Background expression levels of mitoferrin and transferrin in hypomorph mutants. Mitoferrin (A) and transferrin (B) expression in dmfrnBG00456 and tsf1f05108, respectively, was found to be lower than a standard laboratory strain, w1118 (***P<0.0001). Data are presented as means ± SEM and analyzed by student’s t-test. Sample sizes were as follows: for dmfrn expression, w1118 n=40, dmfrnBG00456 n=60 and for tsf expression, w1118 n=50, tsf1f05108 n=60.