Genetics and exercise: an introduction
Adam P. Sharples, James P. Morton, Henning Wackerhage in Molecular Exercise Physiology, 2022
It is important to understand the distinction between germ cells and somatic cells. Male and female germ cells, sperm and oocyte, respectively, are termed gametes. A mature germ cell has only 22 autosomes plus one sex chromosome (i.e. 23 chromosomes in total) in its nucleus instead of the full complement of 46 chromosomes seen in somatic cells (i.e. body cells or non-germ cells). A germ cell containing 23 chromosomes is said to be “haploid”, whereas normal somatic cells contain a “diploid” set of chromosomes. When a haploid sperm and a haploid oocyte fuse, they form a diploid, fertilized oocyte, termed zygote, which is the first cell of the new organism. It has 2 × 22 autosomes plus either two X chromosomes (XX, a female) or an X and a Y (XY, a male) chromosome.
Equine Semen Preservation: Current and Future Trends
Juan Carlos Gardón, Katy Satué in Biotechnologies Applied to Animal Reproduction, 2020
The ejaculate is a liquid suspension composed of sperm and seminal plasma, which comprised a complex mixture of secretions (fructose, sorbitol, ascorbic acid, lactic acid, citric acid, proteins, enzymes, vitamins, and hormones). Seminal plasma-derived primarily from the epididymis and accessory sex glands of the male. It participates in the final sperm maturation, modifies spermatic membrane surface, besides acts as a vehicle for the ejaculated sperm and protects the spermatozoa during the female reproductive tract transport (Töpfer-Petersen et al., 2000). In stallion, the seminal plasma is normally separated from the semen during the cryopreservation process, since it has proved to be a harmful medium because decrease the percentage of sperm with progressive motility (Pickett et al., 1975; Jasko et al., 1992). The ejaculate should not be exposed to mechanical damage, light, cold, or heat and the equipment in contact with the sperm must be tempered, dry, clean, and free of toxic residues. After ejaculation, the semen will be kept at 30/32ºC before the seminal evaluation and subsequent dilution (Brinsko and Varner, 1992).
Radiation Damage of the Reproductive Organs
Kedar N. Prasad in Handbook of RADIOBIOLOGY, 2020
The processes of the formation of sperm are referred to as spermatogenesis. The highly proliferating spermatogonia line the seminiferous tubules and give rise to primary and secondary spermatocytes, which then form spermatids. The spermatids do not divide. Each spermatid matures into one spermatozoon. On the criterion of cell death, spermatogonia are most radiosensitive, whereas spermatids and spermatozoa are most radioresistant, but the possibility of genetic damage is high for all cellular elements. The interstitial cells that produce male hormone are also highly radioresistant. Therefore, men exposed at a sterilizing dose (500–600 rads) of radiation retain their fertility and produce seminal and prostatic fluid without sperm for a while. After irradiation, the testis becomes smaller and softer, and may become sterile. However, no change in the beard, voice, or social behavior has been observed.
Mapping the human sperm proteome – novel insights into reproductive research
Published in Expert Review of Proteomics, 2023
Mika Alexia Miyazaki, Raquel Lozano Guilharducci, Paula Intasqui, Ricardo Pimenta Bertolla
During their journey through the female genital tract, sperm undergo functional changes in order to achieve successful fertilization. Among these processes, spermatozoa capacitation has been studied from a proteomics point of view to understand the protein pattern transition in this event. After capacitation medium (CAP) incubation, increased proteins mainly involved in fertilization, sperm motility, and energy production were observed. Between 11 proteins identified, 9 were decreased, such as AKAP3, AKAP4, ODF2, Phosphoglycerate kinase 2 (PGK2), and Radial spoke head 1 homolog (RSPH1), all of them involved in PKA-dependent signaling process and consequently in supporting sperm motility [55,70]. In order to catalyze the first ATP-generating step in the central metabolic pathway of glycolysis to promote = tail movement, PGK2 protein is necessary. Located mainly in the principal piece of the flagellum, in male Pgk2−/− mice, sperm function, and motility were found to be altered, what may be the reason for the low expression [82]. On the other hand, five proteins, mainly from signaling, protein degradation, and vesicular trafficking processes were increased [70]. Moreover, a study incubating sperm with increasing concentrations of sperm plasma membrane-associated proteins (SMAP) showed about 12 proteins associated with the sperm surface. Of these, 22% are associated with protein binding and 7% with endopeptidase inhibitor activity, and they can also affect tyrosine phosphorylation, which, in turn, affects sperm hyperactivated motility [83].
