The <i>N</i>. <i>crassa hac-1</i> mRNA is processed under ER stress.

<p>A) (Top) Schematic representation of the position of the primers used to detect the processing of the unconventional intron in the <i>N</i>. <i>crassa hac-1</i> mRNA. The position of the intron is shown as a triangle. (Bottom) RT-PCR analysis from WT strain (FGSC #988) to detect processing of the <i>N</i>. <i>crassa hac-1</i> mRNA upon chemically-induced ER stress. Amplification using the same primers, but with genomic DNA (gDNA) as template, is shown for size comparison. B) RT-PCR analysis to detect expression of homologs of typical UPR target genes, <i>grp78</i>/<i>bip</i> (<i>NCU03982</i>) and <i>pdi</i> (<i>NCU09223</i>), under ER stress in both WT and Δ<i>hac-1</i> strains. Amplification with primers for <i>actin</i> mRNA was used as a loading control. C) Real-time quantitative PCR analysis of the expression levels of the distinct isoforms of <i>hac-1</i> mRNA (t: total; u: uninduced; i: induced) under ER stress with DTT for the times depicted. Bars represent mean expression values +/- 95% confidence intervals, from 3 independent biological replicates. D) RT-PCR analysis for detecting changes in the length of the 5’ UTR of the <i>N</i>. <i>crassa hac-1</i> transcript upon ER stress. Primers targeting a 5’ UTR region close to the start codon (5’ UTR proximal) and a region further upstream (5’ UTR distal) were used. Assays were performed on 3 biological replicates per condition with similar results.