by Keyword: Spermatozoa

Zhang, KX, Klingner, A, Le Gars, Y, Misra, S, Magdanz, V, Khalil, ISM, (2023). Locomotion of bovine spermatozoa during the transition from individual cells to bundles Proceedings Of The National Academy Of Sciences Of The United States Of America 120, e2211911120

Various locomotion strategies employed by microorganisms are observed in complex biological environments. Spermatozoa assemble into bundles to improve their swimming efficiency compared to individual cells. However, the dynamic mechanisms for the formation of sperm bundles have not been fully characterized. In this study, we numerically and experimentally investigate the locomotion of spermatozoa during the transition from individual cells to bundles of two cells. Three consecutive dynamic behaviors are found across the course of the transition: hydrodynamic attraction/repulsion, alignment, and synchronization. The hydrodynamic attraction/repulsion depends on the relative orientation and distance between spermatozoa as well as their flagellar wave patterns and phase shift. Once the heads are attached, we find a stable equilibrium of the rotational hydrodynamics resulting in the alignment of the heads. The synchronization results from the combined influence of hydrodynamic and mechanical cell-to-cell interactions. Additionally, we find that the flagellar beat is regulated by the interactions during the bundle formation, whereby spermatozoa can synchronize their beats to enhance their swimming velocity.

JTD Keywords: behavior, cilia, collective locomotion, collective motion, competition, flagellar propulsion, hydrodynamics, motility, propulsion, sperm cooperation, tracking, Collective locomotion, Flagellar propulsion, Flagellar synchronization, Spermatozoa bundle

Soler, PMI, Hidalgo, C, Fekete, Z, Zalanyi, L, Khalil, ISM, Yeste, M, Magdanz, V, (2022). Bundle formation of sperm: Influence of environmental factors Frontiers In Endocrinology 13, 957684

Cooperative behaviour of sperm is one of the mechanisms that plays a role in sperm competition. It has been observed in several species that spermatozoa interact with each other to form agglomerates or bundles. In this study, we investigate the effect of physical and biochemical factors that will most likely promote bundle formation in bull sperm. These factors include fluid viscosity, swim-up process, post-thaw incubation time and media additives which promote capacitation. While viscosity does not seem to influence the degree of sperm bundling, swim-up, post-thaw migration time and suppressed capacitation increase the occurrence of sperm bundles. This leads to the conclusion that sperm bundling is a result of hydrodynamic and adhesive interactions between the cells which occurs frequently during prolonged incubation times.Copyright © 2022 Morcillo i Soler, Hidalgo, Fekete, Zalanyi, Khalil, Yeste and Magdanz.

JTD Keywords: acrosome reaction, adhesion, bundling, capacitation, cell-cell interaction, cooperation, cooperative behaviour, fertilization, mammals, membrane, motility, progesterone, sperm competition, sperm migration, sperm selection, Bovine spermatozoa, Bundling, Cell-cell interaction, Cooperative behaviour, Sperm competition, Sperm migration, Sperm selection, Spermatozoa

Chattopadhyay, P, Magdanz, V, Hernandez-Melia, M, Borchert, KBL, Schwarz, D, Simmchen, J, (2022). Size-Dependent Inhibition of Sperm Motility by Copper Particles as a Path toward Male Contraception Advanced Nanobiomed Research 2, 2100152

Effective inhibition of sperm motility using a spermicide can be a promising approach in developing non-invasive male contraceptive agents. Copper is known to have contraceptive properties and has been used clinically for decades as intrauterine contraceptive devices (IUDs) for contraception in females. Beyond that, the spermicidal use of copper is not explored much further, even though its use can also subdue the harmful effects caused by the hormonal female contraceptive agents on the environment. Herein, the size, concentration, and time-dependent in vitro inhibition of bovine spermatozoa by copper microparticles are studied. The effectivity in inhibiting sperm motility is correlated with the amount of Cu2+ ions released by the particles during incubation. The copper particles cause direct suppression of sperm motility and viability upon incubation and thereby show potential as sperm-inhibiting, hormone-free candidate for male contraception. In addition, biocompatibility tests using a cervical cell line help optimizing the size and concentration of the copper particles for the best spermicidal action while avoiding toxicity to the surrounding tissue.

JTD Keywords: Bovine spermatozoa, Clinical-trial, Copper, Human-spermatozoa, Ions, Male contraception, Metallic copper, Microparticles, Progestins, Sperm motility, Sperm viability, Spermicide, Viability