@article {669, title = {The Dugesia ryukyuensis database as a molecular resource for studying switching of the reproductive system}, journal = {Zoological Science}, volume = {24}, number = {1}, year = {2007}, month = {01/2007}, pages = {31-37}, publisher = {Zoological Society of Japan}, abstract = {

The planarian Dugesia ryukyuensis reproduces both asexually and sexually, and can switch from one mode of reproduction to the other. We recently developed a method for experimentally switching reproduction of the planarian from the asexual to the sexual mode. We constructed a cDNA library from sexualized D. ryukyuensis and sequenced and analyzed 8,988 expressed sequence tags (ESTs). The ESTs were analyzed and grouped into 3,077 non-redundant sequences, leaving 1,929 singletons that formed the basis of unigene sets. Fifty-six percent of the cDNAs analyzed shared similarity (E-value\<1E -20) with sequences deposited in NCBI. Highly redundant sequences encoded granulin and actin, which are expressed in the whole body, and other redundant sequences encoded a Vasa-like protein, which is known to be a component of germ-line cells and is expressed in the ovary, and Y-protein, which is expressed in the testis. The sexualized planarian expressed sequence tag database (http://planaria.bio.keio.ac.jp/planaria/) is an open-access, online resource providing access to sequence, classification, clustering, and annotation data. This database should constitute a powerful tool for analyzing sexualization in planarians.

}, doi = {http://dx.doi.org/10.2108/zsj.24.31}, url = {http://www.bioone.org/doi/abs/10.2108/zsj.24.31}, author = {Hideyuki Ishizuka and Takanobu Maezawa and Junpei Kawauchi and Hanae Nodono and Yukako Hirao and Osamu Nishimura and Haruka Nakagawa and Kiyono Sekii and Kenta Tasaka and Hiroshi Tarui and Kiyokazu Agata and Hoshi, Motonori and Kobayashi, Kazuya and Yasubumi Sakakibara and Matsumoto, Midori} } @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} }