@article {1766, title = {Triploid planarian reproduces truly bisexually with euploid gametes produced through a different meiotic system between sex.}, journal = {Chromosoma}, volume = {123}, year = {2014}, month = {2014 Jun}, pages = {265-72}, abstract = {

Although polyploids are common among plants and some animals, polyploidization often causes reproductive failure. Triploids, in particular, are characterized by the problems of chromosomal pairing and segregation during meiosis, which may cause aneuploid gametes and results in sterility. Thus, they are generally considered to reproduce only asexually. In the case of the Platyhelminthes Dugesia ryukyuensis, populations with triploid karyotypes are normally found in nature as both fissiparous and oviparous triploids. Fissiparous triploids can also be experimentally sexualized if they are fed sexual planarians, developing both gonads and other reproductive organs. Fully sexualized worms begin reproducing by copulation rather than fission. In this study, we examined the genotypes of the offspring obtained by breeding sexualized triploids and found that the offspring inherited genes from both parents, i.e., they reproduced truly bisexually. Furthermore, meiotic chromosome behavior in triploid sexualized planarians differed significantly between male and female germ lines, in that female germ line cells remained triploid until prophase I, whereas male germ line cells appeared to become diploid before entry into meiosis. Oocytes at the late diplotene stage contained not only paired bivalents but also unpaired univalents that were suggested to produce diploid eggs if they remained in subsequent processes. Triploid planarians may therefore form euploid gametes by different meiotic systems in female and male germ lines and thus are be able to reproduce sexually in contrast to many other triploid organisms.

}, keywords = {Animals, Chromosomes, Female, Germ Cells, Male, Meiosis, planarians, reproduction, Triploidy}, issn = {1432-0886}, doi = {10.1007/s00412-013-0449-2}, author = {Chinone, Ayako and Nodono, Hanae and Matsumoto, Midori} } @article {1723, title = {Predator effects on a detritus-based food web are primarily mediated by non-trophic interactions}, journal = {J Anim Ecol}, volume = {83}, year = {2014}, month = {2014 Jul}, pages = {953-62}, abstract = {

Predator effects on ecosystems can extend far beyond their prey and are often not solely lethally transmitted. Change in prey traits in response to predation risk can have important repercussions on community assembly and key ecosystem processes (i.e. trait-mediated indirect effects). In addition, some predators themselves alter habitat structure or nutrient cycling through ecological engineering effects. Tracking these non-trophic pathways is thus an important, yet challenging task to gain a better grasp of the functional role of predators. Multiple lines of evidence suggest that, in detritus-based food webs, non-trophic interactions may prevail over purely trophic interactions in determining predator effects on plant litter decomposition. This hypothesis was tested in a headwater stream by modulating the density of a flatworm predator (Polycelis felina) in enclosures containing oak (Quercus robur) leaf litter exposed to natural colonization by small invertebrates and microbial decomposers. Causal path modelling was used to infer how predator effects propagated through the food web. Flatworms accelerated litter decomposition through positive effects on microbial decomposers. The biomass of prey and non-prey invertebrates was not negatively affected by flatworms, suggesting that net predator effect on litter decomposition was primarily determined by non-trophic interactions. Flatworms enhanced the deposition and retention of fine sediments on leaf surface, thereby improving leaf colonization by invertebrates - most of which having strong affinities with interstitial habitats. This predator-induced improvement of habitat availability was attributed to the sticky nature of the mucus that flatworms secrete in copious amount while foraging. Results of path analyses further indicated that this bottom-up ecological engineering effect was as powerful as the top-down effect on invertebrate prey. Our findings suggest that predators have the potential to affect substantially carbon flow and nutrient cycling in detritus-based ecosystems and that this impact cannot be fully appreciated without considering non-trophic effects.

