25 Probes were generated by polymerase chain reaction (PCR) amplification from complementary DNA (cDNA) generated from 5-dpf RNA with the primers listed in Supporting Table 1. The bip probe was generated by the creation of cDNA with the zbip-3a primer. Nucleotides 1235 to 2260 of BC063946.1 were amplified with primers bip-5b and bip-3b. The DNA damage-inducible transcript 3 (chop) probe was amplified with primers zchop-5c and zchop-3, which spanned nucleotides 248 to 976 of NM_001082825.1.

The dnajc3 probe was amplified with primers zdnajc3-5p and zdnajc3-3p, which spanned nucleotides 318 to 819 of NM_199610. Each fragment was cloned into PCR II (Invitrogen) PD0325901 nmr and was sequenced. The probes were created with a digoxigenin RNA labeling mix (Roche).

Whole-mount in situ hybridizations were performed as described.24 Larvae at 5 dpf were HM781-36B mouse homogenized in a lysis buffer [20 mM trishydroxymethylaminomethane (pH 7.5), 150 mM sodium chloride, 1% Nonidet P40, 2 mM ethylene diamine tetraacetic acid, 10% glycerol, and protease inhibitors]; to a final concentration of 2% sodium dodecyl sulfate and 5% 2-mercaptoethanol. Two embryos were loaded onto a 10% polyacrylamide gel, blotted onto nitrocellulose, and incubated with antibodies recognizing α-tubulin (1:2000; Sigma), Bip (1:3000; Sigma) or phosphorylated eukaryotic translation initiation factor 2 subunit 1α (p-Eif2s1; 1:1000; 9721, Cell Signaling) MCE followed

by anti-mouse horseradish peroxidase–conjugated secondary antibody (1:1500; Jackson ImmunoResearch). Blots were visualized by chemiluminescence with a Fujifilm LAS-3000. The band intensities were quantified with Quantity One software (Bio-Rad). RNA was isolated from 5-dpf whole larvae, dissected livers, and liverless carcasses with the Qiagen RNeasy kit. cDNA was synthesized with Superscript II reverse transcriptase (Invitrogen). PCR reactions were performed as described.25 Real-time quantitative polymerase chain reaction (qPCR) was performed in triplicate with Roche SYBR Green on the Roche LightCycler 480 system. The change in the cycle threshold (ΔCt) was calculated for each target gene using the formula (2) with ribosomal protein P0 (rpp0) as the reference. The primer specificity (Supporting Table 1) was determined with a melting curve assessment; some amplicons were sequenced. All genes are referred to according to the nomenclature rules for the species under discussion. When no species is specified, zebrafish nomenclature rules are followed. All experiments were repeated for at least three clutches. For data presented as percentages of control values, we calculated either the average or the median and the standard deviation. The statistical tests included unpaired and paired two-tailed Student t tests, one-sample t tests, analyses of variance (ANOVAs), Fisher’s exact test, and chi-square analyses as appropriate.