01825nas a2200157 4500008004100000245011700041210006900158300000700227490000700234520129900241100001701540700001901557700001701576700002501593856004901618 2011 eng d00aMolecular markers to characterize the hermaphroditic reproductive system of the planarian Schmidtea mediterranea0 aMolecular markers to characterize the hermaphroditic reproductiv a690 v113 a

Background The freshwater planarian Schmidtea mediterranea exhibits two distinct reproductive modes. Individuals of the sexual strain are cross-fertilizing hermaphrodites with reproductive organs that develop post-embryonically. By contrast, individuals of the asexual strain reproduce exclusively by transverse fission and fail to develop reproductive organs. These different reproductive strains are associated with distinct karyotypes, making S. mediterranea a useful model for studying germline development and sexual differentiation. Results To identify genes expressed differentially between these strains, we performed microarray analyses and identified >800 genes that were upregulated in the sexual planarian. From these, we characterized 24 genes by fluorescent in situ hybridization (FISH), revealing their expression in male germ cells or accessory reproductive organs. To identify additional markers of the planarian reproductive system, we also used immuno- and fluorescent lectin staining, identifying several antibodies and lectins that labeled structures associated with reproductive organs. Conclusions Collectively, these cell-type specific markers will enable future efforts to characterize genes that are important for reproductive development in the planarian.

1 aChong, Tracy1 aStary, Joel, M1 aWang, Yuying1 aNewmark, Phillip, A. uhttp://www.biomedcentral.com/1471-213X/11/6900574nas a2200157 4500008004100000245010700041210006900148490000700217100002100224700002600245700002400271700001600295700002000311700001900331856006600350 2011 eng d00aSchmidtea mediterranea phylogeography: an old species surviving on a few Mediterranean islands?0 aiSchmidtea mediterraneai phylogeography an old species surviving0 v111 aLázaro, Eva, M.1 aHarrath, Abdul, Halim1 aStocchino, Giacinta1 aPala, Maria1 aBaguñà, Jaume1 aRiutort, Marta uhttp://www.biomedcentral.com/content/pdf/1471-2148-11-274.pdf02247nas a2200133 4500008004100000245014200041210006900183300000700252490000600259520173700265100002202002700002002024856006902044 2011 eng d00aSex-inducing effect of a hydrophilic fraction on reproductive switching in the planarian Dugesia ryukyuensis (Seriata, Tricladida)0 aSexinducing effect of a hydrophilic fraction on reproductive swi a230 v83 a

Background The mechanisms underlying the switching from an asexual to a sexual mode of reproduction, and vice versa, remain unknown in metazoans. In planarians, asexual worms acquire cryptic sexuality when fed with sexual worms, indicating that sexual worms contain a sex-inducing substance. Although such a chemical compound will provide clues about the mechanisms underlying the switching, information on the sex-inducing substance is poor. In order to identify this substance, we have established an assay system for sexual induction in asexual worms of Dugesia ryukyuensis by feeding them with sexual worms. Here, we carried out an isolation study on the sex-inducing substance using this assay system. Results After centrifugation of sexual worms homogenised in saline solution, we found that not only did the precipitate have a sex-inducing effect on the asexual worms, which has been shown previously, but the cytosolic fraction did as well. We confirmed that the sex-inducing activity in the cytosolic fraction was recovered in a hydrophilic fraction separated on an octadecylsilane (ODS) column. We showed that the sex-inducing substance in the hydrophilic fraction is papain-resistant and a putative low-molecular-weight compound of less than 500. We also suggest the presence of an enhancer of sexual induction with a molecular weight (MW) of more than 5 K in the hydrophilic fraction. Conclusion Our experiments showed the existence of a sex-inducing substance and an enhancer of sex-induction in a hydrophilic fraction, and a putative hydrophobic sex-inducing substance in the precipitate. Sexual induction in the asexual worms might be triggered by additive or synergistic effects of these chemical compounds.

