title: Sensitivity to phosphorus limitation increases with ploidy level in a New Zealand snail.
abstract: Evolutionary and ecological factors that explain natural variation in ploidy level remain poorly understood. One intriguing possibility is that nutrient costs associated with higher per-cell nucleic acid content could differentially influence the fitness of different ploidy levels. Here, we test this hypothesis by determining whether access to phosphorus (P), a main component of nucleic acids, differentially affects growth rate in asexual freshwater snails (Potamopyrgus antipodarum) that differ in ploidy. As expected if larger genomes generate higher dietary P requirements, tetraploid P. antipodarum experienced a more than twofold greater reduction in growth rate in low-P versus high-P conditions relative to triploids. Mirroring these results, tetraploid P. antipodarum also had a significant reduction in body P content under low P relative to high P, whereas triploid body P content was unaffected. Taken together, these results set the stage for the possibility that P availability could influence the distribution and relative frequency of P. antipodarum of different ploidy levels. These findings could be applicable to many other animal taxa featuring ploidy-level variation, which includes many mixed sexual/asexual taxa.
authors.affiliation: Department of Biology, University of Iowa, Iowa City, Iowa. maurine-neiman@uiowa.edu
authors.forename: Maurine
authors.initials: M
authors.lastname: Neiman
authors.forename: Adam D
authors.initials: AD
authors.lastname: Kay
authors.forename: Amy C
authors.initials: AC
authors.lastname: Krist
mesh_terms: D000818:Animals; D016678:Genome / Q000187:drug effects; D006128:Growth / Q000187:drug effects / Q000235:genetics; D010758:Phosphorus / Q000494:pharmacology*; D011003:Ploidies; D012908:Snails / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development
chemical_list: D010758:Phosphorus