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Behavioral mechanisms of mammalian sperm guidance.

Perez-Cerezales S, Boryshpolets S, Eisenbach M - Asian J. Androl. (2015 Jul-Aug)

Bottom Line: In mammals, sperm guidance in the oviduct appears essential for successful sperm arrival at the oocyte.Hitherto, three different potential sperm guidance mechanisms have been recognized: thermotaxis, rheotaxis, and chemotaxis, each of them using specific stimuli - a temperature gradient, fluid flow, and a chemoattractant gradient, respectively.Here, we review sperm behavioral in these mechanisms and indicate commonalities and differences between them.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Chemistry, The Weizmann Institute of Science, 7610001 Rehovot, Israel.

ABSTRACT
In mammals, sperm guidance in the oviduct appears essential for successful sperm arrival at the oocyte. Hitherto, three different potential sperm guidance mechanisms have been recognized: thermotaxis, rheotaxis, and chemotaxis, each of them using specific stimuli - a temperature gradient, fluid flow, and a chemoattractant gradient, respectively. Here, we review sperm behavioral in these mechanisms and indicate commonalities and differences between them.

No MeSH data available.


Behavioral response of human spermatozoa to temporal temperature changes. Spermatozoa were exposed to the indicated temperature changes and their motility and trajectories were recorded and analyzed. The figure shows the motility parameters curvilinear velocity (VCL), average pass velocity (VAP), straight-line velocity (VSL), linearity (LIN), wobble (WOB), percentage of hyperactivated spermatozoa and example of sperm trajectories. (a) Heating and cooling thermogram of the microscope's heating stage. (b) Temperature-jump stimulated changes in average velocity parameters. (c) Temperature-jump stimulated changes in the calculated values of linearity and wobble. (d) Representative sperm trajectories at 31°C just prior to temperature shift and at 37°C just after the temperature shift. Red arrows indicate hyperactivation events. (e) Temperature-jump stimulated changes in the percentage of hyperactivated spermatozoa (Taken with permission from Boryshpolets et al.28).
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Figure 2: Behavioral response of human spermatozoa to temporal temperature changes. Spermatozoa were exposed to the indicated temperature changes and their motility and trajectories were recorded and analyzed. The figure shows the motility parameters curvilinear velocity (VCL), average pass velocity (VAP), straight-line velocity (VSL), linearity (LIN), wobble (WOB), percentage of hyperactivated spermatozoa and example of sperm trajectories. (a) Heating and cooling thermogram of the microscope's heating stage. (b) Temperature-jump stimulated changes in average velocity parameters. (c) Temperature-jump stimulated changes in the calculated values of linearity and wobble. (d) Representative sperm trajectories at 31°C just prior to temperature shift and at 37°C just after the temperature shift. Red arrows indicate hyperactivation events. (e) Temperature-jump stimulated changes in the percentage of hyperactivated spermatozoa (Taken with permission from Boryshpolets et al.28).

Mentions: The behavioral response of human spermatozoa to a spatial temperature gradient appears to be very similar to their response to a chemoattractant gradient, even though the responses to a temporal gradient are not identical. When spermatozoa are exposed to a fast temperature drop (i.e., to a negative temperature gradient; Figure 2a), their behavioral response consists of two components.28 One component is rather trivial – speed decrease expressed in all velocity parameters (Figure 2b). The other component is a drop in the linearity of swimming. This is reflected both in the motility parameters that represent the extent of the linearity of swimming (Figure 2c) and in the extent of side-to-side head displacement (i.e., hyperactivation; Figure 2d and 2e), resulting from higher amplitude of the flagellar wave propagation.28 The inverse response is seen when the temperature increases. It is probable that these observed changes reflect to a large extent the sperm response to the ambient temperature. However, they also reflect the response to the temperature gradient per se. This was deduced from the partial adaptation of the cells following their excitatory response (e.g., Figure 2e). In other words, spermatozoa can sense both the temperature gradient and the absolute ambient temperature. The reduced linearity and increase in hyperactivation events in response to a temperature drop led to the expansion of the model of human sperm behavior in a chemoattractant gradient (Figure 1b) to thermotaxis.28 Specifically, a capacitated spermatozoon that swims up a temperature gradient is continuously stimulated with a resultant increased velocity and linearity, due to a low level of head side-to-side displacement. When a spermatozoon swims down the gradient its velocity decreases and the frequency of turning and hyperactivation events increases until the cell happens to swim up the gradient. When a spermatozoon stops sensing the temperature gradient for a while it adapts, resuming its unstimulated swimming – a rather straight swimming with occasional turns and hyperactivation events.


