@article{fdi:010083881,
  title = {{M}orphological and genomic characterisation of the {S}chistosoma hybrid infecting humans in {E}urope reveals admixture between {S}chistosoma haematobium and {S}chistosoma bovis},
  author = {{K}incaid-{S}mith, {J}ulien and {T}racey, {A}. and {A}ugusto, {R}. {D}. and {B}ulla, {I}. and {H}olroyd, {N}. and {R}ognon, {A}. and {R}ey, {O}. and {C}haparro, {C}. and {O}leaga, {A}. and {M}as-{C}oma, {S}. and {A}llienne, {J}. {F}. and {G}runau, {C}. and {B}erriman, {M}. and {B}oissier, {J}. and {T}oulza, {E}.},
  editor = {},
  language = {{ENG}},
  abstract = {{S}chistosomes cause schistosomiasis, the world's second most important parasitic disease after malaria in terms of public health and social-economic impacts. {A} peculiar feature of these dioecious parasites is their ability to produce viable and fertile hybrid offspring. {O}riginally only present in the tropics, schistosomiasis is now also endemic in southern {E}urope. {B}ased on the analysis of two genetic markers the {E}uropean schistosomes had previously been identified as hybrids between the livestock- and the human-infective species {S}chistosoma bovis and {S}chistosoma haematobium, respectively. {H}ere, using {P}ac{B}io long-read sequencing technology we performed genome assembly improvement and annotation of {S}. bovis, one of the parental species for which no satisfactory genome assembly was available. {W}e then describe the whole genome introgression levels of the hybrid schistosomes, their morphometric parameters (eggs and adult worms) and their compatibility with two {E}uropean snail strains used as vectors ({B}ulinus truncatus and {P}lanorbarius metidjensis). {S}chistosome-snail compatibility is a key parameter for the parasites life cycle progression, and thus the capability of the parasite to establish in a given area. {O}ur results show that this {S}chistosoma hybrid is strongly introgressed genetically, composed of 77% {S}. haematobium and 23% {S}. bovis origin. {T}his genomic admixture suggests an ancient hybridization event and subsequent backcrosses with the human-specific species, {S}. haematobium, before its introduction in {C}orsica. {W}e also show that egg morphology (commonly used as a species diagnostic) does not allow for accurate hybrid identification while genetic tests do. {A}uthor summary : {I}n 2013, schistosomiasis reached {S}outhern {E}urope. {S}ince then, endemic infections were recurrently identified clearly indicating that the parasite has settled and established locally. {U}sing two molecular markers, we had previously demonstrated that the parasite was a hybrid between {S}chistosoma haematobium and {S}chistosoma bovis, two species known to infect humans and livestock, respectively. {N}evertheless, this method has very low resolution and is not informative for determining the origins and the mechanisms of hybridization events, e.g. if the hybrid had been recently generated in {C}orsica or long before it's introduction. {T}he genome-wide sequencing approach, used in this study, allowed us to reveal genomic admixture suggesting that these hybrids are the result of ancient crossing events between {S}. haematobium and {S}. bovis, with subsequent backcrossing with {S}. haematobium. {T}his introgression has prevented compatibility with {P}. metidjensis snail vectors, which are specific to {S}. bovis. {A}dditionally, whether in {A}frica or in {E}urope, a clear discrepancy exists between the egg shape usually used for species identification and the genomic composition of schistosomes. {T}herefore, egg shape cannot be used as a good indicator for hybrid detection. {K}nowing the phenotypic traits and the genetic features of such hybrids may have important implications in terms of diagnostics and disease management either through vector control strategies or treatment of patients.},
  keywords = {{EUROPE} ; {CORSE}},
  booktitle = {},
  journal = {{PL}o{S} {N}eglected {T}ropical {D}iseases},
  volume = {15},
  numero = {12},
  pages = {e0010062 [18 p.]},
  ISSN = {1935-2735},
  year = {2021},
  DOI = {10.1371/journal.pntd.0010062},
  URL = {https://www.documentation.ird.fr/hor/fdi:010083881},
}