| Abstract | An apparent paradox is known for crustaceans, rotifers and bryozoans living in inland small water bodies: a potential for wide distribution due to the presence of resting stages is coupled with marked genetic differences between nearby water bodies, with enclave distributions masking clear phylogeographic patterns. According to the monopolisation hypothesis, this is due to the accumulation of resting stages, monopolising each water body. Freshwater sponges could represent a useful system to assess the generality of the monopolisation hypothesis: these organisms i) live in the same habitats as crustaceans, rotifers and bryozoans, ii) produce resting stages that can accumulate, and iii) have indeed a wide distribution. Currently, no studies on spatially explicit genetic differentiation on freshwater sponges are available. The aim of the present study is to provide additional empirical evidence in support of the generality of the scenario for small aquatic animals with resting stages by analysing genetic diversity at different spatial scales for an additional model system, the freshwater sponge ephydatia 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 differentiation 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. |
| Text | 281534 2013 10.4081/jlimnol.2013.e14 ISI Web of Science WOS 000324041400014 ephydatia fluviatilis monopolisation hypothesis microsatellites 5.8 ITS2 28S Cytochrome c Oxidase I Spatially explicit genetic structure in the freshwater sponge Ephydatia fluviatilis Linnaeus, 1759 within the framework of the monopolisation hypothesis Livia Lucentini; Lilia Gigliarelli; Maria Elena Puletti; Antonella Palomba; Aurora Caldelli; Diego Fontaneto; Fausto Panara Lucentini, Livia dipartimento di biologia cellulare e ambientale, universita di Perugia, via Pascoli 1, 06123, Perugia, italy Gigliarelli, Lilia dipartimento di biologia cellulare e ambientale, universita di Perugia, via Pascoli 1, 06123, Perugia, italy Puletti, Maria Elena dipartimento di biologia cellulare e ambientale, universita di Perugia, via Pascoli 1, 06123, Perugia, italy Palomba, Antonella dipartimento di Specialita Medico chirurgiche e Sanita Pubblica, universita di Perugia, via del Giochetto, 06123, Perugia, italy Caldelli, Aurora Dipartimento di biologia cellulare e ambientale, universita di Perugia, via Pascoli 1, 06123, Perugia, italy Fontaneto, Diego CNR ISE, Pallanza Verbania Panara, Fausto Dipartimento di biologia cellulare e ambientale, universita di Perugia, via Pascoli 1, 06123, Perugia, italy An apparent paradox is known for crustaceans, rotifers and bryozoans living in inland small water bodies a potential for wide distribution due to the presence of resting stages is coupled with marked genetic differences between nearby water bodies, with enclave distributions masking clear phylogeographic patterns. According to the monopolisation hypothesis, this is due to the accumulation of resting stages, monopolising each water body. Freshwater sponges could represent a useful system to assess the generality of the monopolisation hypothesis these organisms i live in the same habitats as crustaceans, rotifers and bryozoans, ii produce resting stages that can accumulate, and iii have indeed a wide distribution. Currently, no studies on spatially explicit genetic differentiation on freshwater sponges are available. The aim of the present study is to provide additional empirical evidence in support of the generality of the scenario for small aquatic animals with resting stages by analysing genetic diversity at different spatial scales for an additional model system, the freshwater sponge ephydatia 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 differentiation 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. 72 Published version Articolo 2013_J_Limnol_72_1_172_181.pdf Articolo in rivista Istituto per lo Studio degli Ecosistemi. 1129 5767 Journal of limnology Testo stamp. Journal of limnology Testo stamp. J. limnol. Testo stamp. Journal of limnology. Testo stamp. diego.fontaneto FONTANETO DIEGO TA.P04.016.004 Ecologia teorica e applicata degli ecosistemi acquatici |