}, keywords = {Animals, Biomass, Carbon Cycle, Food Chain, Geologic Sediments, Models, Biological, planarians, Plant Leaves, Predatory Behavior, Quercus, Rivers}, issn = {1365-2656}, doi = {10.1111/1365-2656.12189}, author = {Majdi, Nabil and Boich{\'e}, Anatole and Traunspurger, Walter and Lecerf, Antoine} } @article {1703, title = {Genes for regeneration}, journal = {eLife}, volume = {3}, year = {2014}, month = {2014/04/15}, pages = {e02517}, publisher = {eLife Sciences Publications, Ltd}, abstract = {FoxA, an evolutionarily conserved gene involved in the development of the digestive system in many animals, has an important role in regeneration in flatworms.}, keywords = {Pharynx, planaria, regeneration, single-organ regeneration, stem cell}, isbn = {2050-084X}, url = {https://dx.doi.org/10.7554/eLife.02517}, author = {Rossant, Janet} } @article {1696, title = {Confirmation and Distribution of Tetrodotoxin for the First Time in Terrestrial Invertebrates: Two Terrestrial Flatworm Species (Bipalium adventitium and Bipalium kewense)}, journal = {PLoS ONE}, volume = {9}, year = {2014}, month = {2014}, pages = {e100718}, publisher = {Public Library of Science}, address = {San Francisco, USA}, abstract = {

The potent neurotoxin tetrodotoxin (TTX) is known from a diverse array of taxa, but is unknown in terrestrial invertebrates. Tetrodotoxin is a low molecular weight compound that acts by blocking voltage-gated sodium channels, inducing paralysis. However, the origins and ecological functions of TTX in most taxa remain mysterious. Here, we show that TTX is present in two species of terrestrial flatworm (Bipalium adventitium and Bipalium kewense) using a competitive inhibition enzymatic immunoassay to quantify the toxin and high phase liquid chromatography to confirm the presence. We also investigated the distribution of TTX throughout the bodies of the flatworms and provide evidence suggesting that TTX is used during predation to subdue large prey items. We also show that the egg capsules of B. adventitium have TTX, indicating a further role in defense. These data suggest a potential route for TTX bioaccumulation in terrestrial systems.

}, isbn = {1932-6203}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4070999/}, author = {Stokes, Amber N and Ducey, Peter K and Neuman-Lee, Lorin and Hanifin, Charles T and French, Susannah S and Pfrender, Michael E and Brodie, Edmund D and Brodie Jr, Edmund D}, editor = {Dickens, Joseph Clifton} } @article {1643, title = {Fluorescent sperm in a transparent worm: validation of a GFP marker to study sexual selection}, volume = {14}, year = {2014}, month = {2014//}, url = {http://dx.doi.org/10.1186/1471-2148-14-148}, author = {Marie-Orleach, L. and Janicke, T. and Vizoso, D. B. and Eichmann, M. and Scharer, L.} } @article {1647, title = {The centrosome duplication cycle in health and disease}, volume = {588}, year = {2014}, month = {2014//}, url = {http://dx.doi.org/10.1016/j.febslet.2014.06.030}, author = {Nigg, E. A. and Cajanek, L. and Arquint, C.} } @article {1624, title = {Centriole amplification by mother and daughter centrioles differs in multiciliated cells}, volume = {516}, year = {2014}, month = {2014//}, author = {Al Jord, A. and Lemaitre, A. I. and Delgehyr, N. and Faucourt, M. and Spassky, N. and Meunier, A.} } @article {1630, title = {Multiciliated cells}, volume = {24}, year = {2014}, month = {2014//}, url = {http://dx.doi.org/10.1016/j.cub.2014.08.047}, author = {Brooks, E. R. and Wallingford, J. B.} } @article {1642, title = {Multicilin drives centriole biogenesis via E2f proteins}, volume = {28}, year = {2014}, month = {2014//}, url = {http://dx.doi.org/10.1101/gad.243832.114}, author = {Ma, L. and Quigley, I. and Omran, H. and Kintner, C.} } @article {1617, title = {Selective amputation of the pharynx identifies a FoxA-dependent regeneration program in planaria}, volume = {3}, year = {2014}, month = {2014//}, author = {Adler, C. E. and Seidel, C. W. and McKinney, S. A. and Alvarado, A. S.} } @article {1602, title = {edgeR for differential RNA-seq and ChIP-seq analysis: an application to stem cell biology}, volume = {1150}, year = {2014}, month = {2014//}, url = {http://dx.doi.org/10.1007/978-1-4939-0512-6_3}, author = {Nikolayeva, O. and Robinson, M. D.} } @article {1588, title = {Single-cell analysis reveals functionally distinct classes within the planarian stem cell compartment}, volume = {15}, year = {2014}, month = {2014//}, url = {http://dx.doi.org/10.1016/j.stem.2014.06.007}, author = {Wolfswinkel, J. C. and Wagner, D. E. and Reddien, P. W.} } @article {1495, title = {Investigation of the ultrastructure of Dendrocoelum constrictum (Platyhelminthes, Tricladida) spermatogenesis and mature spermatozoa}, volume = {337}, year = {2014}, month = {2014/9//}, pages = {513 - 520}, abstract = {

