Insilco Analysis of Leishmania donovani Genome to Understand its Gene Expression Regulation

Abstract Leishmania donovani is an obligate intracellular parasite of human that causes a dreadful visceral infection that may involve liver, spleen, bone marrow, and lymph nodes. The specific feature of the species influences its genetics. Changes in parasite adaptation to different environment, development of silent genes and parasite progression through its lifecycle may be determined by transcriptional organizations affecting its gene expression. Hence, Insilco analysis of Leishmania donovani BPK282A1 genome was performed to predict the promoter and regulatory elements involved in gene expression. Forty putative genes of Leishmania donovani BPK282A1 genes were obtained from National Center for Biotechnology Information and investigated using bioinformatic tools, such as Neural Network Promoter Prediction, MEME suite, CpG island finder, GOMo and CLC Genomics Workbench. In this analysis, the number of Transcription Start Sites (TSSs) in promoter regions of Leishmania donovani BPK282A1 varied greatly between 1 and 4 with majority (60%) of them having two or more TSSs. The study also revealed seven candidate motifs in the promoter regions of the gene. The common promoter motif for all Leishmania donovani BPK282A1 genes was MI with an E-value of 4.0e-116. Six of the identified motifs were related to zinc finger proteins that bind to the GC-rich regions in DNA. The study also revealed that most of both the promoter and the gene body regions contain at least one CpG island. Restriction analysis using MspI enzyme showed that Leishmania donovani BPK282A1 genes were CpG rich. In conclusion, the investigation unfolded expression regulation of Leishmania donovani BPK282A1 genes contributing to development of a robust drug and vaccine that targets the regulatory regions.