Genotype to phenotype: Diet-by-mitochondrial DNA haplotype interactions drive metabolic flexibility and organismal fitness
Basal ROS, antioxidant expression, mtDNA copy number and ATP levels Alstonville larvae had an advantage when fed the 1:2 P:C diet as the V161L ND4 amino acid change in complex I of Dahomey reduced the efficiency of ATP production.
(A) Measurement of basal ROS shows higher levels in Dahomey fed the 1:2 P:C diet. ROS levels were similar when larvae were fed the 1:16 P:C diet (n = 9 biological rep/mitotype on the 1:2 P:C diet, and 8 biological rep/mitotype on the 1:16 P:C diet with 2 failed reactions in Alstonville). (B). GstE1 and GstE5 expression was highest in Dahomey larvae fed the 1:2 P:C diet (n = 6 biological rep/mitotype/diet for both genes). (C) Alstonville larvae had higher mtDNA copy number when fed the 1:2 P:C diet but both mitotypes had equivalent and lower copy number when fed the 1:16 P:C diet. MtDNA copy number show the relative expression of ND4 (ND4/Actin) and lrRNA (lrRNA/Rp49) (n = 8 biological rep/mitotype/diet with 2 failed reactions for ND4/Actin and 7 biological reps/mitotype/diet for lrRNA/Rp49 with 2 failed reactions). (D) Total cellular ATP levels were higher in Alstonville larvae fed the 1:2 P:C diet but were similar when fed the 1:16 P:C diet suggesting a mitohormetic response (n = 8 biological rep/mitotype/diet, with two failed reactions) Bars show mean± s.e.m. t-tests between mitotypes * p< 0.05, ** p< 0.01 (see text).