کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
872135 | 910235 | 2013 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Fluid dynamic model of invertebrate sperm chemotactic motility with varying calcium inputs Fluid dynamic model of invertebrate sperm chemotactic motility with varying calcium inputs](/preview/png/872135.png)
In a marine environment, invertebrate sperm are able to adjust their trajectory in response to a gradient of chemical factors released by the egg in a process called chemotaxis. In response to this chemical factor, a signaling cascade is initiated that causes an increase in intracellular calcium (Ca2+). This increase in Ca2+ causes the sperm flagellar curvature to change, and a change in swimming direction ensues. In previous experiments, sperm swimming in a gradient of chemoattractant have exhibited Ca2+ oscillations of varying peaks and frequency. Here, we model a simplified sperm flagellum with mechanical forces, including a passive stiffness component and an active bending component that is coupled to the time varying Ca2+ input. The flagellum is immersed in a viscous, incompressible fluid and we use a fluid dynamic model to investigate emergent trajectories. We investigate the sensitivity of the model to the frequency of Ca2+ oscillations. In this coupled model, we observe that longer periods of Ca2+ oscillation corresponds to circular paths with greater drift. In contrast, shorter periods of Ca2+ oscillations corresponded to tighter search patterns. These outcomes shed light on the relation between Ca2+ oscillations and different searching trajectories and strategies that invertebrate sperm may utilize to reach and fertilize the egg in a marine environment.
Journal: Journal of Biomechanics - Volume 46, Issue 2, 18 January 2013, Pages 329–337