Jones, Ben (2018) Genomic analysis of schistosomes of Southeast Asia. (MSc(R) thesis), Kingston University, .

Abstract

'Schistosoma spindale' and 'Schistosoma indicum' are two species of cattle infecting trematodes of the 'Schistosoma indicum' group that are widespread across Southeast Asia that can cause significant pathology to livestock. The genome of 'S. spindale' and 'S. indicum' were assembled and genetics analyses were carried out. Mitichondrial genomic analysis was undertaken to identify the levels of diversity within the 'S. indicum' group. Results showed high levels of diversity with the 'S inficum' group and evidence of functional changes in mitochondrial genes indicated adaptation to environmental changes that may have caused speciation events in 'S. spindale' between 2 and 3 million years ago. Despite the high levels of diversity in the mitochondrial genomes, tests on the sex chromosome and reproductive proteins were unable to find evidence of major isolating speciation barriers between 'S. spindale' and 'S indicum'. The identification of divergent chromosomal strata on the Z chromosome indicates that whilst there are no major isolating barriers in place yet, the sex chromosomes are diverging between species. In an aim to assess methods of combating schistosomiasis analyses were performed on proteins that are known to directly interact with anthelminthic compounds commonly used against fluke infection. In-silico drug binding experiments illustrated that praziquantel would be the most effective drug against 'S. spindale' and 'S. indicum'. Interestingly analyses suggested that oxamniquine may be effective against 'S. indicum' but not 'S. spindale'. The final analyses identified a number of immune epitopes in proteins that could be potential vaccine targets. Of interest was the prediction of numerous major histocompatability complex class II binding sites, which indicates a genetically determined immune response to these parasites. The novel information from this study has provided a starting place for more in-depth investigations of these neglected parasites that could have implications for many 'Schistosoma' species.

Actions (Repository Editors)

Item Control Page