Xenbase Image ID: 139698

Fig. 10. ErbB signaling influenced formation of membrane protrusions. Embryos were injected with membrane-tethered EGFP with or without ErbB4-MO and human ErbB4. DMZ explants were dissected and dissociated in CMFB for an hour, and dissociated cells were plated on FN-coated coverslip in MBSH for an hour to allow cell adhesion. Time-lapse movies were made to record the membrane protrusive activities. (A) Control cells showed dynamic lamellipodia and filopodia formation, whereas cells expressing ErbB4-MO did not form these protrusions efficiently. Instead, they had dynamic membrane blebs. The defects in protrusive activities were rescued when ErbB4-MO was coexpressed with human ErbB4 RNA. (B) Quantification of membrane protrusions in different samples. Lamellipodia, filopodia and membrane blebs were counted separately and summarized in the bar graph. An average of 1.3 lamellipodia, 1.7 filopodia and 0.3 membrane blebs per minute were observed in control cells. Expression of ErbB4-MO decreased both lamellipodia and filopodia to 0.3 times per minute, but increased membrane blebs to 0.7 times per minute. Coinjection of human ErbB4 shifted the frequencies of these membrane protrusions back to 0.9, 1.3 and 0.3 times per minute respectively. Student t-test indicated that the differences in protrusive activities between ErbB-MO and control cells were significant (p-values of 2.4E-24, 1.3E-9 and 1.7E-2 for the three different protrusions), while the differences between control and the rescued samples were not significant (p-values of 0.08, 0.19 and 0.35 for the three protrusions). The total numbers of cells counted were given under the bar graph. Image published in: Nie S and Chang C (2007) Copyright © 2007. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View

Return to previous page