@article {1675, title = {Identification and characterization of a novel multifunctional placenta specific protein 8 in Dugesia japonica}, volume = {613}, year = {2017}, month = {2017/5/20/}, pages = {1 - 9}, abstract = {

AbstractPlacenta specific protein 8 (Plac8) has been well studied in vertebrates, yet little is known in invertebrates. In this study, a novel Plac8 from the planarian Dugesia japonica was identified and its functions in immune responses and development were characterized. Our results show that Djplac8 was expressed in the pharynx, epidermis and intestine of intact adult planarian. The expression of DjPlac8 increased significantly upon lipopolysaccharide (LPS) challenge, and inhibited the growth of the Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), suggesting the role of Plac8 in immune response. Spatial and temporal expression and distribution of DjPlac8 mRNA in regenerated planarians indicates that DjPlac8 was mainly expressed in the pharynx. In situ hybridization also revealed the elevated expression of the DjPlac8 gene in the embryonic pharynx, germ band and parenchyma cells, indicating an important role in embryonic development of D. japonica. When DjPlac8 was deactivated by RNA interference-mediated knockdown, the head of planarians underwent abnormal development. In summary, we identified DjPlac8 as a novel multifunctional protein that plays essential roles in immune response and development of planarians.

}, keywords = {Development, Immunity, Pharynx, Plac8, planarian}, isbn = {0378-1119}, url = {http://www.sciencedirect.com/science/article/pii/S0378111917301130}, author = {Pang, Qiuxiang and Gao, Lili and Bai, Yun and Deng, Hongkuan and Han, Yu and Hu, Wenjing and Zhang, Yanhui and Yuan, Shanhang and Sun, Wenping and Lu, Yiqian and Zhang, Xiufang and Liu, Baohua and Zhao, Bosheng} } @article {1546, title = {De Novo Transcriptome Analysis Provides Insights into Immune Related Genes and the RIG-I-Like Receptor Signaling Pathway in the Freshwater Planarian (Dugesia japonica)}, journal = {PLoS ONE}, volume = {11}, year = {2016}, month = {2016}, pages = {e0151597}, publisher = {Public Library of Science}, address = {San Francisco, CA USA}, abstract = {BACKGROUND: The freshwater planarian Dugesia japonica (D. japonica) possesses extraordinary ability to regenerate lost organs or body parts. Interestingly, in the process of regeneration, there is little wound infection, suggesting that D. japonica has a formidable innate immune system. The importance of immune system prompted us to search for immune-related genes and RIG-I-like receptor signaling pathways. RESULTS: Transcriptome sequencing of D. japonica was performed on an IlluminaHiSeq2000 platform. A total of 27,180 transcripts were obtained by Trinity assembler. CEGMA analysis and mapping of all trimmed reads back to the assembly result showed that our transcriptome assembly covered most of the whole transcriptome. 23,888 out of 27,180 transcripts contained ORF (open reading fragment), and were highly similar to those in Schistosoma mansoni using BLASTX analysis. 8,079 transcripts (29.7\%) and 8,668 (31.9\%) were annotated by Blast2GO and KEGG respectively. A DYNLRB-like gene was cloned to verify its roles in the immune response. Finally, the expression patterns of 4 genes (RIG-I, TRAF3, TRAF6, P38) in the RIG-I-like receptor signaling pathway were detected, and the results showed they are very likely to be involved in planarian immune response. CONCLUSION: RNA-Seq analysis based on the next-generation sequencing technology was an efficient approach to discover critical genes and to understand their corresponding biological functions. Through GO and KEGG analysis, several critical and conserved signaling pathways and genes related to RIG-I-like receptor signaling pathway were identified. Four candidate genes were selected to identify their expression dynamics in the process of pathogen stimulation. These annotated transcripts of D. japonica provide a useful resource for subsequent investigation of other important pathways.}, isbn = {1932-6203}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4795655/}, author = {Pang, Qiuxiang and Gao, Lili and Hu, Wenjing and An, Yang and Deng, Hongkuan and Zhang, Yichao and Sun, Xiaowen and Zhu, Guangzhong and Liu, Baohua and Zhao, Bosheng}, editor = {Robinson-Rechavi, Marc} } @article {1538, title = {Unusually Large Number of Mutations in Asexually Reproducing Clonal Planarian Dugesia japonica}, journal = {PLoS ONE}, volume = {10}, year = {2015}, month = {2015}, pages = {e0143525}, publisher = {Public Library of Science}, address = {San Francisco, CA USA}, abstract = {