1 aKobayashi, Kazuya1 aHoshi, Motonori uhttp://www.frontiersinzoology.com/content/pdf/1742-9994-8-23.pdf01493nas a2200157 4500008004100000245009500041210006900136260001200205300001000217490000800227520095700235100002301192700002101215700002301236856007601259 2011 eng d00aClonogenic neoblasts are pluripotent adult stem cells that underlie planarian regeneration0 aClonogenic neoblasts are pluripotent adult stem cells that under c05/2011 a811-60 v3323 a

Pluripotent cells in the embryo can generate all cell types, but lineage-restricted cells are generally thought to replenish adult tissues. Planarians are flatworms and regenerate from tiny body fragments, a process requiring a population of proliferating cells (neoblasts). Whether regeneration is accomplished by pluripotent cells or by the collective activity of multiple lineage-restricted cell types is unknown. We used ionizing radiation and single-cell transplantation to identify neoblasts that can form large descendant-cell colonies in vivo. These clonogenic neoblasts (cNeoblasts) produce cells that differentiate into neuronal, intestinal, and other known postmitotic cell types and are distributed throughout the body. Single transplanted cNeoblasts restored regeneration in lethally irradiated hosts. We conclude that broadly distributed, adult pluripotent stem cells underlie the remarkable regenerative abilities of planarians.

1 aWagner, Daniel, E.1 aWang, Irving, E.1 aReddien, Peter, W. uhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338249/pdf/nihms355177.pdf02075nas a2200181 4500008004100000022001400041245013000055210006900185260001200254300001200266490000800278520146500286100002001751700003001771700002001801700002001821856005201841 2011 eng d a1863-913500aPlanarian (Dugesia polychroa) predation on freshwater gastropod eggs depends on prey species, clutch morphology, and egg size0 aPlanarian Dugesia polychroa predation on freshwater gastropod eg c03/2011 a325-3390 v1783 a

Though triclad planarias could limit littoral snail recruitment by preying on eggs with their muscular ventral pharynx, planarian predation on eggs has never been quantified. Intact egg clutches encompassing eight snail species x three developmental stages were offered to Dugesia (= Schmidtea) polychroa (Paludicola: Dugesiidae) individuals (body length = 6-12 mm) in one-on-one, no-choice 24-h feeding trials to gain a first insight on snail egg palatability to dugesiid planarias. Predatory losses were quantified as differences in planaria-present trials vs. parallel planaria-absent controls. D. polychroa predation on snail eggs was generally low. Eggs in monolayered, flat clutches of bithyniids (Bithynia leachii) and planorbids (Planorbis planorbis, Helisoma trivolvis, and Planorbarius corneus) were more susceptible to planarian predation than multilayered eggs in sausage-shaped clutches of physids (Physa acuta) and lymnaeids (Lymnaea stagnalis, Radix auricularia, and Stagnicola fuscus). Planarian predation also was higher on smaller eggs, and was not related to planarian body size. Vulnerability was also markedly species-specific, with appreciable losses recorded only for pre-hatching eggs of P. planorbis and, to a lesser extent, H. trivolvis. The results suggest that, with the possible exception for the soft-clutch, small eggs of P. planorbis, predation by D. polychroa on eggs does not impact gastropod recruitment appreciably.

1 aLombardo, Paola1 aMiccoli, Francesco, Paolo1 aGiustini, Marco1 aCicolani, Bruno uhttps://continenticola.myspecies.info/node/121700596nas a2200169 4500008004100000245012600041210006900167260001200236300000900248490000900257100002400266700001800290700001700308700003000325700001900355856005200374 2011 eng d00aFreshwater planarians (Platyhelminthes, Tricladida) from the Iberian Peninsula and Greece: diversity and notes on ecology0 aFreshwater planarians Platyhelminthes Tricladida from the Iberia c02/2011 a1-380 v27791 aVila-Farré, Miquel1 aSluys, Ronald1 aAlmagro, Ío1 aHandberg-Thorsager, Mette1 aRomero, Rafael uhttps://continenticola.myspecies.info/node/121801861nas a2200133 4500008004100000245013300041210006900174300001000243490000900253520135800262100002601620700002301646856005801669 2011 eng d00aGeoplana multicolor Graff (Platyhelminthes: Tricladida): new records and taxonomic re-interpretation of morphological characters0 aGeoplana multicolor Graff Platyhelminthes Tricladida new records a41-550 v28043 a

