necklace”, a strand or strands of IMPs around the base of the flagellum (Cosson and Gulik17). Other than this formed structure, the basic pattern is that of randomly scattered IMPs.
Repeated administrations of Mn3O4 nanoparticles cause testis damage and fertility decrease through PPAR-signaling pathway
Published in Nanotoxicology, 2020
Xiao Zhang, Zongkai Yue, Haijun Zhang, Lu Liu, Xiaomeng Zhou
It is well known that spermatozoa are produced from spermatogonial stem cells by a series of process involving mitosis, meiosis and cellular differentiation, and spermatogenesis is essential for sexual reproduction (Oliva and Castillo 2011). Meanwhile, spermatogenesis process is subjected to the neuroendocrine hypothalamic-pituitary-gonadal (HPG) axis (Huleihel and Lunenfeld 2004). In addition, hormones secreted by hypothalamus are transported to the pituitary gland via the blood and then induce the production and secretion of gonadotropins which in turn are transported to testes by the blood (Kong et al. 2014). LH stimulates the Leydig cells in the testes to synthesize and secrete the testosterone (Li et al. 2013). FSH and T stimulate Sertoli cells to produce androgen binding protein and improve the formation of the BTB, meanwhile, FSH and T could support and nourish the sperm cells during their maturation (Sofikitis et al. 2008). In this study, the serum T, FSH, and LH levels in serum of rats were determined to investigate the effect of Mn3O4-NPs on sex hormones. The serum T and FSH levels were significantly decreased in Mn3O4-NPs-120 d compared with those in the Mn3O4-NPs-0 d and Mn3O4-NPs-60 d, indicating that the serum T and FSH were suppressed in a time-dependent manner after administrated with Mn3O4-NPs. All results suggest that Mn3O4-NPs can disturb the normal HPG axis function which correlated with the malfunction in spermatogenesis and male infertility.
Microfluidic sperm selection yields higher sperm quality compared to conventional method in ICSI program: A pilot study
Published in Systems Biology in Reproductive Medicine, 2021
Fatemeh Anbari, Mohammad Ali khalili, Abdul Munaf Sultan Ahamed, Esmat Mangoli, Ali Nabi, Fatemeh Dehghanpour, Mojdeh Sabour
We measured the sperm parameters with more advanced methods as MSOME at x6600 magnification, before and after both sperm preparation methods (DSU and MSS). The spermatozoa were classified according to the degree of vacuolization, shape, and size of midpiece and head (Mangoli and Khalili 2020). Although, both methods showed a positive effect on sperm quality, the MSS significantly selected Class I spermatozoa (good quality) more than DSU. The MSS method allows for the selection of sperm with low sperm DNA fragmentation (SDF). These results are consistent with previous studies (Shirota et al. 2016). Similar to our study, it was designed an effective approach based on MSS in an ICSI dish. The authors reported their method was provided sperm cells with better maturity and head morphologhy compared to DCG (De Martin et al. 2017). Numerous studies have reported that high SDF is associated with pregnancy loss after IVF and ICSI (Virro et al. 2004). In fact, the SDF threshold value is unclear, but it is believed that pregnancy is difficult to achieve when the SDF value exceeds 27%–30% (Lin et al. 2008). Reducing the preparation time and eliminating the centrifugation step may minimize sperm exposure to concentrated ROS and prevent DNA fragmentation (Yelumalai et al. 2012).
Spermatogenesis and steroidogenesis disruption in a model of metabolic syndrome rats
Published in Archives of Physiology and Biochemistry, 2023
Dalila Rahali, Yosra Dallagi, Emmeline Hupkens, Gregory Veegh, Kathleen Mc Entee, Monia El Asmi, Saloua El Fazaa, Narges El Golli
Sperm morphological alterations were evaluated and examined under a light microscope (100x objective). Sperm samples were obtained from the cauda of one single epididymis of the two groups of rats. One drop of the solution was smeared onto a glass slide and allowed to air-dry. The smears were stained by the spermo-EOSINE-RAL andspermo-BLEU-RAL and fixed by spermo-FIX-RAL. Sperm morphological alterations were evaluated and examined under light microscope and the percentage of abnormal spermatozoa was obtained. The classification of morphological abnormalities consisting of the head and tail of the spermatozoa was performed according to the modified descriptions, based on (Filler 1993) and (Miranda-Spooner et al.2016) adapted for the experimental model used. The abnormal characteristics considered were as follows: (1) shape of spermatozoa head; (2) defects in tails; (3) multiple abnormalities in head and tails.