We established a laboratory clonal strain of freshwater planarian (Dugesia japonica) that was derived from a single individual and that continued to undergo autotomous asexual reproduction for more than 20 years, and we performed large-scale genome sequencing and transcriptome analysis on it. Despite the fact that a completely clonal strain of the planarian was used, an unusually large number of mutations were detected. To enable quantitative genetic analysis of such a unique organism, we developed a new model called the Reference Gene Model, and used it to conduct large-scale transcriptome analysis. The results revealed large numbers of mutations not only outside but also inside gene-coding regions. Non-synonymous SNPs were detected in 74\% of the genes for which valid ORFs were predicted. Interestingly, the high-mutation genes, such as metabolism- and defense-related genes, were correlated with genes that were previously identified as diverse genes among different planarian species. Although a large number of amino acid substitutions were apparently accumulated during asexual reproduction over this long period of time, the planarian maintained normal body-shape, behaviors, and physiological functions. The results of the present study reveal a unique aspect of asexual reproduction.

}, isbn = {1932-6203}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4654569/}, author = {Nishimura, Osamu and Hosoda, Kazutaka and Kawaguchi, Eri and Yazawa, Shigenobu and Hayashi, Tetsutaro and Inoue, Takeshi and Umesono, Yoshihiko and Agata, Kiyokazu}, editor = {Fu, Binying} } @article {1520, title = {Comprehensive gene expression analyses in pluripotent stem cells of a planarian, Dugesia japonica}, volume = {56}, year = {2012}, month = {2012//}, url = {http://dx.doi.org/10.1387/ijdb.113434ns}, author = {Shibata, N. and Hayashi, T. and Fukumura, R. and Fujii, J. and Kudome-Takamatsu, T. and Nishimura, O.} } @article {1493, title = {Evolutionary Analysis of Mitogenomes from Parasitic and Free-Living Flatworms}, journal = {PLoS ONE}, volume = {10}, year = {2015}, month = {2015}, pages = {e0120081}, publisher = {Public Library of Science}, address = {San Francisco, CA USA}, abstract = {

Mitochondrial genomes (mitogenomes) are useful and relatively accessible sources of molecular data to explore and understand the evolutionary history and relationships of eukaryotic organisms across diverse taxonomic levels. The availability of complete mitogenomes from Platyhelminthes is limited; of the 40 or so published most are from parasitic flatworms (Neodermata). Here, we present the mitogenomes of two free-living flatworms (Tricladida): the complete genome of the freshwater species Crenobia alpina (Planariidae) and a nearly complete genome of the land planarian Obama sp. (Geoplanidae). Moreover, we have reanotated the published mitogenome of the species Dugesia japonica (Dugesiidae). This contribution almost doubles the total number of mtDNAs published for Tricladida, a species-rich group including model organisms and economically important invasive species. We took the opportunity to conduct comparative mitogenomic analyses between available free-living and selected parasitic flatworms in order to gain insights into the putative effect of life cycle on nucleotide composition through mutation and natural selection. Unexpectedly, we did not find any molecular hallmark of a selective relaxation in mitogenomes of parasitic flatworms; on the contrary, three out of the four studied free-living triclad mitogenomes exhibit higher A+T content and selective relaxation levels. Additionally, we provide new and valuable molecular data to develop markers for future phylogenetic studies on planariids and geoplanids.

