Conserved Genes Act as Modifiers of Invertebrate SMN Loss of Function Defects (original) (raw)
Figure 5
Loss of PLS3 orthologs enhances SMN loss of function defects in invertebrates.
Previous studies in vertebrates suggested that PLS3 orthologs in C. elegans and Drosophila might modify SMN loss of function defects [37]. A) A genetic interaction was found between the Drosophila PLS3 ortholog (Fimbrin or Fim) and _Dm_Smn using previously described _Dm_Smn RNAi knockdown lines [26] and Fim loss of function alleles. Percentage early or late larval lethality is reported. Ubiquitous RNAi knockdown of _Dm_Smn using the tubulinGAL4 (TubGAL4) driver results in pupal death; modifier genes alter the percentage of animals that die at early versus late pupal stages (day 7 versus day 9 [26]). Loss of Fim function significantly increased the percentage of animals that died as early pupae (p≤0.05 by Chi-square analysis); Fim is an enhancer of _Dm_Smn loss of function growth/survival defects. At least 100 animals of each genotype were scored in four replicates for the lethality assay. No significant variation was observed between control and experimental crosses with each independent trial. B) The Drosophila d02114 allele likely eliminates Fim function and in homozygous animals modestly perturbs NMJ morphology at larval muscle 4. Fimd02114 enhances _Dm_Smn loss of function NMJ defects consistent with studies in vertebrates [37]. All strains carry the ubiquitous TubGAL4 driver. Significance of p≤0.05 versus single mutant strains was determined by ANOVA and is indicated with asterisk; S.E.M. is shown. In representative images, red corresponds to anti-Discs Large (DLG), green is anti-synaptotagmin and blue is DAPI; scale bar indicates 15 microns.