Identification of a long noncoding RNA required for temperature induced expression of stage-specific rRNA in malaria parasites.

Protozoan parasites of the genus Plasmodium cause malaria, a mosquito borne disease responsible for substantial health and economic costs throughout the developing world. During transition from human host to insect vector, the parasites undergo profound changes in morphology, host cell tropism and gene expression. Unique among eukaryotes, Plasmodium differentiation through each stage of development includes differential expression of singular, stage-specific ribosomal RNAs, permitting real-time adaptability to major environmental changes. In the mosquito vector, these Plasmodium parasites respond to changes in temperature by modulating transcriptional activities, allowing real-time responses to environmental cues. Here, we identify a novel form of long noncoding RNA: a temperature-regulated untranslated lncRNA (tru-lncRNA) that influences the Plasmodium parasite's ability to respond to changes in its local environment. Expression of this tru-lncRNA is specifically induced by shifts in temperature from 37 °C to ambient temperature that parallels the transition from mammalian host to insect vector. Interestingly, deletion of tru-lncRNA from the genome may prevent processing of S-type rRNA thereby affecting the protein synthesis machinery. Malaria prevention and mitigation strategies aimed at disrupting the Plasmodium life cycle will benefit from the characterization of ancillary biomolecules (including tru-lncRNAs) that are constitutively sensitive to micro- environmental parameters.