Fig. 1.

Sperm from Atp1a4 knockout mice exhibit a bent in the flagellum. Bright field microscopy of sperm from wild type (WT) and Atp1a4 knockout (Atp1a4 KO) mice, obtained from a the cauda epididymis, b the testis, and c the caput caput of the epididymis. Sperm was collected in modified Whitten’s medium, placed on coverslips and images were obtained under a regular light microscope. The arrows show the different degree of angulation of the flagellum in sperm taken from the cauda epididymis. d Quantification of sperm flagellar bending. Sperm from the cauda epididymis of WT and Atp1a4 KO mice was collected in modified Whitten’s medium, placed on coverslips and sperm with angulated flagella were counted. All type of angulation, including retroflexed flagella, were considered as bent flagella. Results are expressed as a percent of the total number of cells. Values are the mean + SEM of 3 different experiments. Asterisks indicate statistical differences with respect WT controls and # shows differences with normal straight sperm flagella, with P < 0.05