Many species of land flatworms have been described based on specimens, or even on a single specimen, from a sole locality. Thus, populational or individual variations are poorly known. The external morphology of Geoplana multicolor Graff, 1899 was first described based on a single specimen from the vicinities of the city of São Paulo, South Brazil. Marcus (1951) analysed specimens from São Paulo with a similar external aspect and considered them as conspecific with G. multicolor, describing their internal anatomy. In the present work, we amplify the known distribution of the species, by registering its occurrence in four localities of southern Brazil (state of Rio Grande do Sul), and comparatively analyse this relatively ample material, which includes different developmental phases. The description of histological aspects, especially those regarding musculature and secretory cells of the copulatory organs, has been enhanced and amplified after the present analysis. Thus, the description of G. multicolor is here complemented, with an improvement on the interpretation of important taxonomical characters. In addition, the paper reports, for the first time, the occurrence of an ejaculate attached to the atrial wall of a species of Geoplaninae which presents a penis papilla, and briefly discusses its significance.

1 aLeal-Zanchet, Ana, M.1 aMatos, Lisiane, B. uhttp://www.mapress.com/zootaxa/2011/f/z02804p055f.pdf01942nas a2200157 4500008004100000245017800041210006900219300001200288490000700300520131100307100002701618700002201645700001701667700001901684856008101703 2011 eng d00aLand planarians (Platyhelminthes) as a model organism for fine-scale phylogeographic studies: understanding patterns of biodiversity in the Brazilian Atlantic Forest hotspot0 aLand planarians Platyhelminthes as a model organism for finescal a887-8960 v243 a

The Brazilian Atlantic Forest is one of the richest biodiversity hotspots of the world. Paleoclimatic models have predicted two large stability regions in its northern and central parts, whereas southern regions might have suffered strong instability during Pleistocene glaciations. Molecular phylogeographic and endemism studies show, nevertheless, contradictory results: although some results validate these predictions, other data suggest that paleoclimatic models fail to predict stable rainforest areas in the south. Most studies, however, have surveyed species with relatively high dispersal rates whereas taxa with lower dispersion capabilities should be better predictors of habitat stability. Here, we have used two land planarian species as model organisms to analyse the patterns and levels of nucleotide diversity on a locality within the Southern Atlantic Forest. We find that both species harbour high levels of genetic variability without exhibiting the molecular footprint of recent colonization or population expansions, suggesting a long-term stability scenario. The results reflect, therefore, that paleoclimatic models may fail to detect refugia in the Southern Atlantic Forest, and that model organisms with low dispersal capability can improve the resolution of these models.

1 aÁlvarez-Presas, Marta1 aCarbayo, Fernando1 aRozas, Julio1 aRiutort, Marta uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2010.02220.x/abstract00626nas a2200157 4500008004100000245016800041210006900209300001400278490000700292100002400299700001800323700002000341700002000361700001900381856006800400 2011 eng d00aLand planarians (Platyhelminthes: Tricladida: Geoplanidae) from the Iberian Peninsula: new records and description of two new species, with a discussion on ecology0 aLand planarians Platyhelminthes Tricladida Geoplanidae from the  a869 - 8910 v451 aVila-Farré, Miquel1 aSluys, Ronald1 aMateos, Eduardo1 aJones, Hugh, D.1 aRomero, Rafael uhttp://pdfserve.informaworld.com/539097_788671212_935776938.pdf