1
|
Kim IV, Demtröder T, Kuhn CD. Isolation and Library Preparation of Planarian piRNAs. Methods Mol Biol 2023; 2680:29-54. [PMID: 37428369 DOI: 10.1007/978-1-0716-3275-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
In planarian flatworms, piRNAs and SMEDWI (Schmidtea mediterranea PIWI) proteins are both essential for the animals' impressive regenerative ability and for their survival. A knockdown of SMEDWI proteins disrupts the specification of the planarian germline and impairs stem cell differentiation, resulting in lethal phenotypes. As the molecular targets of PIWI proteins and thus their biological function are determined by PIWI-bound small RNAs, termed piRNAs (for PIWI-interacting RNAs), it is imperative to study the wealth of PIWI-bound piRNAs using next-generation sequencing-based techniques. Prior to sequencing, piRNAs bound to individual SMEDWI proteins must be isolated. To that end, we established an immunoprecipitation protocol that can be applied to all planarian SMEDWI proteins. Co-immunoprecipitated piRNAs are visualized by using qualitative radioactive 5'-end labeling, which detects even trace amounts of small RNAs. Next, isolated piRNAs are subjected to a library preparation protocol that has been optimized for the efficient capture of piRNAs, whose 3'-ends carry a 2'-O-methyl modification. Successfully prepared piRNA libraries are subjected to Illumina-based next-generation sequencing. Obtained data are analyzed as presented in the accompanying manuscript.
Collapse
Affiliation(s)
- Iana V Kim
- RNA Biochemistry, University of Bayreuth, Bayreuth, Germany
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Tim Demtröder
- RNA Biochemistry, University of Bayreuth, Bayreuth, Germany
| | - Claus-D Kuhn
- RNA Biochemistry, University of Bayreuth, Bayreuth, Germany.
| |
Collapse
|
2
|
Sex-inducing effects toward planarians widely present among parasitic flatworms. iScience 2022; 26:105776. [PMID: 36594009 PMCID: PMC9804148 DOI: 10.1016/j.isci.2022.105776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 09/28/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Various parasitic flatworms infect vertebrates for sexual reproduction, often causing devastating diseases in their hosts. Consequently, flatworms are of great socioeconomic and biomedical importance. Although the cessation of parasitic flatworm sexual reproduction is a major target of anti-parasitic drug design, little is known regarding bioactive compounds controlling flatworm sexual maturation. Using the planarian Dugesia ryukyuensis, we observed that sex-inducing substances found in planarians are also widespread in parasitic flatworms, such as monogeneans and flukes (but not in tapeworms). Reverse-phase HPLC analysis revealed the sex-inducing substance(s) eluting around the tryptophan retention time in the fluke Calicophoron calicophorum, consistent with previous studies on the planarian Bipalium nobile, suggesting that the substance(s) is likely conserved among flatworms. Moreover, six of the 18 ovary-inducing substances identified via transcriptome and metabolome analyses are involved in purine metabolism. Our findings provide a basis for understanding and modifying the life cycles of various parasitic flatworms.
Collapse
|
3
|
A Krüppel-like factor is required for development and regeneration of germline and yolk cells from somatic stem cells in planarians. PLoS Biol 2022; 20:e3001472. [PMID: 35839223 PMCID: PMC9286257 DOI: 10.1371/journal.pbio.3001472] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 06/13/2022] [Indexed: 12/02/2022] Open
Abstract
Sexually reproducing animals segregate their germline from their soma. In addition to gamete-producing gonads, planarian and parasitic flatworm reproduction relies on yolk cell–generating accessory reproductive organs (vitellaria) supporting development of yolkless oocytes. Despite the importance of vitellaria for flatworm reproduction (and parasite transmission), little is known about this unique evolutionary innovation. Here, we examine reproductive system development in the planarian Schmidtea mediterranea, in which pluripotent stem cells generate both somatic and germ cell lineages. We show that a homolog of the pluripotency factor Klf4 is expressed in primordial germ cells (PGCs), presumptive germline stem cells (GSCs), and yolk cell progenitors. Knockdown of this klf4-like (klf4l) gene results in animals that fail to specify or maintain germ cells; surprisingly, they also fail to maintain yolk cells. We find that yolk cells display germ cell–like attributes and that vitellaria are structurally analogous to gonads. In addition to identifying a new proliferative cell population in planarians (yolk cell progenitors) and defining its niche, our work provides evidence supporting the hypothesis that flatworm germ cells and yolk cells share a common evolutionary origin.
