Fig. 2

Mutations in the rpl23a gene result in compromised expansion of ptf1a-expressing pancreatic progenitor cells. (A) Expression of rpl23a during zebrafish development is broad at 24 hpf and becomes increasingly restricted to the larval endoderm during the course of development. (B) Strong expression of rpL23a is observed in adult liver, intestine, and pancreas. (C) An incross of rpl23a^{hi2582/ +} ;ptf1a:eGFP^jh1;ins:mCherry ^jh2 adult fish results in 72 hpf embryos exhibiting reduced brain and eye size (red arrowhead), edema, and poor yolk absorption (blue arrowhead). (D) Fraction of embryos from rpl23a^{hi2582/ +} ;ptf1a:eGFP^jh1;ins:mCherry^jh2 incross displaying gross developmental defects as assessed at 72 hpf (29% mutant, red; 71%, wild type, blue) compared with control embryos generated by rpl23a^{hi2582/ +} ;ptf1a:eGFP^jh1;ins:mCherry^jh2 outcross (2.8% mutant, red; 97.2% wild type, blue). (E) ptf1a-expressing pancreatic progenitor cells fail to expand normally in embryos generated by rpl23a^{hi2582/ +} ;ptf1a:eGFP^jh1;ins:mCherry^jh2 incross. (F) Activation of trypsin expression occurs normally in rpl23a^{hi2582/hi2582} hypoplastic pancreas. Images in (E) and (F) obtained at 72 hpf. (G) PCR genotyping of embryos individually imaged at 72 hpf confirms reduced pancreatic mass in both heterozygous rpl23ahi2582/ + ;ptf1a:eGFPjh1; ins:mCherryjh2 and homozygous rpk23a^{hi2582/hi2582};ptf1a:eGFP^jh1; ins:mCherry^jh2 embryos. ^(H) Incidence of abnormal pancreas development in embryos produced by either incross or outcross rpl23a^{hi2582/ +} ;ptf1a:eGFPjh1; ins:mCherry^jh2 adults, expressed as the fraction of phenotypic (red) and wild-type (blue) embryos evaluated at 72 hpf. (I) Decreased incidence of persistent hypoplastic pancreas at 96 hpf indicates recovery of normal pancreatic mass in rpl23ahi2582/ + heterozygotes. Color images available online at www.liebertpub.com/zeb