Spatially explicit genetic structure in the freshwater sponge Ephydatia fluviatilis (Linnaeus, 1759) within the framework of the monopolisation hypothesis

Abstract

An apparent paradox is known for crustaceans, rotifers and bryozoans living in inland small fluviatilis (Linnaeus, 1759). We expected that system genetic variability would follow enclave distributions, no clear phylogeographical patterns would be present, and nearby unconnected water bodies would show markedly different populations for this new model too. We analysed the ribosomal internal transcribed spacer regions 5.8S-ITS2-28S, the D3 domain of 28S subunit, the mitochondrial Cytochrome c Oxidase I (COI) and ten specific microsatellite markers of nine Italian and one Hungarian populations. Mitochondrial and nuclear sequences showed no or very low genetic polymorphism, whereas high levels of differ-entiation among populations and a significant polymorphism were observed using microsatellites. Microsatellite loci also showed a high proportion of private alleles for each population and an overall correlation between geographic and genetic distances among populations. All the expectations from the monopolisation hypothesis seemingly were confirmed for the analysed sponge.

Study of microsatellite cross-species specificity in freshwater sponge families Lubomirskiidae and Spongillidae

“…Microsatellite markers developed and successfully used for population genetic studies of E.fluviatilis (Anderson et al, 2010;Lucentini et al, 2013;Li et al, 2018) are not suitable for population genetic studies of the E.muelleri and L.baikalensis species.…”

“…Due to the loss of this method of asexual reproduction, a significant decrease in the representation of clones in the populations of Baikal sponges and a change in the population structure are expected. Research on the population genetic structure of freshwater sponges is limited to a few studies of Ephydatia fluviatilis (Lucentini et al, 2013;Li et al, 2018). In this regard, the study of the population structure of Lubomirskia baikalensis and E.muelleri is highly relevant.…”

“…Microsatellite markers are widely used for study the population structure of marine (Blanquer and Uriz, 2010;Dailianis et al, 2011;Pérez-Portela et al, 2015;Riesgo et al, 2019) and freshwater (Lucentini et al, 2013;Li et al, 2018) sponges. The study of the genetic diversity of endemic Baikal sponges at the population level is fundamentally important for the conservation of species, especially in the conditions of mass mortality observed in Lake Baikal during the past decade (Kaluzhnaya and Itskovich, 2015;Denikina et al, 2016;Itskovich et al, 2018;Khanaev et al, 2018;Kulakova et al, 2018;Belikov et al, 2019).…”

Analysis of Cross-Species Usability of Microsatellite Markers for Baikal Endemic Sponges

“…Despite the availability of published genomic data for Lubomirskia baikalensis [10], the population structure of this species has not been studied before. However, such a study is of great interest, since it is not known whether the sponges living in different basins of the lake make up different populations, how the loss of the ability to form gemmules affected the population structure compared to cosmopolitan freshwater sponges [11,12]; did the mass diseases and mortality of sponges observed in Baikal over the last decade [13][14][15][16][17][18] affected on the structure of populations in mostly diseased areas.…”

“…To solve these questions, it is necessary to select molecular genetic markers suitable for population analysis. Microsatellite markers have been successfully used for marine and cosmopolitan freshwater sponges [11,12,[19][20][21][22] these are short tandem repeats with higher evolutionary rates than other regions of the genome. Several approaches can be used to develop microsatellite markers.…”