03752nas a2200217   4500008004100000022001400041245016000055210006900215260001600284490000700300520299800307100001403305700001903319700002003338700002703358700002003385700003603405700002803441700001603469856004903485       2022                        eng d  a1756-330500aLarge-scale and small-scale population genetic structure of the medically important gastropod species <i>Bulinus truncatus</i> (Gastropoda, Heterobranchia)0 aLargescale and smallscale population genetic structure of the me  cSep-19-20220 v153 a<p><jats title="">Abstract</jats><jats sec=""> <jats title="">Background</jats> <jats p="">Gastropod snails remain strongly understudied, despite their important role in transmitting parasitic diseases. Knowledge of their distribution and population dynamics increases our understanding of the processes driving disease transmission. We report the first study to use high-throughput sequencing (HTS) to elucidate the population genetic structure of the hermaphroditic snail <jats italic="">Bulinus truncatus</jats> (Gastropoda, Heterobranchia) on a regional (17&ndash;150&nbsp;km) and inter-regional (1000&ndash;5400&nbsp;km) scale. This snail species acts as an intermediate host of <jats italic="">Schistosoma haematobium</jats> and <jats italic="">Schistosoma bovis</jats>, which cause human and animal schistosomiasis respectively<jats italic="">.</jats></jats> </jats><jats sec=""> <jats title="">Methods</jats> <jats p=""><jats italic="">Bulinus truncatus</jats> snails were collected in Senegal, Cameroon, Egypt and France and identified through DNA barcoding. A single-end genotyping-by-sequencing (GBS) library, comprising 87 snail specimens from the respective countries, was built and sequenced on an Illumina HiSeq 2000 platform. Reads were mapped against <jats italic="">S. bovis</jats> and <jats italic="">S. haematobium</jats> reference genomes to identify schistosome infections, and single nucleotide polymorphisms (SNPs) were scored using the Stacks pipeline. These SNPs were used to estimate genetic diversity, assess population structure and construct phylogenetic trees of <jats italic="">B. truncatus</jats>.</jats> </jats><jats sec=""> <jats title="">Results</jats> <jats p="">A total of 10,750 SNPs were scored and used in downstream analyses. The phylogenetic analysis identified five clades, each consisting of snails from a single country but with two distinct clades within Senegal. Genetic diversity was low in all populations, reflecting high selfing rates, but varied between locations due to habitat variability. Significant genetic differentiation and isolation by distance patterns were observed at both spatial scales, indicating that gene flow is not strong enough to counteract the effects of population bottlenecks, high selfing rates and genetic drift. Remarkably, the population genetic differentiation on a regional scale (i.e. within Senegal) was as large as that between populations on an inter-regional scale. The blind GBS technique was able to pick up parasite DNA in snail tissue, demonstrating the potential of HTS techniques to further elucidate the role of snail species in parasite transmission.</jats> </jats><jats sec=""> <jats title="">Conclusions</jats> <jats p="">HTS techniques offer a valuable toolbox to further investigate the population genetic patterns of intermediate schistosome host snails and the role of snail species in parasite transmission.</jats> </jats><jats sec=""> <jats title="">Graphical Abstract</jats> </jats></p>
1 aMaes, Tim1 aDe Corte, Zoë1 aVangestel, Carl1 aVirgilio, Massimiliano1 aSmitz, Nathalie1 aDjuikwo-Teukeng, Félicité, F.1 aPapadaki, Maria, Ioanna1 aHuyse, Tine  uhttp://dx.doi.org/10.1186/s13071-022-05445-x