Fig. 6.

Spermatozoa from Na,K-ATPase α4-null mice display abnormal morphology and show altered [Na⁺]_i and membrane potential. (A) Sperm morphology. Sperm was plated onto glass coverslips, fixed using buffered formalin phosphate, and stained with Trypan Blue. Images were taken under bright field using a 60× objective in a Nikon Eclipse 80i scope (Nikon Instruments, Inc.). (Scale bar, 100 μm.) (B) [Na⁺]_i determinations in sperm using the fluorescent indicator Sodium Green Tetraacetate. (C) Sperm membrane-potential determinations using [DiSC₃(5)]. Bars represent the mean ± SEM of three experiments. Values significantly different from the wild-type: *P < 0.001.