Analysis by RNA-seq of transcriptomic changes elicited by heat shock in Leishmania major

Abstract

Besides their medical relevance, Leishmania is an adequate model for studying post-transcriptional mechanisms of gene expression. In this microorganism, mRNA degradation/stabilization mechanisms together with translational control and post-translational modifications of proteins are the major drivers of gene expression. Leishmania parasites develop as promastigotes in sandflies and as amastigotes in mammalians, and during host transmission, the parasite experiences a sudden temperature increase. Here, changes in the transcriptome of Leishmania major promastigotes after a moderate heat shock were analysed by RNA-seq. Several of the up-regulated transcripts code for heat shock proteins, other for proteins previously reported to be amastigote-specific and many for hypothetical proteins. Many of the transcripts experiencing a decrease in their steady-state levels code for transporters, proteins involved in RNA metabolism or translational factors. In addition, putative long noncoding RNAs were identified among the differentially expressed transcripts. Finally, temperature-dependent changes in the selection of the spliced leader addition sites were inferred from the RNA-seq data, and particular cases were further validated by RT-PCR and Northern blotting. This study provides new insights into the post-transcriptional mechanisms by which Leishmania modulate gene expression.

Minor temperature shifts do not affect chromosomal ploidy but cause transcriptomic changes in Leishmania braziliensis promastigotes in vitro

“…(27) As reported in the current study, other genes that were underexpressed at all of the test temperatures were those that encode the ABC transporters, (28) which have been reported to be important in the infection process. (28,29) The transcriptome profile described above shared similarities with that reported by Rastrojo et al, (30) in which L. major promastigotes were exposed to heat shock at 37ºC for two hours. They reported upregulation of genes that encode for several HSPs, which was consistent with our results; in addition, the most downregulated transcript in their study was an ABC transporter, which was also detected in our study, and the amastinencoding genes were also found to be downregulated in both studies.…”

“…They reported upregulation of genes that encode for several HSPs, which was consistent with our results; in addition, the most downregulated transcript in their study was an ABC transporter, which was also detected in our study, and the amastinencoding genes were also found to be downregulated in both studies. (30) These results confirmed that these genes are sensitive to temperature shifts.…”

Transcriptomic signatures of cold adaptation and heat stress in the winter ant (Prenolepis imparis)

“…In our study, we saw greater than a 10-fold increase of expression levels of the gene that encodes for Histone H2A indicating that these proteins are integral to the stress response in P. imparis. Interestingly, increased expression in Histone H2A during heat stress has been found in Leishmania parasites as well [99].…”

Dual transcriptome analysis reveals differential gene expression modulation influenced by Leishmania arginase and host genetic background

“…RNA-seq technology has been used to describe transcriptome profiles of both host and parasite, providing additional knowledge about Leishmania biology and the coordination of host immune responses to infection [23–30]. In this work, we describe gene expression modulation based on dual transcriptome profiles of early in vitro La -WT and La -arg - infections of bone marrow-derived macrophages (BMDMs) from BALB/c or C57BL/6 mice.…”