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Biomphalaria snails serve as vectors for Schistosoma mansoni, a trematode causing human schistosomiasis. Control of Schistosoma mansoni involves chemotherapy of affected people, but new control methods built on improved understanding of schistosome-snail interactions are needed. My dissertation applies molecular and bioinformatics approaches to understand such interactions. Chapter 1 shows that significant differences exist among Biomphalaria species in Africa with respect to their ability to support schistosome development. Chapters 2 and 3 reveal the transcriptional responses of Biomphalaria glabrata susceptible (SUS) or resistant (RES) to Schistosoma mansoni. Chapter 2 identifies a new family of snail immune factors, the AIG family of GTPases, and highlights striking differences between SUS and RES snails in their responses to Schistosoma mansoni. Chapter 3 examines the snail FReD gene family and identifies a prominent response to Schistosoma mansoni in RES but not SUS snails. This dissertation identifies snail molecules potentially conferring resistance against schistosomes for future control efforts.

Biomphalaria snails serve as vectors for Schistosoma mansoni, a trematode causing human schistosomiasis. Control of Schistosoma mansoni involves chemotherapy of affected people, but new control methods built on improved understanding of schistosome-snail interactions are needed. My dissertation applies molecular and bioinformatics approaches to understand such interactions. Chapter 1 shows that significant differences exist among Biomphalaria species in Africa with respect to their ability to support schistosome development. Chapters 2 and 3 reveal the transcriptional responses of Biomphalaria glabrata susceptible (SUS) or resistant (RES) to Schistosoma mansoni. Chapter 2 identifies a new family of snail immune factors, the AIG family of GTPases, and highlights striking differences between SUS and RES snails in their responses to Schistosoma mansoni. Chapter 3 examines the snail FReD gene family and identifies a prominent response to Schistosoma mansoni in RES but not SUS snails. This dissertation identifies snail molecules potentially conferring resistance against schistosomes for future control efforts.

The Neotropical freshwater snail, Biomphalaria glabrata is a major intermediate host of the parasite Schistosoma mansoni, causative agent of human intestinal schistosomiasis. Disease control efforts consist mainly of mass drug treatment but it is recognized that targeting of the snail vector is essential to prevent parasite transmission that leads to rapid (re)infections. This dissertation combines the knowledge of basic snail biology with modern molecular techniques including protein analysis, next-generation sequencing, proteomics, qRT-PCR and RNA interference to: (1) characterize hemocyanin-like genes in B. glabrata, in particular with further description of the egg mass fluid (EMF) protein hemocyanin-like 1 (Hcl-1), (2) investigate phylogenetic distribution and evolutionary origin of Hcl-1 among snails of the family Planorbidae and close sister-taxa and (3) provide insight into the function Hcl-1, as an EMF protein, plays in B. glabrata eggs. Results indicate there are two hemocyanin-like genes (Hcl-1 and Hcl-2) in B. glabrata with Hcl-1 being present in all subgroups of the family Planorbidae tested, but not outside of this family. We report unique structural features of Hcl-1 when compared to respiratory gastropod hemocyanins and determine that Hcl-1 is important for sucessful reproductive output of B. glabrata snails. Here, we provide an insight into unique planorbid snail biology that with further investigation has the potential of being exploited to control planorbid snails, which include several species that serve as intermediate host for human infecting schistosomes.

The Neotropical freshwater snail, Biomphalaria glabrata is a major intermediate host of the parasite Schistosoma mansoni, causative agent of human intestinal schistosomiasis. Disease control efforts consist mainly of mass drug treatment but it is recognized that targeting of the snail vector is essential to prevent parasite transmission that leads to rapid (re)infections. This dissertation combines the knowledge of basic snail biology with modern molecular techniques including protein analysis, next-generation sequencing, proteomics, qRT-PCR and RNA interference to: (1) characterize hemocyanin-like genes in B. glabrata, in particular with further description of the egg mass fluid (EMF) protein hemocyanin-like 1 (Hcl-1), (2) investigate phylogenetic distribution and evolutionary origin of Hcl-1 among snails of the family Planorbidae and close sister-taxa and (3) provide insight into the function Hcl-1, as an EMF protein, plays in B. glabrata eggs. Results indicate there are two hemocyanin-like genes (Hcl-1 and Hcl-2) in B. glabrata with Hcl-1 being present in all subgroups of the family Planorbidae tested, but not outside of this family. We report unique structural features of Hcl-1 when compared to respiratory gastropod hemocyanins and determine that Hcl-1 is important for sucessful reproductive output of B. glabrata snails. Here, we provide an insight into unique planorbid snail biology that with further investigation has the potential of being exploited to control planorbid snails, which include several species that serve as intermediate host for human infecting schistosomes.