Fig. 9.
Membrane insertion and lateral diffusion of exogenous BODIPY-GM1 in live sperm. (A) Fluorescence localization of BODIPY-GM1 in the sperm plasma membrane. BODIPY-GM1 inserted throughout the sperm plasma membrane showing a diffuse labeling pattern across the APM, PAPM and flagellum alike in live cells. (B) FLIP on the APM domain in BODIPY-GM1 labeled live sperm. Multiple cells were examined in 3 independent experiments and representative data are shown. (I) Shows a BODIPY-GM1 labeled live sperm; the white circle on the APM indicates the region of bleach in this experiment and the white arrow over the PAPM shows the location and direction used for generating the line intensity profile. (II) Panels 1 and 2 represent frames captured before and after the bleach of the same sperm. (III) Line intensity traces from frames 1 and 2 show loss of fluorescence intensity over the entire sperm head including the PAPM. (C) FLIP on the PAPM in BODIPY-GM1 labeled live sperm. Multiple cells were examined in 3 independent experiments and representative data are shown. (I) Shows a BODIPY-GM1 labeled live sperm; the white circle on the PAPM indicates the region of bleach in this experiment and the white arrow over the APM shows the location and direction used for generating the line intensity profile. (II) Panels 1 and 2 represent frames captured before and after the bleach of the same sperm. (III) Line intensity traces from frames 1 and 2 show loss of fluorescence intensity over the entire sperm head including the APM. Taken together, data from (B) and (C) show that exogenous BODIPY-GM1 molecules were capable of diffusion across the SAR in both directions.