Figure 1. Protein level and activity of PLD1 during the development of hippocampal neurons. A, Western blot analysis of PLD1 in developing hippocampal neurons at indicated time points. B, Quantification of PLD1 protein levels during the development of hippocampal neurons. n = 7 samples each time point. *p < 0.05, between DIV 3 and DIV 1. ##p < 0.01, between DIV 7 and DIV 3, DIV 9 and DIV3, DIV11 and DIV3, and one-way ANOVA followed by Newman–Keuls multiple-comparison test. C, Quantification of PLD activity in developing hippocampal neurons. n = 3 samples each time point. *p < 0.05, between DIV 3 and DIV 1. #p < 0.05, between DIV 7 and DIV 3. ##p < 0.01, between DIV 9 and DIV3, DIV 11 and DIV 3, and one-way ANOVA followed by Newman–Keuls multiple-comparison test. D, The correlation between PLD1 protein levels and PLD activities (r2 = 0.8261, p < 0.05). E, Quantification of primary dendrites, secondary dendrites, and dendritic tips from DIV 3 to DIV 11. DIV 3, n = 22; DIV 5, n = 25; DIV 7, n = 24; DIV 9, n = 25; DIV 11, n = 18. *p < 0.05, between DIV 9, 11 and DIV 3. #p < 0.05, between DIV 9, 11 and DIV 5 in primary dendrites. ***p < 0.001, between DIV 7, 9, 11 and DIV 3. #p < 0.05, between DIV 11 and DIV 5 in secondary dendrites. ***p < 0.001, between DIV 7, 9, 11 and DIV 3. ###p < 0.001, between DIV 7, 9, 11 and DIV 5 in dendritic tips, one-way ANOVA followed by Newman–Keuls multiple-comparison test. F–H, The correlation between the number of dendrites or dendritic tips and PLD1 protein levels or PLD activities from DIV 3 to DIV 11. F, Primary dendrites: PLD1 protein level: r2 = 0.6220, p = 0.1129; PLD activity: r2 = 0.7752, p < 0.05. G, Secondary dendrites: PLD1 protein level: r2 = 0.7631, p = 0.0529; PLD activity: r2 = 0.8098, p < 0.05. H, Dendritic tips: PLD1 protein level: r2 = 0.8638, p < 0.05; PLD activity: r2 = 0.7868, p < 0.05.