Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
Int J Mol Sci
2021 Aug 24;2217:. doi: 10.3390/ijms22179104.
Show Gene links
Show Anatomy links
In Silico Reconstruction of Sperm Chemotaxis.
Naruse M
,
Matsumoto M
.
???displayArticle.abstract???
In echinoderms, sperm swims in random circles and turns in response to a chemoattractant. The chemoattractant evokes transient Ca2+ influx in the sperm flagellum and induces turning behavior. Recently, the molecular mechanisms and biophysical properties of this sperm response have been clarified. Based on these experimental findings, in this study, we reconstructed a sperm model in silico to demonstrate an algorithm for sperm chemotaxis. We also focused on the importance of desensitizing the chemoattractant receptor in long-range chemotaxis because sperm approach distantly located eggs, and they must sense the chemoattractant concentration over a broad range. Using parameters of the sea urchin, simulations showed that a number of sperm could reach the egg from millimeter-order distances with desensitization, indicating that we could organize a functional sperm model, and that desensitization of the receptor is essential for sperm chemotaxis. Then, we compared the model with starfish sperm, which has a different desensitization scheme and analyzed the properties of the model against various disturbances. Our approach can be applied as a novel tool in chemotaxis research.
Figure 1. Design of sperm models. (A) Conceptual diagram of modeled sperm. Sperm movement was chosen between the circular motion and turn, depending on (Chemoattractant) and (GC). B and D: Sperm curvatures of sea urchin (B) and starfish (D) in turn mode. The y-axis indicates the curvature in relative change to the circular-motion mode. The x-axis is a time series in 60 ms frames. C and E: Sperm movement pattern of turn mode in the sea urchin model (C) and starfish model (E). The colors of the tracks correspond to the colors of lines B and D. (F) An example of the shape of the (Chemoattractant) gradient defined within a radius of 5000 μm. The z-axis indicates (Chemoattractant) at each point calculated in the 2D surface represented as an x-y plane, where the egg is located at the origin with (Chemoattractant)s = 0.1 nM.
Figure 2. Results of simulations with the sea urchin model. (A) Summary of simulation results. The x-axis indicates the distance between the sperm start-point and the center of the egg, and egg-arrival rates of sperm from these points are shown as the longitudinal axis (n = 10,000). The blue symbols represent the results of the desensitization model, and the red symbols represent the results of a model in which the desensitization function is frozen. The length of the simulation was 30 min. (B) Magnification of a part of A. (C) Representative trajectories in the simulation. The black circle at the center indicates the egg, and the sperm started swimming from the four gray circles. Trajectories 1 and 2, 3 and 4, 5 and 6, and 7 and 8 start from the same points. Trajectories 2, 4, 6, and 8 show successful examples, whereas the others represent failures.
Figure 3. Result of simulations with starfish model. (A,B) Summary of the simulation results with the starfish model. The axes and colors are the same as in Figure 2A,B. (C) Representative trajectories in the simulation using the starfish model. The black circle indicates the egg, and the sperm started from the four gray circles. Trajectories 1 and 2, 3 and 4, 5 and 6, and 7 and 8 start from the same points. Trajectories 2, 4, 6, and 8 show successful examples, whereas the others represent failures.
Figure 4. Further analysis of models. (A–F) Summarized graphs of simulations with modification in parameters and the threshold for [cGMP]i, K1/2, and [Chemoattractant]s. The y-axis shows the egg-arrival rates of sperm (n = 10,000), with the modification in each parameter shown as the abscissa axis. (A,C,E) correspond to the sea urchin models. (B,D,F) represent the starfish models. Green lines indicate the original values of the parameters. (G,H) Effects of physical disturbances in the sea urchin model (G) and starfish model (H). The y-axis shows the egg-arrival rates of sperm (n = 10,000), with the frequency of sine-wave oscillation shown as the x-axis. The broken line represents 0.01 Hz, and the arrowhead in G indicates a local maximum at 100 Hz.
Alvarez,
The rate of change in Ca(2+) concentration controls sperm chemotaxis.
2012, Pubmed,
Echinobase
Alvarez,
The rate of change in Ca(2+) concentration controls sperm chemotaxis.
2012,
Pubmed
,
Echinobase
Alvarez,
The computational sperm cell.
2014,
Pubmed
Brenker,
The CatSper channel: a polymodal chemosensor in human sperm.
2012,
Pubmed
Brokaw,
Calcium-induced asymmetrical beating of triton-demembranated sea urchin sperm flagella.
1979,
Pubmed
,
Echinobase
Böhmer,
Ca2+ spikes in the flagellum control chemotactic behavior of sperm.
2005,
Pubmed
,
Echinobase
Bönigk,
An atypical CNG channel activated by a single cGMP molecule controls sperm chemotaxis.
2009,
Pubmed
,
Echinobase
Ernesto,
CRISP1 as a novel CatSper regulator that modulates sperm motility and orientation during fertilization.
