Reorganization of the Flagellum Scaffolding Induces a Sperm Standstill Required for Fertilization

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.06.22.546073v1?rss=1 Authors: Jablonski, M., Luque, G. M., Gomez-Elias, M., Sanchez-Cardenas, C., Xu, X., de la Vega-Beltran, J. L., Corkidi, G., Linares, A., Abonza, V., Krapf, D., Krapf, D., Darszon, A., Guerrero, A., Buffone, M. G. Abstract: Mammalian sperm delve into the female reproductive tract to fertilize the female gamete. Within the midpiece of the sperm flagellum lies a cortical network of actin that is arranged as a double helix sheltering the mitochondrial sheath. This work demonstrates that the actin network of the midpiece undergoes structural changes that result in motility cessation. This structural modification is accompanied by a decrease in diameter of the midpiece and is driven by intracellular calcium changes that occur concomitant with a reorganization of the actin helicoidal cortex. Although midpiece contraction may occur in a subset of cells that undergo acrosomal exocytosis, live-cell imaging during in vitro fertilization showed that the midpiece contraction is required for motility cessation during the fusion process. These findings provide the first evidence of the F-actin network's role in regulating sperm motility, adapting its function to meet specific cellular requirements during fertilization. These findings provide the first evidence of the F-actin network's role in regulating sperm motility, adapting its function to meet specific cellular requirements during fertilization, and highlighting the broader significance of understanding sperm motility. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC