Reproduction Abstracts

Human sperm use different behaviours for different aspects of sperm transport and fertilisation. We have investigated the effects of preparation method (density gradient method and direct swim-up) on sperm behaviour and manipulated Ca2+ signalling (the primary regulator of sperm motility) to induce different behaviours and assessed their effects on penetration of human sperm through viscous medium (methylcellulose).Cells prepared by swim-up pe...

Catsper is a Ca2+ permeable ion channel in the principal piece of the sperm flagellum that is crucial in regulation of motility. It is multimodally sensitive, being activated by voltage, pHi and diverse agonists including progesterone. Elevation of pHi and progesterone both shift voltage-sensitivity of the channel to more negative potentials and thus may act synergistically to enhance Ca2+-influx.1 However, intracellular alkalinisation of human...

Ca2+ signalling is critical for regulation of sperm motility. [Ca2+]i oscillations, which may underlie observed ‘switching’ of sperm behaviors, occur in human spermatozoa stimulated with progesterone. Our work aimed to investigate the potential contribution of changes in membrane potential, leading to cyclical activation of voltage dependent Ca2+-influx pathways, to [Ca2+]i oscillations. Spermatozoa we...