To add to our understanding of dendrocoelid spermatozoa and to describe additional phylogenetic characters, the ultrastructure of the testis was investigated in the subterranean freshwater planarian Dendrocoelum constrictum. This is the first study investigating spermatogenesis and spermatozoon ultrastructure in a subterranean freshwater planarian species. We found that the basic structure of spermatozoa in D.\ constrictum is similar to that of other Tricladida that have been studied previously. In fact, D.\ constrictum spermatozoa possess an elongated nucleus, one giant mitochondrion, and two subterminal flagella with a 9 + \‘1\’ pattern. The flagella emerge together from one side of the spermatozoon. However, D.\ constrictum has some characteristics that have not yet been described for other freshwater planarians. In fact, the number of cortical microtubules reaches the maximum number in the anterior and middle part of region I, and then decrease until they disappear towards the posterior extremity of the spermatozoon. The extreme tip of the anterior region of the spermatozoon exhibits a specific external ornamentation of the plasma membrane.

}, keywords = {Dendrocoelum constrictum, Free-living flatworm, Mature spermatozoon, Spermatogenesis, Ultrastructure}, isbn = {1631-0691}, url = {http://www.sciencedirect.com/science/article/pii/S1631069114001632}, author = {Harrath, Abdel Halim and Gammoudi, Mehrez and Mansour, Lamjed and Ahmed, Mukhtar and Sirotkin, Alexander V. and Al Omar, Suliman Y. and Ibrahim, Khalid E. and Alwasel, Saleh H.} } @article {774, title = {Diversity of introduced terrestrial flatworms in the Iberian Peninsula: a cautionary tale}, journal = {PeerJ}, volume = {2}, year = {2014}, month = {06/2014}, chapter = {e430}, doi = {http://dx.doi.org/10.7717/peerj.430}, author = {Marta {\'A}lvarez-Presas and Mateos, Eduardo and {\`A}ngels Tud{\'o} and Hugh D. Jones and Marta Riutort} } @article {729, title = {DrRad51 is required for chiasmata formation in meiosis in planarian Dugesia ryukyuensis}, journal = {Molecular Reproduction and Development}, year = {2014}, abstract = {

Rad51, a conserved eukaryotic protein, mediates the homologous-recombination repair of DNA double-strand breaks that occur during both mitosis and meiosis. During prophase I of meiosis, homologous recombination enhances the linkage between homologous chromosomes to increase the accuracy of segregation at anaphase I. In polyploidy situtations, however, difficulties with homologous chromosome segregation often disrupt meiosis. Yet, triploid individuals of the planarian Dugesia ryukyuensis are able to produce functional gametes through a specialized form of meiosis. To shed light on the molecular mechanisms that promote successful meiosis in triploid D. ryukyuensis, we investigated rad51 gene function. We isolated three genes of the Rad51 family, the Rad51 homolog Dr-rad51 and the Rad51 paralogs Dr-rad51B and Dr-rad51C. Dr-rad51 was expressed in germ-line and presumably in somatic stem cells, but was not necessary for the regeneration of somatic tissue. RNA-interference (RNAi) depletion of Dr-rad51 during sexualization did not affect chromosome behavior in zygotene oocytes, but did result in the loss of chiasmata at the diplotene stage. Thus, homologous recombination does not appear to be necessary for synapsis, but is needed for crossover and proper segregation in D. ryukyuensis.

