Increasing levels of salvage pathway enzymes, sugars, or Dpagt1 inhibits eye formation in zebrafish. (A) (Left) Injection of DNagk or Nagk mRNAs inhibits eye formation in zebrafish. (Right) Representative images (5 days post fertilization) of disrupted eye formation in zebrafish injected with Nagk mRNA. Observed phenotypes ranged from reduced eye size to missing one or both eyes. Reduced eyes were defined as less than half the size of a wild-type eye. (B) Injection of mRNAs encoding Nagk, Pgm3, Uap1, or Dpagt1 inhibits eye formation. (C) Injection of GlcNAc, GlcNAc-6-P, GlcNAc-1-P, or UDP-GlcNAc inhibits eye formation. Results are aggregates of n ≥ 3 replicates. Injections were performed with 0.5 ng mRNA or 25 pmol sugar. Significance was calculated using Fisher's exact test with Bonferroni correction. Absolute numbers are indicated above bars. (A) *ρ < 0.0253 and **ρ < 0.00501. (B–C) *ρ < 0.0127, **ρ < 0.00251, and *** ρ < 0.000251.