Behavioral mechanisms of mammalian sperm guidance.

Perez-Cerezales S, Boryshpolets S, Eisenbach M - Asian J. Androl. (2015 Jul-Aug)

Behavioral response of human spermatozoa to temporal temperature changes. Spermatozoa were exposed to the indicated temperature changes and their motility and trajectories were recorded and analyzed. The figure shows the motility parameters curvilinear velocity (VCL), average pass velocity (VAP), straight-line velocity (VSL), linearity (LIN), wobble (WOB), percentage of hyperactivated spermatozoa and example of sperm trajectories. (a) Heating and cooling thermogram of the microscope's heating stage. (b) Temperature-jump stimulated changes in average velocity parameters. (c) Temperature-jump stimulated changes in the calculated values of linearity and wobble. (d) Representative sperm trajectories at 31°C just prior to temperature shift and at 37°C just after the temperature shift. Red arrows indicate hyperactivation events. (e) Temperature-jump stimulated changes in the percentage of hyperactivated spermatozoa (Taken with permission from Boryshpolets et al.28).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492055&req=5

Figure 2: Behavioral response of human spermatozoa to temporal temperature changes. Spermatozoa were exposed to the indicated temperature changes and their motility and trajectories were recorded and analyzed. The figure shows the motility parameters curvilinear velocity (VCL), average pass velocity (VAP), straight-line velocity (VSL), linearity (LIN), wobble (WOB), percentage of hyperactivated spermatozoa and example of sperm trajectories. (a) Heating and cooling thermogram of the microscope's heating stage. (b) Temperature-jump stimulated changes in average velocity parameters. (c) Temperature-jump stimulated changes in the calculated values of linearity and wobble. (d) Representative sperm trajectories at 31°C just prior to temperature shift and at 37°C just after the temperature shift. Red arrows indicate hyperactivation events. (e) Temperature-jump stimulated changes in the percentage of hyperactivated spermatozoa (Taken with permission from Boryshpolets et al.28).
Mentions: The behavioral response of human spermatozoa to a spatial temperature gradient appears to be very similar to their response to a chemoattractant gradient, even though the responses to a temporal gradient are not identical. When spermatozoa are exposed to a fast temperature drop (i.e., to a negative temperature gradient; Figure 2a), their behavioral response consists of two components.28 One component is rather trivial – speed decrease expressed in all velocity parameters (Figure 2b). The other component is a drop in the linearity of swimming. This is reflected both in the motility parameters that represent the extent of the linearity of swimming (Figure 2c) and in the extent of side-to-side head displacement (i.e., hyperactivation; Figure 2d and 2e), resulting from higher amplitude of the flagellar wave propagation.28 The inverse response is seen when the temperature increases. It is probable that these observed changes reflect to a large extent the sperm response to the ambient temperature. However, they also reflect the response to the temperature gradient per se. This was deduced from the partial adaptation of the cells following their excitatory response (e.g., Figure 2e). In other words, spermatozoa can sense both the temperature gradient and the absolute ambient temperature. The reduced linearity and increase in hyperactivation events in response to a temperature drop led to the expansion of the model of human sperm behavior in a chemoattractant gradient (Figure 1b) to thermotaxis.28 Specifically, a capacitated spermatozoon that swims up a temperature gradient is continuously stimulated with a resultant increased velocity and linearity, due to a low level of head side-to-side displacement. When a spermatozoon swims down the gradient its velocity decreases and the frequency of turning and hyperactivation events increases until the cell happens to swim up the gradient. When a spermatozoon stops sensing the temperature gradient for a while it adapts, resuming its unstimulated swimming – a rather straight swimming with occasional turns and hyperactivation events.

Bottom Line: In mammals, sperm guidance in the oviduct appears essential for successful sperm arrival at the oocyte.Hitherto, three different potential sperm guidance mechanisms have been recognized: thermotaxis, rheotaxis, and chemotaxis, each of them using specific stimuli - a temperature gradient, fluid flow, and a chemoattractant gradient, respectively.Here, we review sperm behavioral in these mechanisms and indicate commonalities and differences between them.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Chemistry, The Weizmann Institute of Science, 7610001 Rehovot, Israel.

ABSTRACT
In mammals, sperm guidance in the oviduct appears essential for successful sperm arrival at the oocyte. Hitherto, three different potential sperm guidance mechanisms have been recognized: thermotaxis, rheotaxis, and chemotaxis, each of them using specific stimuli - a temperature gradient, fluid flow, and a chemoattractant gradient, respectively. Here, we review sperm behavioral in these mechanisms and indicate commonalities and differences between them.

No MeSH data available.