Description

C. elegans contain three Δ9 fatty acid desaturases (FADs), fat-5, fat-6, and fat-7, responsible for the initial desaturation step in the synthesis of complex polyunsaturated fatty acids (PUFAs).  Production of PUFAs is vital for survival, as simultaneous loss-of-function in all three genes results in synthetic lethality (Brock et al. 2006).  Animals containing mutations in any one of the three Δ9 FADs, fat-5, fat-6, and fat-7, display an increase in body length. fat-5 mutants display a significant increase from 48 hours onward, while fat-6 and fat-7 display a significant increase from 72 hours onward. Since fat-6 and fat-7 mutants have reduced lipid accumulation (Horikawa et al. 2008; Zhang et al. 2013; Clark et al. 2018), these findings on body size suggest that the two phenotypes are not correlated. Consistent with this conclusion, dbl-1 mutants display both decreased body size and lipid accumulation while lon-2 and dbl-1(OE) mutants display increased body size and decreased lipid accumulation at the L4 stage (Clark et al. 2018). Error bars denote SEM, Statistical significance determined via Student’s T-test, n.s. not significant, * p<0.05, ** p<.0.01,*** p<0.001. n>25 per strain, repeated in duplicate.  Animals were synchronized via an egg lay followed by a timed hatch. Animals were collected and imaged at 25X using a QImaging Retiga EXi camera with QCapture software at each timepoint.  Body length was measured by tracing the midline of the animals in ImageJ.