Fig. 2.

Role of Aub and piRNAs in germ cell mRNA localization to the germ plasm. a Immunostaining with anti-Osk of osk-bcd3′UTR (ob) embryos in wild-type or aub mutant backgrounds. The DAPI staining background (blue) shows the bulk of the embryo. Scale bars: 30 μm. b In situ hybrydization of 0–2 h ob/ + embryos either in wild-type or aub mutant backgrounds, with nos, pgc and gcl RNA probes. c Quantification of Osk and mRNA localization shown in a, b, respectively. 0–30 min-embryos were also quantified for nos mRNA. d Schematic representation of nos mRNA and base-pairing with piRNAs. Thin boxes are 5′- and 3′-UTRs, lines are introns, and thick boxes are exons. Crosslink clusters from Aub-iCLIP are indicated in red. The sequence of the region with the strongest crosslink sites is shown. Base-pairing with representative piRNAs from roo and 412 TEs is shown; the deletions overlaping the piRNA target sites in the nos(ΔpirooΔpi412) transgene are boxed¹⁵. Aub-crosslinked nt are in red. e nos mRNA in situ hybrydization of 0–2 h-embryos from wild-type and nos(ΔpirooΔpi412); nos ^BN females. The nos ^BN mutant does not produce nos mRNA in the embryo. f Quantification of nos mRNA posterior localization as shown in e, for wild-type embryos, nos ^BN embryos bearing the wild-type genomic nos (gnosb) transgene, and nos ^BN embryos bearing the nos(ΔpirooΔpi412) transgene from two independent stocks. ns: non-significant, ***p < 0.001, using χ2 test