Central nervous system transcriptome of Biomphalaria alexandrina, an intermediate host for schistosomiasis

Abstract

Objective: Globally, more than 200 million people live at risk of the neglected tropical disease schistosomiasis (or snail fever). Larval schistosomes require the presence of specific snail species that act as intermediate hosts, supporting their multiplication and transformation into forms that can infect humans. This project was designed to generate a transcriptome from the central nervous system (CNS) of Biomphalaria alexandrina, the major intermediate host for Schistosoma mansoni in Egypt.

Results: A transcriptome was generated from five pooled central nervous systems dissected from uninfected specimens of B. alexandrina. Raw Illumina RNA-seq data (~ 20.3 million paired end reads of 150 base pairs length each) generated a transcriptome consisting of 144,213 transcript elements with an N50 contig size of 716 base pairs. Orthologs of 15,246 transcripts and homologs for an additional 16,810 transcripts were identified in the UniProtKB/Swiss-Prot database. The B. alexandrina CNS transcriptome provides a resource for future research exploring parasite-host interactions in a simpler nervous system. Moreover, increased understanding of the neural signaling mechanisms involved in the response of B. alexandrina to infection by S. mansoni larvae could lead to novel and highly specific strategies for the control of snail populations.

Keywords: Biomphalaria alexandrina; CNS; Gastropod; Mollusk; Nile; Schistosoma mansoni; Trematode.

Fig. 1

Source of RNA used to generate transcriptome. a Biomphalaria alexandrina specimen. Calibration bar: 1 mm. b Dissected central nervous system. B g., buccal ganglion; C g., cerebral ganglion; V g., visceral ganglion. Calibration bar: 200 μm

Fig. 2

Histogram of log TPM expression