}, isbn = {1932-6203}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4368550/}, author = {Sol{\`a}, Eduard and {\'A}lvarez-Presas, Marta and Fr{\'\i}as-L{\'o}pez, Cristina and Littlewood, D Timothy J and Rozas, Julio and Riutort, Marta}, editor = {Escriva, Hector} } @article {385, title = {A new freshwater planarian, Dugesia japonica, commonly but erroneously known as Dugesia gonocephala (Duges)}, journal = {Annotationes zoologicae Japonenses}, volume = {37}, number = {3}, year = {1964}, pages = {185-194}, publisher = {The Zoological Society of Japan}, author = {Ichikawa, A. and Masaharu Kawakatsu} } @article {755, title = {Report on the ecological survey of freshwater planarians in Kyoto city and its adjacent district, Honshu}, journal = {Japanese Journal of Ecology}, volume = {17}, number = {3}, year = {1967}, pages = {112-118}, abstract = {

In the vicinity of Kyoto City, 4 species of freshwater planarians, Dugesia japonica, Phagocata vivida, Phagocata kawakatsui and Bdellocephala brunnea, were found. D. japonica was most common in the stations both in the plain and the mountainous districts (below the altitude of about 950 m). P. vivida was rather common in the cold-water stations within the altitude range from about 120 to 950 m or more. P. kawakatsui was found only in a spring-fed stream in Kameoka City (Asahi-cho; the type locality of this species) and in a shallow well at Saga-tenryuji-chd in Kyoto City. A small population of B. brunnea was found in a large spring-fed stream at Nishioji-sichijo in Kyoto City (the southernmost locality of this species). This station is well known to biologists as the locality of the sexual race of D. japonica (the Nishioji stock). The type of the vertical distribution in the area surveyed is shown as J-JV-V (J; D japonica; V: P vivida). The 2 species of true lake-dwelling tri-clads, BdellocepEala annandalci and Dendrocoelopsis? sp. of Lake Biwa-ko, were recorded from the muddy bottom (35 to 50 m or more in depth) of the middle and northern parts of Lake Biwa-ko.

}, author = {Masaharu Kawakatsu and Ogawara, Genchu and Tarui, Yoshitsugu} } @article {386, title = {Results of the speleological survey in South Korea 1966 VI. Freshwater planarians from limestone caves of South Korea}, journal = {Bulletin of the National Science Museum, Tokyo}, volume = {10}, year = {1967}, pages = {247-258}, author = {Masaharu Kawakatsu and Kim, W-J} } @article {757, title = {Morphological studies on the freshwater planarian, Dugesia japonica Ichikawa et Kawakatsu from Korea}, journal = {Zoological Magazine (Dobutsugaku Zasshi)}, volume = {75}, year = {1966}, pages = {103-107}, author = {Masaharu Kawakatsu and Kim, W. J.} } @article {670, title = {Effect of different fixatives on a common japanese freshwater planarian Dugesia japonica Ichikawa et Kawakatsu}, journal = {The Bulletin of Fuji Women{\textquoteright}s College}, volume = {10}, year = {1972}, pages = {81-117}, author = {Masaharu Kawakatsu and Takeshi Miyazaki} } @article {368, title = {Freshwater triclads (Turbellaria, Tricladida) from the oriental region}, journal = {Zoological Journal of the Linnean Society}, volume = {49}, year = {1970}, month = {11/1970}, pages = {271-294}, abstract = {

Two new freshwater triclad species of the genus Dugesia Girard, 1850 are described from the oriental region. The first is the only species of freshwater triclad described from Ceylon and the second, a cavernicolous form, is the only one known from Malaya. A synopsis, in tabular form, of the oriental Dugesia species is also given and some aspects of their distribution are discussed. It is intended that the tabular synopsis should provide diagnostic characters for the delimitation of the new and previously described species, and act as a basis for a future revision of the oriental representatives of the genus, many of which are poorly described or poorly known. Apreliminary dichotomous key to the valid species is also provided.

