title: The Schistosome Esophagus Is a 'Hotspot' for Microexon and Lysosomal Hydrolase Gene Expression: Implications for Blood Processing.
abstract: BACKGROUND
  The schistosome esophagus is divided into anterior and posterior compartments, each surrounded by a dense cluster of gland cell bodies, the source of distinct secretory vesicles discharged into the lumen to initiate the processing of ingested blood. Erythrocytes are lysed in the lumen, leucocytes are tethered and killed and platelets are eliminated. We know little about the proteins secreted from the two glands that mediate these biological processes.
  
  
  RESULTS
  We have used subtractive RNA-Seq to characterise the complement of genes that are differentially expressed in a head preparation, compared to matched tissues from worm tails. The expression site of representative highlighted genes was then validated using whole munt in situ hybridisation (WISH). Mapping of transcript reads to the S. mansoni genome assembly using Cufflinks identified ~90 genes that were differentially expressed >fourfold in the head preparation; ~50 novel transcripts were also identified by de novo assembly using Trinity. The largest subset (27) of secreted proteins was encoded by microexon genes (MEGs), the most intense focus identified to date. Expression of three (MEGs 12, 16, 17) was confirmed in the anterior gland and five (MEGs 8.1, 9, 11, 15 and 22) in the posterior gland. The other major subset comprised nine lysosomal hydrolases (aspartyl proteases, phospholipases and palmitoyl thioesterase), again localised to the glands.
  
  
  CONCLUSIONS
  A proportion of the MEG-encoded secretory proteins can be classified by their primary structure. We have suggested testable hypotheses about how they might function, in conjunction with the lysosomal hydrolases, to mediate the biological processes that occur in the esophagus lumen. Antibodies bind to the esophageal secretions in both permissive and self-curing hosts, suggesting that the proteins represent a novel panel of untested vaccine candidates. A second major task is to identify which of them can serve as immune targets.
authors.affiliation: Centre for Immunology and Infection, Department of Biology, University of York, Heslington, York, United Kingdom.
authors.forename: R Alan
authors.initials: RA
authors.lastname: Wilson
authors.affiliation: Centre for Immunology and Infection, Department of Biology, University of York, Heslington, York, United Kingdom.|National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China.
authors.forename: Xiao Hong
authors.initials: XH
authors.lastname: Li
authors.affiliation: Genomics and Bioinformatics Laboratory, Department of Biology, University of York, Heslington, York, United Kingdom.
authors.forename: Sandy
authors.initials: S
authors.lastname: MacDonald
authors.affiliation: Genomics and Bioinformatics Laboratory, Department of Biology, University of York, Heslington, York, United Kingdom.
authors.forename: Leandro Xavier
authors.initials: LX
authors.lastname: Neves
authors.affiliation: Centro de Biotecnologia, Instituto Butantan, São Paulo, Brazil.
authors.forename: Juliana
authors.initials: J
authors.lastname: Vitoriano-Souza
authors.affiliation: Centro de Biotecnologia, Instituto Butantan, São Paulo, Brazil.
authors.forename: Luciana C C
authors.initials: LC
authors.lastname: Leite
authors.affiliation: Centro de Biotecnologia, Instituto Butantan, São Paulo, Brazil.|Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz (FIOCRUZ), Rua Waldemar Falcão, Salvador, Bahia, Brasil.
authors.forename: Leonardo P
authors.initials: LP
authors.lastname: Farias
authors.affiliation: Genomics and Bioinformatics Laboratory, Department of Biology, University of York, Heslington, York, United Kingdom.
authors.forename: Sally
authors.initials: S
authors.lastname: James
authors.affiliation: Genomics and Bioinformatics Laboratory, Department of Biology, University of York, Heslington, York, United Kingdom.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Ashton
authors.affiliation: Instituto de Física de São Carlos, Universidade de São Paulo, Sao Carlos, Brasil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: DeMarco
authors.affiliation: Genomics and Bioinformatics Laboratory, Department of Biology, University of York, Heslington, York, United Kingdom.
authors.forename: William
authors.initials: W
authors.lastname: Castro Borges
mesh_terms: D000818:Animals; D004947:Esophagus / Q000201:enzymology; D005260:Female; D020869:Gene Expression Profiling; D015801:Helminth Proteins / Q000096:biosynthesis* / Q000235:genetics; D006867:Hydrolases / Q000096:biosynthesis* / Q000235:genetics; D017403:In Situ Hybridization; D008297:Male; D008807:Mice, Inbred BALB C; D012547:Schistosoma / Q000201:enzymology*
chemical_list: D015801:Helminth Proteins; D006867:Hydrolases