Figure 1.

Sperm movement patterns during re-orientation to the progesterone source. (a) Qualitative description of the movement patterns that were observed in the sperm population that returned to the well in the absence or presence of progesterone (P); black track: linear; red track: transitional; green track: hyperactivated; yellow track: sperm stop. (b, c) The percentage of spermatozoa that show each of the six patterns of movement described in (a) in two different experimental settings: progesterone was placed in either W1 (b, inset) or W2 (c, inset), wherein the direction of the progesterone gradient is shown in light blue between both wells, and the returning sperm population in red. ^aP<0.05, compared with negative control, chemotaxis inhibitor and non-capacitated spermatozoa. Data are expressed as the mean±s.e.