03752nas a2200217 4500008004100000022001400041245016000055210006900215260001600284490000700300520299800307100001403305700001903319700002003338700002703358700002003385700003603405700002803441700001603469856004903485 2022 eng d a1756-330500aLarge-scale and small-scale population genetic structure of the medically important gastropod species Bulinus truncatus (Gastropoda, Heterobranchia)0 aLargescale and smallscale population genetic structure of the me cSep-19-20220 v153 a

Abstract Background 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 Bulinus truncatus (Gastropoda, Heterobranchia) on a regional (17–150 km) and inter-regional (1000–5400 km) scale. This snail species acts as an intermediate host of Schistosoma haematobium and Schistosoma bovis, which cause human and animal schistosomiasis respectively. Methods Bulinus truncatus 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 S. bovis and S. haematobium 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 B. truncatus. Results 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. Conclusions 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. Graphical Abstract

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-x01125nas a2200313 4500008004100000022002500041245022600066210006900292260001600361300001800377490000700395100001900402700002000421700001600441700003200457700002900489700002700518700003000545700001800575700001600593700001900609700001800628700002800646700002100674700003200695700002800727700001600755856004000771 2022 eng d a0962-1083, 1365-294X00aPopulation genomics of introduced Nile tilapia Oreochromis niloticus (Linnaeus, 1758) in the Democratic Republic of the Congo: Repeated introductions since colonial times with multiple sources0 aPopulation genomics of introduced Nile tilapia iOreochromis nilo cMay-07-2022 a3304 – 33220 v311 aGeraerts, Mare1 aVangestel, Carl1 aArtois, Tom1 aFernandes, Jorge, Manuel de1 aJorissen, Michiel, W. P.1 aManda, Auguste, Chocha1 aMizani, Célestin, Danadu1 aSmeets, Karen1 aSnoeks, Jos1 aSonet, Gontran1 aTingbao, Yang1 aVan Steenberge, Maarten1 aVreven, Emmanuel1 aWamuini, Soleil, Lunkayilak1 aVanhove, Maarten, P. M.1 aHuyse, Tine uhttp://dx.doi.org/10.1111/mec.16479