TY - JOUR
T1 - Drpiwi-1 is essential for germline cell formation during sexualization of the planarian Dugesia ryukyuensis
AU - Nakagawa, Haruka
AU - Ishizu, Hirotsugu
AU - Hasegawa, Reiko
AU - Kobayashi, Kazuya
AU - Matsumoto, Midori
N1 - Funding Information:
We thank Dr. Sachiko Ishida at Hirosaki University for her gift of the OH strain; Dr. Phil Newmark and members of his laboratory at the University of Illinois for providing the pDONRdT7 and E. coli strain HT115 and for technical advice for the RNAi feeding; Dr. Haruhiko Siomi and Dr. Mikiko C. Siomi at the School of Medicine, Keio University, for technical advice in the preparation of the anti-DrPiwi-1 monoclonal antibody; and Hidefumi Orii at University of Hyogo for technical advice on immunohistochemistry and for discussion. This work was supported in part by grants from the Ministry of Education, Culture, Sports, Science, and Technology to MM ( 16086209 ) and Keio Leading-edge Laboratory of Science & Technology Research Grant for Ph.D. Program to HN.
PY - 2012/1/1
Y1 - 2012/1/1
N2 - A piwi homolog is required for the regulation of stem cells, formation and maintenance of germline stem cells, and gametogenesis in many metazoans. Planarians can change their reproductive mode seasonally, both asexually and sexually, and develop and maintain germ cells and sexual organs. They have many pluripotent stem cells (neoblasts) that can differentiate into both somatic and germline stem cells. Thus, we searched for a piwi subfamily in the planarian Dugesia ryukyuensis. Four piwi homologs, identified as Drpiwi-1, -2, -3, and -4, were expressed in sexually reproductive worms. We then selectively destroyed the neoblasts by irradiating the worms with X-rays. In such worms, Drpiwi-1, -2, and -3 were not expressed at all, whereas Drpiwi-4 was expressed to the same degree as that in non-irradiated controls, indicating that Drpiwi-1, -2, and -3, but not Drpiwi-4, are expressed in neoblasts. During the regeneration process, Drpiwi-2(RNAi) and -3(RNAi) worms failed to regenerate after ablation, but Drpiwi-1 and -4(RNAi) worms regenerated. During the sexualizing process, Drpiwi-1(RNAi) worms failed to develop ovaries and testes, but somatic sexual organs were unaffected. Germ cell development was normal in Drpiwi-4(RNAi) worms. Therefore, Drpiwi-2 and -3 may be related to the regulation of neoblasts important for maintaining homeostasis, and Drpiwi-1 is essential for the development of germ cells but not somatic sexual organs. DrPiwi-1 is localized in the cytoplasm of stem cells and germline cells and may be involved in regulating some gene expression. We suggest that planarian Piwi controls germline formation via RNA silencing mechanisms.
AB - A piwi homolog is required for the regulation of stem cells, formation and maintenance of germline stem cells, and gametogenesis in many metazoans. Planarians can change their reproductive mode seasonally, both asexually and sexually, and develop and maintain germ cells and sexual organs. They have many pluripotent stem cells (neoblasts) that can differentiate into both somatic and germline stem cells. Thus, we searched for a piwi subfamily in the planarian Dugesia ryukyuensis. Four piwi homologs, identified as Drpiwi-1, -2, -3, and -4, were expressed in sexually reproductive worms. We then selectively destroyed the neoblasts by irradiating the worms with X-rays. In such worms, Drpiwi-1, -2, and -3 were not expressed at all, whereas Drpiwi-4 was expressed to the same degree as that in non-irradiated controls, indicating that Drpiwi-1, -2, and -3, but not Drpiwi-4, are expressed in neoblasts. During the regeneration process, Drpiwi-2(RNAi) and -3(RNAi) worms failed to regenerate after ablation, but Drpiwi-1 and -4(RNAi) worms regenerated. During the sexualizing process, Drpiwi-1(RNAi) worms failed to develop ovaries and testes, but somatic sexual organs were unaffected. Germ cell development was normal in Drpiwi-4(RNAi) worms. Therefore, Drpiwi-2 and -3 may be related to the regulation of neoblasts important for maintaining homeostasis, and Drpiwi-1 is essential for the development of germ cells but not somatic sexual organs. DrPiwi-1 is localized in the cytoplasm of stem cells and germline cells and may be involved in regulating some gene expression. We suggest that planarian Piwi controls germline formation via RNA silencing mechanisms.
KW - Germline cell formation
KW - Piwi
KW - Planarians
KW - Stem cell regulation
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U2 - 10.1016/j.ydbio.2011.10.014
DO - 10.1016/j.ydbio.2011.10.014
M3 - Article
C2 - 22024321
AN - SCOPUS:83055186510
VL - 361
SP - 167
EP - 176
JO - Developmental Biology
JF - Developmental Biology
SN - 0012-1606
IS - 1
ER -