Fig. 5

Loss of Kremen1 leads to non-cell-autonomous defects in the pLLP. (A-D) Live confocal projections of mosaic, Tg(cldnB:GFP) WT or krm1^nl10 embryos containing rhodamine-labeled donor cells (red) from WT donor embryos at 24 and 48hpf. At 24hpf, donor cells are found in the leading region of pLLP in WT (A) and mutant (C) hosts. At 48hpf, the pLLP shown in A has migrated along the length of the trunk and formed the terminal cluster (tc; B), whereas the mutant pLLP in C has failed to migrate and diminished to a thin trail of cells (D, yellow arrowhead). (E-H3) Live confocal projections of WT and krm1^nl10 host embryos that express TgBAC(neuroD:eGFP) and contain donor cells from Tg(7xtcf-siam:eGFP) donor embryos labeled with rhodamine (red). At 24hpf, the leading region of primordia of both WT (E-E3) and mutant (F-F3) hosts contain GFP-positive (E2,F2) and rhodamine-positive (E3,F3) donor cells (white arrows). At 48hpf, GFP/rhodamine-positive cells remain in the leading zone of WT primordia (G-H3, white arrows). In krm1^nl10 mutant primordia, few GFP-positive cells remain (H-H2), and the remaining rhodamine-positive donor cells are fragmented and appear to undergo cell death (H3 blue arrowheads). (I) Quantification of Tg(7xtcf-siam:eGFP)-positive donor cells at 24 hpf and 48 hpf in control (WT donor cells in WT hosts) and experimental (WT donor cells in krm1^nl10 hosts) primordia (n=5 krm1^nl10 hosts, 10 WT hosts; **P=0.007, Student′s t-test). Scale bars: 20μm.