Towards an understanding of the epigenetics of schistosomes: a comparative epigenomic study

Private Selective Sweeps Identified from Next-Generation Pool-Sequencing Reveal Convergent Pathways under Selection in Two Inbred Schistosoma mansoni Strains

“…It was also previously demonstrated that the diversity of S. mansoni decreased dramatically after the first life cycles of laboratory maintenance, based on the analyses of 15 microsatellite markers [28]. Our global comparative approach of BRE and GH2 strains was thus fully justified by their high level of inbreeding and their well-described compatibility polymorphism at the phenotypic and molecular scales [3], [7], [12], [41], [51], [53]. The use of pool-sequencing allowed for evaluating the genome-wide diversity (SNP distribution and density, SNP frequencies and copy number variations) for each population.…”

“…We had earlier characterized the proteome of two laboratory strains of S. mansoni of different geographic origins [41] and we had characterized their life history traits such as host compatibility in detail [42]. A comparison of the epigenomes of both strains had identified differences in chromatin structure in several loci, among them a metalloprotease of the neutral endopeptidase (NEP) family potentially involved in immuno-modulation of B. glabrata [12]. A preliminary assessment of genetic variation in both strains was performed by sequencing 15 microsatellites previously described [28].…”

“…Twelve corresponded to regions without protein-coding genes, four corresponded to regions with genes encoding hypothetical proteins and three contained known genes. Particularly, we identified the presence of (i) a member of immunophilins, a large group of proteins with peptidyl prolyl-isomerase activity (PPI-ase) that exhibit high specificity in binding to immunosuppressive agents (such as cyclosporine); (ii) a homolog of SPARC (secreted protein acidic and rich in cysteine), a secreted glycoprotein involved in interactions between cells and extracellular matrix [47], both with a higher copy numbers in BRE, and (iii) a M13 family peptidase (that present more copies in GH2), a type II membrane metallo-endopeptidase acting on extracellular substrates [48], belonging to a family of proteases for which another member was identified to be epigenetically different between the two strains [12]. Among the 40 CNV regions checked, one was found in both the Top20 (by size) and in the Top20 (by log2 ratio) (CNVR_270) (Table S4 and S5).…”

“…Compatibility levels of these strains (and several others not presented in this study) are stable after several years of maintenance under laboratory conditions (Supplementary figure S1). This particular feature has made it possible to elucidate partially the molecular basis of the compatibility polymorphism at the global proteomic [3], [4], [7]–[11] and epigenetic scales [12]. In addition, these strains present significant differences in several life history traits, such as chronobiology in cercarial emission [11] and number of mother sporocysts [7].…”

Strongyloides stercoralis and Relatives: Recent Advances in General and Molecular Biology

“…parasitic and free-living females) with radically different body plans, ecological niches, lifespans or developmental fates, all resulting from the same genotype, argues strongly for investigating epigenetic control of developmental fate in Strongyloides spp. Gene regulation at this level has not been studied extensively in parasitic nematodes, but recent work on platyhelminths, including schistosomes, indicates a clear role for epigenetic regulation of reproductive biology in those parasites [68–70]. …”