Nonsense-mediated decay machinery in is inefficient and non-essential.

Nonsense-mediated decay (NMD) is a conserved mRNA quality control process that eliminates transcripts bearing a premature termination codon. In addition to its role in removing erroneous transcripts, NMD is involved in post-transcriptional regulation of gene expression via programmed intron retention in metazoans. The apicomplexan parasite shows relatively high levels of intron retention, but it is unclear whether these variant transcripts are functional targets of NMD.