2015,
Pubmed
Guerrero,
Strategies for locating the female gamete: the importance of measuring sperm trajectories in three spatial dimensions.
2011,
Pubmed
Jikeli,
Sperm navigation along helical paths in 3D chemoattractant landscapes.
2015,
Pubmed
,
Echinobase
Kaupp,
The signal flow and motor response controling chemotaxis of sea urchin sperm.
2003,
Pubmed
,
Echinobase
Kawase,
Guanylyl cyclase and cGMP-specific phosphodiesterase participate in the acrosome reaction of starfish sperm.
2004,
Pubmed
,
Echinobase
Kromer,
Decision making improves sperm chemotaxis in the presence of noise.
2018,
Pubmed
,
Echinobase
MacKay,
Computer simulation of aggregation in Dictyostelium discoideum.
1978,
Pubmed
Matsumoto,
Regulation of the starfish sperm acrosome reaction by cGMP, pH, cAMP and Ca2+.
2008,
Pubmed
,
Echinobase
Naruse,
Acrosome reaction-related steroidal saponin, Co-ARIS, from the starfish induces structural changes in microdomains.
2010,
Pubmed
,
Echinobase
Naruse,
Novel conserved structural domains of acrosome reaction-inducing substance are widespread in invertebrates.
2011,
Pubmed
,
Echinobase
Niikura,
Protein kinase A activity leads to the extension of the acrosomal process in starfish sperm.
2017,
Pubmed
,
Echinobase
Nishigaki,
Structure and function of asterosaps, sperm-activating peptides from the jelly coat of starfish eggs.
1996,
Pubmed
,
Echinobase
Nishigaki,
A 130-kDa membrane protein of sperm flagella is the receptor for asterosaps, sperm-activating peptides of starfish Asterias amurensis.
2000,
Pubmed
,
Echinobase
Olson,
Allurin, a 21-kDa sperm chemoattractant from Xenopus egg jelly, is related to mammalian sperm-binding proteins.
2001,
Pubmed
Oren-Benaroya,
The sperm chemoattractant secreted from human cumulus cells is progesterone.
2008,
Pubmed
Pichlo,
High density and ligand affinity confer ultrasensitive signal detection by a guanylyl cyclase chemoreceptor.
2014,
Pubmed
,
Echinobase
Potter,
Dephosphorylation of the guanylyl cyclase-A receptor causes desensitization.
1992,
Pubmed
Potter,
Activation of protein kinase C stimulates the dephosphorylation of natriuretic peptide receptor-B at a single serine residue: a possible mechanism of heterologous desensitization.
2000,
Pubmed
Potter,
Guanylyl cyclase-linked natriuretic peptide receptors: structure and regulation.
2001,
Pubmed
Potthast,
Calcium-dependent dephosphorylation mediates the hyperosmotic and lysophosphatidic acid-dependent inhibition of natriuretic peptide receptor-B/guanylyl cyclase-B.
2004,
Pubmed
Ramírez-Gómez,
Sperm chemotaxis is driven by the slope of the chemoattractant concentration field.
2020,
Pubmed
,
Echinobase
Seifert,
The CatSper channel controls chemosensation in sea urchin sperm.
2015,
Pubmed
,
Echinobase
Shiba,
Ca2+ bursts occur around a local minimal concentration of attractant and trigger sperm chemotactic response.
2008,
Pubmed
Singh,
Membrane guanylate cyclase is a cell-surface receptor with homology to protein kinases.
1988,
Pubmed
,
Echinobase
Song,
Olfactory CNG channel desensitization by Ca2+/CaM via the B1b subunit affects response termination but not sensitivity to recurring stimulation.
2008,
Pubmed
Strünker,
At the physical limit - chemosensation in sperm.
2015,
Pubmed
,
Echinobase
Strünker,
The CatSper channel mediates progesterone-induced Ca2+ influx in human sperm.
2011,
Pubmed
Teves,
Progesterone at the picomolar range is a chemoattractant for mammalian spermatozoa.
2006,
Pubmed
Tomlin,
Biology by numbers: mathematical modelling in developmental biology.
2007,
Pubmed
Trötschel,
Absolute proteomic quantification reveals design principles of sperm flagellar chemosensation.
2020,
Pubmed
,
Echinobase
Ward,
Chemotaxis of Arbacia punctulata spermatozoa to resact, a peptide from the egg jelly layer.
1985,
Pubmed
,
Echinobase
Ward,
Dephosphorylation of sea urchin sperm guanylate cyclase during fertilization.
1986,
Pubmed
,
Echinobase
Yoshida,
A chemoattractant for ascidian spermatozoa is a sulfated steroid.
2002,
Pubmed
Yoshida,
Sperm chemotaxis and regulation of flagellar movement by Ca2+.
2011,
Pubmed