}, doi = {10.1002/mrd.22308}, author = {Ayako Chinone and Matsumoto, Midori} } @article {768, title = {Insights into the origin and distribution of biodiversity in the Brazilian Atlantic forest hot spot: a statistical phylogeographic study using a low-dispersal organism}, journal = {Heredity}, year = {2014}, pages = {1-10}, doi = {10.1038/hdy.2014.3.}, author = {Marta {\'A}lvarez-Presas and S{\'a}nchez-Gracia, A. and Carbayo, F. and Rozas, J. and M Riutort} } @article {739, title = {The invasive New Guinea flatworm Platydemus manokwari in France, the first record for Europe: time for action is now}, journal = {PeerJ}, volume = {2}, year = {2014}, pages = {e297}, abstract = {

Non-indigenous terrestrial flatworms (Platyhelminthes) have been recorded in thirteen European countries. They include Bipalium kewense and Dolichoplana striata that are largely restricted to hothouses and may be regarded as non-invasive species. In addition there are species from the southern hemisphere such as the invasive New Zealand flatworm Arthurdendyus triangulatus in the United Kingdom, Eire and the Faroe Islands, the Australian flatworm Australoplana sanguinea alba in Eire and the United Kingdom, and the Australian Blue Garden flatworm Caenoplana coerulea in France, Menorca and the United Kingdom. The United Kingdom has some twelve or more non-indigenous species most of which are Australian and New Zealand species. These species may move to an invasive stage when optimum environmental and other conditions occur, and the flatworms then have the potential to cause economic or environmental harm. In this paper, we report the identification (from morphology and molecular analysis of COI sequences) of non-indigenous terrestrial flatworms found in a hothouse in Caen (France) as the New Guinea flatworm Platydemus manokwari de Beauchamp, 1963 (Platyhelminthes, Continenticola, Geoplanidae, Rhynchodeminae). Platydemus manokwari is among the \“100 World\’s Worst Invader Alien Species\”. Lists of World geographic records, prey in the field and prey in laboratories of P. manokwari are provided. This species is considered a threat to native snails wherever it is introduced. The recent discovery of P. manokwari in France represents a significant extension of distribution of this Invasive Alien Species from the Indo-Pacific region to Europe. If it escaped the hothouse, the flatworm might survive winters and become established in temperate countries. The existence of this species in France requires an early warning of this incursion to State and European Union authorities, followed by the eradication of the flatworm in its locality, tightening of internal quarantine measures to prevent further spread of the flatworm to and from this site, identifying if possible the likely primary source of the flatworm, and tracing other possible incursions that may have resulted from accidental dispersal of plants and soil from the site.

}, doi = {10.7717/peerj.297}, url = {https://peerj.com/articles/297.pdf}, author = {Jean-Lou Justine​ and Leigh Winsor and Delphine Gey and Pierre Gros and Jessica Th{\'e}venot} } @article {857, title = {A new and aberrant species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Madagascar}, journal = {ZooKeys}, volume = {425}, year = {2014}, pages = {71-88}, author = {Giacinta Angela Stocchino and Ronald Sluys and Manconi, Renata} } @article {775, title = {A new species of land flatworm (Platyhelminthes: Continenticola) from areas of Araucaria Forest in southern Brazil}, journal = {Zootaxa}, volume = {3794}, number = {4}, year = {2014}, pages = {514-524}, author = {ILANA ROSSI and Marcela Fontoura and Silvana Amaral and Leal-Zanchet, Ana Maria} } @article {727, title = {Planarian D-amino acid oxidase is involved in ovarian development during sexual induction}, journal = {Mechanisms of Development}, year = {2014}, url = {http://www.sciencedirect.com/science/article/pii/S0925477314000033}, author = {Takanobu Maezawa and Hiroyuki Tanaka and Haruka Nakagawa and Mizuki Ono and Manabu Aoki and Matsumoto, Midori and Tetsuo Ishida and Kihachiro Horiike and Kobayashi, Kazuya} }