| description |
The leishmaniases are complex neglected diseases caused by protozoan parasites of the genus Leishmania. Cutaneous leishmaniasis is the most common clinical manifestation around the world and in the New World the main etiological agent is Leishmania braziliensis. In recent studies, chromosome and gene copy number variations (CNVs) as well as transcriptomic changes have been highlighted as some mechanisms used by Leishmania species to adapt to environmental changes. However, no studies have described the impact of temperature shifts across the genome and transcriptome of Leishmania promastigotes. For these reasons the aim of this study is determine the effect of short-term temperature shifts in L. braziliensis promastigotes in vitro. Growth curves and genome and transcriptome sequencing (DNA-Seq and RNA-Seq) of L. braziliensis promastigotes were done from cultures subjected to three different temperatures, 24, 28, and 30°C; then, the resulting sequences were compared with the results obtained at the control temperature (26°C). Our results showed that the temperature shifts impacted the L. braziliensis proliferation, especially, at 30°C. Also, we did not find changes in the somy, SNPs and indels on the DNA among the three temperatures and only around 3% of the genes had significant copy number variations (CNVs) at each temperature, however, there was not a correlation between these genes variations and their transcripts. On the other hand, the transcriptome profiles demonstrated a fast response to the heat stress, in which the most relevant genes encode to amastin surface-like proteins, heat shock proteins (HSPs) and transport proteins which could be related with a direct response to this abiotic factor. This study provides evidence that L. braziliensis promastigotes exhibit a short-term response to heat stress, generating changes at gene CNVs and an up- or downregulation of a range of genes associated with different stimulus and other fundamental processes which might be important in their adaptation and their surviving to a temperature shift. These results gave us a first view of Leishmania genomic and transcriptomic short time adaptative capacity to temperature stress conditions, increasing the awareness of the biology of this important parasite in New World. |