Combinatory Microarray and SuperSAGE Analyses Identify Pairing-Dependently Transcribed Genes in Schistosoma mansoni Males, Including Follistatin

Abstract

BackgroundSchistosomiasis is a disease of world-wide importance and is caused by parasitic flatworms of the genus Schistosoma. These parasites exhibit a unique reproduction biology as the female's sexual maturation depends on a constant pairing-contact to the male. Pairing leads to gonad differentiation in the female, and even gene expression of some gonad-associated genes is controlled by pairing. In contrast, no morphological changes have been observed in males, although first data indicated an effect of pairing also on gene transcription in males.Methodology/Principal FindingsTo investigate the influence of pairing on males, we performed a combinatory approach applying SuperSAGE and microarray hybridization, generating the most comprehensive data-set on differential transcription available to date. Of 6,326 sense transcripts detected by both analyses, 29 were significantly differentially transcribed. Besides mutual confirmation, the two methods complemented each other as shown by data comparison and real-time PCR, which revealed a number of genes with consistent regulation across all methods. One of the candidate genes, follistatin of S. mansoni (SmFst) was characterized in more detail by in situ hybridization and yeast two-hybrid (Y2H) interaction analyses with potential binding partners.Conclusions/SignificanceBeyond confirming previously hypothesized differences in metabolic processes between pairing-experienced (EM) and pairing-unexperienced males (UM), our data indicate that neuronal processes are involved in male-female interaction but also TGFβ-signaling. One candidate revealing significant down-regulation in EM was the TGFβ-pathway controlling molecule follistatin (SmFst). First functional analyses demonstrated SmFst interaction with the S. mansoni TGFβ-receptor agonists inhibin/activin (SmInAct) and bone morphogenic protein (SmBMP), and all molecules colocalized in the testes. This indicates a yet unknown role of the TGFβ-pathway for schistosome biology leading to male competence and a possible influence of pairing on the male gonad.

Tissue Transglutaminase‐Regulated Transformed Growth Factor‐β1 in the Parasite Links Schistosoma japonicum Infection with Liver Fibrosis

“…Hirata et al [ 24 ] revealed the expression of TGF- β 1-, TGF- β 2-, and TGF- β 3-like molecules in Sj . Some members of TGF- β superfamily, including InACT, BMP, receptors of TGF- β , and Smad1, Smad2, and Smad4 and other signaling pathway-associated molecules have been identified in Schistosoma [ 14 – 22 ]. In addition, tTG is the principal enzyme controlling TGF- β maturation rate [ 29 – 31 ].…”

“…The activated TGF- β 1 binding with specific receptors in the cell membrane through the Smad signal transduction pathways plays the biological role [ 13 ]. Some members of TGF- β superfamily, including InACT, BMP, receptors of TGF- β [ 14 – 18 ] and Smad1, Smad2, and Smad4, and their signaling pathway-associated molecules have been identified in Schistosoma [ 19 – 22 ]. InAct plays important roles in Sm development and embryogenesis [ 23 ].…”

Schistosoma mansoni Egg, Adult Male and Female Comparative Gene Expression Analysis and Identification of Novel Genes by RNA-Seq

“…The comparison of S . mansoni male and female adult worm transcriptomes was performed only using oligonucleotide microarrays, which use short (60 nt) probes to detect known genes [ 7 ], and using Serial Analysis of Gene Expression (SAGE), which sequences short (10–14 bp) SAGE tags [ 8 ] that need to be matched to previously known full-length gene sequences to unequivocally assign their identity. In addition, the egg transcriptome was analyzed only once using Sanger sequencing [ 5 ], and no additional studies have been performed on this life-cycle stage using unbiased, large-scale sequencing.…”

Preliminary characterization and expression of Vasa-like gene in Schistosoma japonicum

“…Disease symptoms are predominantly caused by the host immune response to schistosome eggs and the evoked granulomatous reaction (Wilson et al 2007). Recently, many studies have focused on mechanisms of schistosome reproductive biology, leading to the identification of proteins essential for worm reproduction and egg development (Leutner et al 2013;Liu et al 2010;Mann et al 2014;Ren et al 2013;Xu et al 2014).…”