Fertility preservation and realignment in transgender women
Published in Human Fertility, 2023
Erna Bayar, Nicola J. Williams, Amel Alghrani, Sughashini Murugesu, Srdjan Saso, Timothy Bracewell-Milnes, Meen-Yau Thum, James Nicopoullos, Philippa Sangster, Ephia Yasmin, J. Richard Smith, Stephen Wilkinson, Allan Pacey, Benjamin P. Jones
Transgender women are now presented with viable options regarding the preservation of their reproductive potential, as summarised in Figure 2. Fertility preservation can take place prior to transition, utilising sperm cryopreservation, with subsequent in-vitro fertilisation (IVF) or intra uterine insemination (IUI) with a female partner or surrogate using donor oocytes. However, sperm cryopreservation is not possible in those wishing to undergo treatment prior to the onset of sexual maturity, owing to the absence of mature sperm. In this population, electroejaculation and testicular biopsies can be carried out in early puberty before virilisation (Parikh et al., 2021; Peri et al., 2021). Each option presents advantages and disadvantages, which vary depending on individual circumstance. To avoid compromising future reproductive aspirations and risk involuntary childlessness, it is essential extensive reproductive counselling takes place prior to hormonal or surgical therapy (Martinez, 2017). The key to optimising patient-centred care and shared decision-making is the provision of accurate, supportive, and empowering counselling. It should explore all available options to ameliorate the adverse, and potentially irreversible impact of hormonal and surgical treatment on fertility. It should also be individualised, respecting differences in priorities and preferences among patients who may legitimately privilege speedy transition over fertility preservation and/or be dissuaded by the experimental or invasive nature of certain options (Chen et al., 2017, 2018; Nahata et al., 2017; Pang et al., 2020).
Atrazine neural and reproductive toxicity
Published in Toxin Reviews, 2022
Hamidreza Sadeghnia, Sara Shahba, Alireza Ebrahimzadeh-Bideskan, Shabnam Mohammadi, Amir Mohammad Malvandi, Abbas Mohammadipour
Sperm is produced from germinal cells through spermatogenesis. The primary cell involved in spermatogenesis is spermatogonia (Fani et al. 2018). Fani et al. (2018) showed that atrazine dysregulates the process of spermatogenesis (Fani et al. 2018). This study revealed that atrazine exposure resulted in increased apoptosis in spermatogonia and primary spermatocytes and reduced sperm quality in mice. Another study reported that atrazine administration (300 mg/kg) to rats decreases sperm motility and counts by 25.8% and 27.6%, respectively (Kale et al. 2018). An increase in apoptotic cells number may be due to oxidative stress induced by atrazine. According to Kale et al. (2018), atrazine-induced oxidative damage in testis is associated with cyclooxygenase-2 (COX-2), an enzyme involved in various pathological conditions, and able to induce oxidative stress (Chae et al. 2008, Kale et al. 2018). Kale et al. (2018) investigated the effect of COX-2 inhibitor against atrazine-induced toxicity and observed histopathological improvement of testis in treated rats, which indicates that COX-2 plays a crucial role in atrazine-induced damages.
Related Knowledge Centers
- Flagellum
- Pollen
- Seminiferous Tubule
- Sexual Reproduction
- Spermatogenesis
- Spermatozoon
- Gamete
- Cell
- Anisogamy
- Motility