Fig. 5

Figure 5. Triple Loss of Ythdf Readers Disrupts Zebrafish Development (A) MZythdf2;MZythdf3, background-matched wild-type, and unrelated TU-AB wild-type zebrafish embryos develop at similar rates. Parents of mutant and background-matched control embryos were 17α-ethynylestradiol treated. n, replicate number of embryos at same developmental stage. Scale bars, 500 μm. (B) Biplot of expression (log2 RPKM) of maternal (n = 13,642) and m⁶A-modified (n = 2,280) mRNAs between wild-type and MZythdf2;MZythdf3, from 6 hpf poly(A) mRNA-seq. Dashed lines, 2-fold change. (C) Cumulative distribution of fold changes in maternal mRNA abundance (log₂ RPKM) between 4 and 0 hpf in MZythdf2;MZythdf3 embryos, for m⁶A-modified (n = 708) and non-modified (n = 841) mRNAs, from poly(A) mRNA-seq. p values computed by a Mann-Whitney U test. (D) Schematic of cross and genotyping strategy for triple Ythdf mutants. Female fish (ythdf1+/−;ythdf2−/−;ythdf3+/−) were crossed to males (ythdf1−/−;ythdf-+/−;ythdf3−/−) to generate triple homozygotes (1 of 8 possible genotypes). Every 3 days, 48 larvae were genotyped, with 200 more fish genotyped at 30 dpf. (E) Percentage of triple heterozygous (het) or triple homozygous (homo) fish during development. Dotted line, expected percentage (12.5%) of each genotype, from cross in (D). (F) Number of fish with each genotype from cross in (D) at 30 dpf. For each ythdf allele: filled circle, heterozygous; m, homozygous. Dotted line, expected fish number (25), equal for all genotypes.