Characterisation of the Schistosoma mansoni venom allergen-like (SmVAL) gene family

This study describes the identification and characterization of the Schistosoma mansoni venom allergen-like (SmVAL) proteins, the SCP/TAPS gene family found within the human parasite S. mansoni. 28 SmVALs with complete SCP/TAPS domains were identified within this parasitic trematode and comparison of their predicted protein features and gene structures indicated the presence of two distinct subfamilies (group 1 and group 2). Identification of SCP/TAPS containing proteins in other platyhelminth species demonstrated that both group 1 and group 2 proteins are present throughout the phylum with several SmVAL orthologs detected in both S. japonicum and S. haematobium. While detailed protein feature and phylogenetic analysis across multiple eukaryotic species found SCP/TAPS superfamily members to be present in representative species from four of the six eukaryotic supergroups (Opisthokonta, Amoebozoa, Archaeplastida and Chromalveolata), group 2 proteins were only detected within the Kingdom Animalia. SmVAL quantitative lifecycle expression profiling throughout parasite development demonstrated distinct transcription patterns, including transcripts specifically associated with life-stages involved in definitive host invasion, transcripts restricted to life-stages involved in the invasion of the intermediate host and transcripts ubiquitously expressed. Thorough analysis of SmVAL6 transcript diversity demonstrated a high degree of alternative splicing, including patterns that were statistically significant and developmentally regulated. In summary, this study provides a comprehensive analysis of the SmVAL gene family and presents a framework for understanding diversity within the SCP/TAPS superfamily across phyla. Additionally, the determination of SmVAL gene expression suggests SCP/TAPS proteins are an important protein family associated with schistosome developmental maturation and could, therefore, be viewed as anti-schistosome vaccine and/or drug targets.EThOS - Electronic Theses Online ServiceGBUnited Kingdo