Fig. 2

Figure 2. Ythdf2 Is Not Mandatory for Global Maternal Clearance but Marginally Contributes to m⁶A-Mediated Decay (A and B) Biplots of expression (log2 RPKM) of maternal (n = 13,642) and m⁶A-modified mRNAs (n = 2,280) between wild-type and MZythdf2 at 4 (A) or 6 (B) hpf, from poly(A) mRNA-seq. Dashed lines, 2-fold change. (C and D) Cumulative distributions of fold changes in maternal mRNA abundance (log2 RPKM) between MZythdf2 and wild-type at either 4 (C) or 6 (D) hpf, for m⁶A-modified (n = 708) and non-modified mRNAs (n = 841), from poly(A) mRNA-seq. p values computed by a Mann-Whitney U test. (E) In situs of methylated maternal mRNAs mtus1a and zgc:162879 in wild-type, MZythdf2, and MZmir-430 embryos at 2, 4, or 6 hpf. qRT-PCR mRNA abundance fold change (log2, 6 versus 2 hpf, mean ± SD, n = 3 independent replicates) on right. p values computed by a two-sided Student’s t test. Scale bars, 100 μM. (F) Methylated maternal mRNA abundance fold changes from qRT-PCR at 4 hpf between MZythdf2 and wild-type (mean ± SD, n = 3 independent replicates). Only brca2 (p = 5.4e−03) and vps26a (p = 6.3e−03) were significantly stabilized. (G) Northern blot of m⁶A-modified (+m6A) versus unmodified (−m⁶A) reporter at various time points (hpf) in MZythdf2 embryos. Loading control (18S rRNA, ~1,900 nt) on bottom. Ratio of m⁶A to non-m6A reporter abundance (18S rRNA normalized, mean ± SD, n = 2 independent replicates) on right. A0, reporter injected without poly(A) tail. For (A) –(F), wild-type label represents background-matched wild-type controls.