RT Journal Article
SR Electronic
T1 Sperm chemotaxis is driven by the slope of the chemoattractant concentration field
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 148650
DO 10.1101/148650
A1 H.V. Ramírez-Gómez
A1 V. Jimenez Sabinina
A1 M. Velázquez-Pérez
A1 C. Beltrán
A1 J. Carneiro
A1 C.D. Wood
A1 I. Tuval
A1 A. Darszon
A1 A. Guerrero
YR 2020
UL http://biorxiv.org/content/early/2020/01/30/148650.abstract
AB Spermatozoa of marine invertebrates are attracted to their conspecific female gamete by diffusive molecules, called chemoattractants, released from the egg investments in a process known as chemotaxis. The information from the egg chemoattractant concentration field is decoded into intracellular Ca2+ concentration ([Ca2+]i) changes that regulate the internal motors that shape the flagellum as it beats. By studying sea urchin species-specific differences in sperm chemoattractant-receptor characteristics we show that receptor density constrains the steepness of the chemoattractant concentration gradient detectable by spermatozoa. Through analyzing different chemoattractant gradient forms, we demonstrate for the first time that Strongylocentrotus purpuratus sperm are chemotactic and this response is consistent with frequency entrainment of two coupled physiological oscillators: i) the stimulus function and ii) the [Ca2+]i changes. We demonstrate that the slope of the chemoattractant gradients provides the coupling force between both oscillators, arising as a fundamental requirement for sperm chemotaxis.