N 0 hpf and 24 hpf. All classical dynamins appear to be deposited as maternal mRNAs and expressed throughout early development. doi:10.1371/journal.pone.0055888.gindicating that both dnm2 and dnm2-like are likely maternally deposited mRNAs (Figure 2D). Ubiquitous dnm2 HDAC-IN-3 expression was additionally confirmed by in situ hybridization in 1 dpf embryos (Figure S1).Morpholino-mediated Knockdown of Zebrafish dnm2 and dnm2-like Gene ExpressionTo better clarify the roles of dnm2 and dnm2-like, we used targeted morpholino oligonucleotides to knockdown expression ofboth genes during early development. Morpholinos were targeted to splice junctions in dnm2 and dnm2-like pre-mRNAs (Figure 3A), and the resulting products were confirmed to be out of frame by sequencing the RT-PCR products (Figure 3B). A standard control morpholino was injected for comparison (Gene-Tools). Both dnm2 MO (0.3 mM) and dnm2-like MO (0.1 mM) injection resulted in pronounced but non-overlapping developmental phenotypes compared to ctl MO (0.3 mM) injection (Figure 3C). Knockdown of Dnm2 caused a shorted body axis, small eyes, yolk and cardiac edema, shortened somites, and an upward tailDynamin-2 and Zebrafish DevelopmentFigure 3. Morpholino-mediated knockdown of dnm2 and dnm2-like expression results in morphological changes. (A) Splice targeting morpholinos were 
designed against intron-exon boundaries within the dnm2 and dnm2-like genes. (B) Knockdown in morpholino injected embryos was verified using RT-PCR. Embryos were injected with a 1662274 scrambled control morpholino (Ctl MO; 0.3 mM), dnm2 MO (0.3 mM), or dnm2-like MO (0.1 mM). Arrows indicate the alternative splice product induced by dnm2 MO and dnm2-like MO injection. dnm2 MO injection also resulted in an additional higher weight band due to Dimethylenastron activation of a cryptic splice site (*). (C) At 2 dpf, dnm2 MO-injected embryos exhibit shortened body length, upward curled tails, pericardial and yolk edema, and reduced head size when compared to control morpholino injected embryos. By contrast, embryos injected with dnm2-like MO have small muscle compartments, pigmentation defects, and mild tail curvature. (D) Percent of affected embryos at 2 dpf (ctl MO vs. dnm2 MO p,0.0001, ctl MO vs. dnm2-like MO p,0.0001; Fisher’s exact test). The total number of embryos is noted above each bar. doi:10.1371/journal.pone.0055888.gcurvature. Knockdown of Dnm2-like resulted in a thinned body axis, small eyes, and pigmentation defects. The 1516647 severity and penetrance of morpholino phenotypes was consistent between injections (control n = 601, dnm2 n = 601, dnm2-like n = 587). At 2 dpf, both morpholino groups had a significant increase in abnormal morphology relative to control morpholino (Figure 3D;p,0.0001, Fisher’s exact test); 93 of dnm2 morphants and 74 of dnm2-like morphants exhibited the described phenotypes, while only 4 of control embryos displayed any developmental abnormalities. To determine knockdown of dynamin-2 expression in dnm2 and dnm2-like morphants, isolated muscle fibers were stained with an antibody against dynamin-2. Cells from both dnmDynamin-2 and Zebrafish DevelopmentDynamin-2 and Zebrafish DevelopmentFigure 4. Knockdown of dnm2 results in motor deficits and abnormal muscle histology. (A) Quantitation of spontaneous embryo coiling at 1 dpf. On average, control morphants coiled 35.7 times in 60 seconds, while dnm2 morphants coiled only 9.5 times. (B-C) Touch-evoked swimming was measured in 3 dpf morphants. Most control and dnm2-li.N 0 hpf and 24 hpf. All classical dynamins appear to be deposited as maternal mRNAs and expressed throughout early development. doi:10.1371/journal.pone.0055888.gindicating that both dnm2 and dnm2-like are likely maternally deposited mRNAs (Figure 2D). Ubiquitous dnm2 expression was additionally confirmed by in situ hybridization in 1 dpf embryos (Figure S1).Morpholino-mediated Knockdown of Zebrafish dnm2 and dnm2-like Gene ExpressionTo better clarify the roles of dnm2 and dnm2-like, we used targeted morpholino oligonucleotides to knockdown expression ofboth genes during early development. Morpholinos were targeted to splice junctions in dnm2 
and dnm2-like pre-mRNAs (Figure 3A), and the resulting products were confirmed to be out of frame by sequencing the RT-PCR products (Figure 3B). A standard control morpholino was injected for comparison (Gene-Tools). Both dnm2 MO (0.3 mM) and dnm2-like MO (0.1 mM) injection resulted in pronounced but non-overlapping developmental phenotypes compared to ctl MO (0.3 mM) injection (Figure 3C). Knockdown of Dnm2 caused a shorted body axis, small eyes, yolk and cardiac edema, shortened somites, and an upward tailDynamin-2 and Zebrafish DevelopmentFigure 3. Morpholino-mediated knockdown of dnm2 and dnm2-like expression results in morphological changes. (A) Splice targeting morpholinos were designed against intron-exon boundaries within the dnm2 and dnm2-like genes. (B) Knockdown in morpholino injected embryos was verified using RT-PCR. Embryos were injected with a 1662274 scrambled control morpholino (Ctl MO; 0.3 mM), dnm2 MO (0.3 mM), or dnm2-like MO (0.1 mM). Arrows indicate the alternative splice product induced by dnm2 MO and dnm2-like MO injection. dnm2 MO injection also resulted in an additional higher weight band due to activation of a cryptic splice site (*). (C) At 2 dpf, dnm2 MO-injected embryos exhibit shortened body length, upward curled tails, pericardial and yolk edema, and reduced head size when compared to control morpholino injected embryos. By contrast, embryos injected with dnm2-like MO have small muscle compartments, pigmentation defects, and mild tail curvature. (D) Percent of affected embryos at 2 dpf (ctl MO vs. dnm2 MO p,0.0001, ctl MO vs. dnm2-like MO p,0.0001; Fisher’s exact test). The total number of embryos is noted above each bar. doi:10.1371/journal.pone.0055888.gcurvature. Knockdown of Dnm2-like resulted in a thinned body axis, small eyes, and pigmentation defects. The 1516647 severity and penetrance of morpholino phenotypes was consistent between injections (control n = 601, dnm2 n = 601, dnm2-like n = 587). At 2 dpf, both morpholino groups had a significant increase in abnormal morphology relative to control morpholino (Figure 3D;p,0.0001, Fisher’s exact test); 93 of dnm2 morphants and 74 of dnm2-like morphants exhibited the described phenotypes, while only 4 of control embryos displayed any developmental abnormalities. To determine knockdown of dynamin-2 expression in dnm2 and dnm2-like morphants, isolated muscle fibers were stained with an antibody against dynamin-2. Cells from both dnmDynamin-2 and Zebrafish DevelopmentDynamin-2 and Zebrafish DevelopmentFigure 4. Knockdown of dnm2 results in motor deficits and abnormal muscle histology. (A) Quantitation of spontaneous embryo coiling at 1 dpf. On average, control morphants coiled 35.7 times in 60 seconds, while dnm2 morphants coiled only 9.5 times. (B-C) Touch-evoked swimming was measured in 3 dpf morphants. Most control and dnm2-li.
