Fig. 5

Knockdown of rpl3 phenocopies Sbds^ATG MO-induced defects in pancreas development. (A) Expression of rpl3 is widespread at 24 hpf and becomes progressively restricted to the endoderm, with high-level pancreatic expression at 120 hpf. The principal islet (I) is labeled by in situ hybridization for insulin (red). (B) rpl3 expression is decreased in Sbds^ATG MO-injected embryos, as quantified by microarray analysis of transcript abundance. Error bars indicate s.e.m. (C) In situ hybridization for rpl3 in Sbds^ATG MO-injected p53^zdf1/zdf1 embryos confirms loss of rpl3 expression in somites (black arrows), central nervous system (white arrows), pharyngeal arches (red arrows) and intestine (yellow arrows) of developing embryos. (D) An MO dose-dependent defect in pancreas progenitor expansion was observed in Rpl3^ATG MO-injected ptf1a:eGFP;ins:mCherry;p53^zdf1/zdf1 embryos. (E) The small pancreas (arrow) of p53^zdf1/zdf1 embryos injected with 0.5 ng Rpl3^ATG MO is positive for trypsin expression by in situ hybridization. (F) p53^zdf1/zdf1 embryos injected with 0.5 ng Rpl3^ATG MO at 72 hpf exhibit small heads and hydroencephaly (yellow arrowhead). (G) rpl3^hi2437/+;ptf1a:eGFP;ins:mCherry heterozygotes bearing a mutagenic rpl3 transgenic insertion were incrossed. rpl3^{hi2437/hi2437} homozygous embryos displayed disrupted pancreas progenitor expansion at 72 hpf. Injection of rpl3^hi2437;ptf1a:eGFP;ins:mCherry with the p53^ATG MO did not rescue the pancreatic progenitor phenotype of homozygous rpl3^{hi2437hi/2437} embryos. L, liver; P, pancreas; I, islet; Ex, exocrine pancreas.