}, doi = {10.1111/j.1096-3642.1970.tb00742.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1096-3642.1970.tb00742.x/abstract}, author = {Ian R. Ball} } @inbook {790, title = {Planarian Regeneration}, year = {1969}, pages = {viii+276, 20 plates}, publisher = {Pergamon Press}, organization = {Pergamon Press}, address = {Oxford; New York}, issn = {0080128769}, author = {Br{\o}ndsted, Holger Valdemar} } @article {759, title = {The fresh water planaria from Hong-Kong}, journal = {Annotationes Zoologicae Japonenses}, volume = {48}, number = {4}, year = {1975}, pages = {262-273}, abstract = {

The occurrence in Hong Kong of a freshwater planarian species Dugesia japonica Ichikawa et Kawakatsu, 1964, is reported. A taxonomic revision of every known record of Dugesia in China is also given. Stimpson\’s (1857) 3 uncertain species established from Hong Kong and the E China Sea area (Planaria sinensis, P. cinerea and P. badia) seem to be identical with D. japonica, the commonest and polymorphic form distributed widely in the NE area of the Far East including the Japanese Islands. It is suggested that it would be better to suppress the names of Stimpson\’s species as nomina oblita than to rename the now well-established D. japonica.

}, issn = {0003-5092}, author = {Masaharu Kawakatsu and Wong, M. H.} } @inbook {470, title = {A contribution to the phylogeny and biogeography of the freshwater triclads (Platyhelminthes, Turbellaria)}, booktitle = {Biology of the Turbellaria}, year = {1974}, pages = {339-401}, publisher = {McGraw-Hill}, organization = {McGraw-Hill}, address = {New York}, author = {Ian R. Ball} } @article {springerlink:10.1007/BF00036366, title = {A review of chromosomal variation in Dugesia japonica and D. ryukyuensis in the Far East}, journal = {Hydrobiologia}, volume = {305}, year = {1995}, note = {10.1007/BF00036366}, pages = {79-84}, publisher = {Springer Netherlands}, abstract = {{The chromosome numbers of Dugesia japonica Ichikawa et Kawakatsu, 1964, are n = 8}}, issn = {0018-8158}, url = {http://dx.doi.org/10.1007/BF00036366}, author = {Tamura, Sachiko and Oki, Iwashiro and Masaharu Kawakatsu} } @article {springerlink:10.1007/BF00036363, title = {Taxonomy and geographical distribution of Dugesia japonica and D. ryukyuensis in the Far East}, journal = {Hydrobiologia}, volume = {305}, year = {1995}, note = {10.1007/BF00036363}, pages = {55-61}, publisher = {Springer Netherlands}, abstract = {

{Dugesia japonica Ichikawa et Kawakatsu, 1964, is a common and polymorphic species of freshwater planarian distributed widely in the Far East. In 1976 the geographic populations were separated into 2 subspecies (D.j.japonica and D.j. ryukyuensis). The taxonomy of this species is reconsidered once again from the morphological, anatomical, histological, and karyological viewpoints. From the result of these studies, D.j. ryukyuensis is elevated to the rank of species: D. ryukyuensis Kawakatsu, 1976. D. japonica (n = 8}

}, issn = {0018-8158}, url = {http://dx.doi.org/10.1007/BF00036363}, author = {Masaharu Kawakatsu and Oki, Iwashiro and Tamura, Sachiko} } @article {14, title = {The genus Dugesia in Australia, with its phylogenetic analysis and historical biogeography (Platyhelminthes, Tricladida, Dugesiidae)}, journal = {Zoologica Scripta}, volume = {27}, year = {1998}, pages = {273-289}, chapter = {273}, abstract = {

The new species Dugesia notogaea Sluys \& Kawakatsu, sp. n. is described from Queensland, Australia, representing the first record of the genus Dugesia for that continent. A phylogenetic analysis of the 68 species of Dugesia resulted in the discovery of a new apomorphy for the genus, and a cladogram showing two major phyletic groups. The distributional range of one group has a western accent, whereas that of the other group has an eastern emphasis; the ranges of these two groups overlap in Africa and the Mediterranean region. We attempt to determine the ancestral area for both the Dugesiidae and Dugesia. A scenario for the historical biogeography of the genus Dugesia is discussed. In this scenario it is presumed that the geological history of the Australasian region enabled Dugesia\’s from southeast Asia to colonize northern Australia.

