Mammalian Sperm Motility: Observation and Theory

TLDR

Mammalian sperm motility is increasingly important for addressing human infertility and enhancing animal breeding, yet understanding the flagellum’s mechanics during migration through the female reproductive tract remains limited and requires improved modeling. The authors aim to summarize current theoretical studies and highlight how fluid and continuum dynamics, combined with imaging, can yield novel insights into sperm mechanics during their journey to the egg, while outlining future challenges. The study reviews theoretical models that integrate imaging and continuum dynamics to investigate sperm motility and identifies challenges for future observational and theoretical work.

Abstract

Mammalian spermatozoa motility is a subject of growing importance because of rising human infertility and the possibility of improving animal breeding. We highlight opportunities for fluid and continuum dynamics to provide novel insights concerning the mechanics of these specialized cells, especially during their remarkable journey to the egg. The biological structure of the motile sperm appendage, the flagellum, is described and placed in the context of the mechanics underlying the migration of mammalian sperm through the numerous environments of the female reproductive tract. This process demands certain specific changes to flagellar movement and motility for which further mechanical insight would be valuable, although this requires improved modeling capabilities, particularly to increase our understanding of sperm progression in vivo. We summarize current theoretical studies, highlighting the synergistic combination of imaging and theory in exploring sperm motility, and discuss the challenges for future observational and theoretical studies in understanding the underlying mechanics.