Fig. 6. MO-mediated knock-down of matriptase 1 rescues hi2217 mutant. (A) In situ hybridization of zebrafish matriptase 1 in wild-type embryo at 30 hpf; inset shows an embryo labeled with a sense probe from the same plasmid template. (B-G) Live images of hi2217 embryos injected with either matriptase 1 MO1 (B,C,D,F) a standard control MO (E) or a 5-base mismatch matriptase 1 MO1 (G) at 30 hpf (B-E) or 48 hpf (F,G). (H) Quantification of morphological data at 30 and 48 hpf; the number of embryos exhibiting a mutant (mut) morphology (as in D,E,G) were counted for each condition and divided by the total number of embryos to give the percentage that exhibit the mutant phenotype (%). Note that any instance of rounded cells (e.g. that seen in D, even with an otherwise wild-type morphology) was counted as a mutant phenotype. (I,J) MPO activity assay of embryos fixed at 48 hpf following injection with matriptase 1 MO1 (I) or 5-base mismatch matriptase 1 MO1 (J). (K,L) Partial phenocopy by injection of a lesser volume of matriptase 1 MO. OCC (K) and corresponding MPO immunolabeling (L) of an hi2217 embryo injected with matriptase 1 MO2 at a concentration less than required for rescue (see Materials and Methods), note the recruitment of neutrophils to localized areas of rounded cells (arrows in K). Note that the similar injection of 5-base mismatch matriptase 1 MO1 into other embryos resulted in 25% showing a `full' mutant phenotype similar to that seen in G and J (data not shown). Embryos are oriented anterior to the left, dorsal side up (A-C,F-L) or anterior up, dorsal side to the right (D,E). Bars, 100 µm.