Genome and transcriptome studies of the protozoan parasites Trypanosoma cruzi and Giardia intestinalis

Abstract

Trypanosoma cruzi and Giardia intestinalis are two human pathogens and protozoan parasites responsible for the diseases Chagas disease and giardiasis, respectively. Both diseases cause suffering and illness in several million individuals. The former disease occurs primarily in South America and Central America, and the latter disease occurs worldwide. Current therapeutics are toxic and lack efficacy, and potential vaccines are far from the market. Increased knowledge about the biology of these parasites is essential for drug and vaccine development, and new diagnostic tests. In this thesis, high-throughput sequencing was applied together with extensive bioinformatic analyses to yield insights into the biology and evolution of Trypanosoma cruzi and Giardia intestinalis. Bioinformatics analysis of DNA and RNA sequences was performed to identify features that may be of importance for parasite biology and functional characterization. This thesis is based on five papers (i-v). Paper i and ii describe comparative genome studies of three distinct genotypes of Giardia intestinalis (A, B and E). Paper iii describes a genome comparison of the human infecting Trypanosoma cruzi with the bat-restricted subspecies Trypanosoma cruzi marinkellei. Paper iv describes the repertoire of small non-coding RNAs in Trypanosoma cruzi epimastigotes. Paper v describes transcriptome analysis using paired-end RNA-Seq of three distinct genotypes of Giardia intestinalis (A, B and E).