}, doi = {10.1111/j.1463-6409.1998.tb00461.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1463-6409.1998.tb00461.x/abstract}, author = {Ronald Sluys and Masaharu Kawakatsu and Leigh Winsor} } @article {482, title = {The Complete Mitochondrial Genome of Dugesia japonica (Platyhelminthes; Order Tricladida)}, journal = {Zoological Science}, volume = {29}, number = {10}, year = {2012}, month = {10/2012}, pages = {672-680}, publisher = {Zoological Society of Japan}, chapter = {672}, abstract = {

We used two sequencing methods, namely long polymerase chain reaction (PCR) and primer walking, to determine the complete mitochondrial DNA (mtDNA) sequence of Dugesia japonica and most of the mtDNA sequence of Dugesia ryukyuensis. The genome of D. japonica contained 36 genes including 12 of the 13 protein-coding genes characteristic of metazoan mitochondrial genomes, two ribosomal RNA genes, and 22 transfer RNA genes. The genome of D. ryukyuensis contained 33 genes, including 12 protein-coding genes, two ribosomal RNA genes, and 19 transfer RNA genes. The gene order of the mitochondrial genome from the Dugesia species showed no clear homology with either the Neodermata or other free-living Rhabditophora. This indicates that the platyhelminths exhibit great variability in mitochondrial gene order. This is the first complete sequence analysis of the mitochondrial genome of a free-living member of Rhabditophora, which will facilitate further studies on the population genetics and genomic evolution of the Platyhelminthes.

}, doi = {http://dx.doi.org/10.2108/zsj.29.672}, url = {http://www.bioone.org/doi/full/10.2108/zsj.29.672}, author = {Masato Sakai and Mitsuru Sakaizumi} } @article {481, title = {Comparative transcriptome analysis between planarian Dugesia japonica and other platyhelminth species}, journal = {BMC Genomics}, volume = {13}, year = {2012}, month = {06/2012}, chapter = {289}, abstract = {

Background Planarians are considered to be among the extant animals close to one of the earliest groups of organisms that acquired a central nervous system (CNS) during evolution. Planarians have a bilobed brain with nine lateral branches from which a variety of external signals are projected into different portions of the main lobes. Various interneurons process different signals to regulate behavior and learning/memory. Furthermore, planarians have robust regenerative ability and are attracting attention as a new model organism for the study of regeneration. Here we conducted large-scale EST analysis of the head region of the planarian Dugesia japonica to construct a database of the head-region transcriptome, and then performed comparative analyses among related species. Results A total of 54,752 high-quality EST reads were obtained from a head library of the planarian Dugesia japonica, and 13,167 unigene sequences were produced by de novo assembly. A new method devised here revealed that proteins related to metabolism and defense mechanisms have high flexibility of amino-acid substitutions within the planarian family. Eight-two CNS-development genes were found in the planarian (cf. C. elegans 3; chicken 129). Comparative analysis revealed that 91\% of the planarian CNS-development genes could be mapped onto the schistosome genome, but one-third of these shared genes were not expressed in the schistosome. Conclusions We constructed a database that is a useful resource for comparative planarian transcriptome studies. Analysis comparing homologous genes between two planarian species showed that the potential of genes is important for accumulation of amino-acid substitutions. The presence of many CNS-development genes in our database supports the notion that the planarian has a fundamental brain with regard to evolution and development at not only the morphological/functional, but also the genomic, level. In addition, our results indicate that the planarian CNS-development genes already existed before the divergence of planarians and schistosomes from their common ancestor.

}, doi = {10.1186/1471-2164-13-289}, url = {http://www.biomedcentral.com/1471-2164/13/289}, author = {Osamu Nishimura and Yukako Hirao and Hiroshi Tarui and Kiyokazu Agata} }