Fig. 5.

Paf1 is necessary for maintenance of blood and germline stem cell populations. (A-D) Expression of myb (A,B) or tal1 (C,D), markers of early blood precursors in the anterior and posterior lateral mesoderm at 12 hpf, is similar in aln^z24 mutant and wild-type sibling embryos. (E-H) In contrast, by 26 hpf, expression of myb (E,F) and tal1 (G,H) in the intermediate cell mass is significantly reduced in aln^z24 mutant embryos. (I-N) Wild-type sibling and aln^z24; askopos::GFP transgenic embryos that express GFP in PGCs. Small clusters of PGCs arise similarly in wild-type and aln^z24 mutant 50-60% epiboly embryos (I,J). PGCs are present in two bilateral clusters at 12 hpf (K) and coalesce at the midline above the yolk extension in 32 hpf (M) wild-type sibling embryos. In contrast, PGCs are present in ectopic locations in 12 hpf (L) and 32 hpf (N) aln^z24 mutant embryos. Brackets and arrows indicate normal clusters of PGCs, whereas arrowheads indicate ectopic PGCs. y, yolk; ye, yolk extension. A-D,K,L are dorsal views with anterior towards the left; E-H,M,N, are lateral views with anterior towards the left; I,J are dorsolateral views with animal pole upwards.