Collapse
|
4
|
Liu S, Chen M, Liu X, Zheng K, Liu B, Wu W, Pang Q. DjApi5 is required for homeostasis in planarian Dugesia japonica. Biochem Biophys Res Commun 2022; 597:140-146. [PMID: 35144177 DOI: 10.1016/j.bbrc.2022.01.125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 01/30/2022] [Indexed: 11/25/2022]
Abstract
Orchestrated apoptosis in planarian Dugesia japonica is very important for its degrowth and regeneration. Apoptosis Inhibitor-5 (API5) is an anti-apoptotic factor that negatively regulates cell apoptosis. We characterized the conserved structure of DjApi5, however, the biological function of DjApi5 in planarians needs further investigation. In this study, we found that DjApi5 and its interacting molecular DjAcinus are required for planarian homeostasis, which may be correlated with their specific localization in neoblasts in addition to their anti-apoptosis functions. We further demonstrated the increased expression of DjApi5 during planarian regeneration, and DjApi5 deficiency affects normal regeneration processes. These results indicated new functions of DjApi5 in development.
Collapse
Affiliation(s)
- Shuo Liu
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, China.
| | - Meishan Chen
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, China.
| | - Xi Liu
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, China.
| | - Kang Zheng
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, China.
| | - Baohua Liu
- Shenzhen University of Health Science Center, Shenzhen, 518060, China.
| | - Weiwei Wu
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, China.
| | - Qiuxiang Pang
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, China.
| |
Collapse
|
5
|
Kawase O, Iwaya H, Asano Y, Inoue H, Kudo S, Sasahira M, Azuma N, Kondoh D, Ichikawa-Seki M, Xuan X, Sakamoto K, Okamoto H, Nakadate H, Inoue W, Saito I, Narita M, Sekii K, Kobayashi K. Identification of novel yolk ferritins unique to planarians: planarians supply aluminum rather than iron to vitellaria in egg capsules. Cell Tissue Res 2021; 386:391-413. [PMID: 34319433 DOI: 10.1007/s00441-021-03506-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 07/07/2021] [Indexed: 11/29/2022]
Abstract
All animals, other than Platyhelminthes, produce eggs containing yolk, referred to as "entolecithal" eggs. However, only Neoophora, in the phylum Platyhelminthes, produce "ectolecithal" eggs (egg capsules), in which yolk is stored in the vitelline cells surrounding oocytes. Vitelline cells are derived from vitellaria (yolk glands). Vitellaria are important reproductive organs that may be studied to elucidate unique mechanisms that have been evolutionarily conserved within Platyhelminthes. Currently, only limited molecular level information is available on vitellaria. The current study identified major vitellaria-specific proteins in a freshwater planarian, Dugesia ryukyuensis, using peptide mass fingerprinting (PMF) and expression analyses. Amino acid sequence analysis and orthology analysis via OrthoFinder ver.2.3.8 indicated that the identified major vitellaria-specific novel yolk ferritins were conserved in planarians (Tricladida). Because ferritins play an important role in Fe (iron) storage, we examined the metal elements contained in vitellaria and ectolecithal eggs, using non-heme iron histochemistry, elemental analysis based on inductively coupled plasma mass spectrometry and transmission electron microscopy- energy-dispersive X-ray spectroscopy analysis. Interestingly, vitellaria and egg capsules contained large amounts of aluminum (Al), but not Fe. The knockdown of the yolk ferritin genes caused a decrease in the volume of egg capsules, abnormality in juveniles, and increase in Al content in vitellaria. Yolk ferritins of D. ryukyuensis may regulate Al concentration in vitellaria via their pooling function of Al and protect the egg capsule production and normal embryogenesis from Al toxicity.
Collapse
Affiliation(s)
- Osamu Kawase
- Department of Biology, Premedical Sciences, Dokkyo Medical University, Mibu-machi, Shimotsuga-gun, Tochigi, 321-0293, Japan
| | - Hisashi Iwaya
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Yoshiya Asano
- Department of Neuroanatomy, Cell Biology and Histology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, Aomori, 036-8562, Japan
| | - Hiromoto Inoue
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Seiya Kudo
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Motoki Sasahira
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Nobuyuki Azuma
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Daisuke Kondoh
- Department of Basic Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Inaba-cho, Obihiro, Hokkaido, 080-8555, Japan
| | - Madoka Ichikawa-Seki
- Laboratory of Veterinary Parasitology, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, 020-8550, Japan
| | - Xuenan Xuan
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inaba-cho, Obihiro, Hokkaido, 080-8555, Japan
| | - Kimitoshi Sakamoto
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Hikaru Okamoto
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Hinaki Nakadate
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Wataru Inoue
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Ikuma Saito
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Miyu Narita
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Kiyono Sekii
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Kazuya Kobayashi
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan.
| |
Collapse
|
6
|
Kimoto C, Nakagawa H, Hasegawa R, Nodono H, Matsumoto M. Co-localization of DrPiwi-1 and DrPiwi-2 in the oogonial cytoplasm is essential for oocyte differentiation in sexualized planarians. Cells Dev 2021; 167:203710. [PMID: 34171535 DOI: 10.1016/j.cdev.2021.203710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/02/2021] [Accepted: 06/11/2021] [Indexed: 11/18/2022]
Abstract
P-Element-induced wimpy testis (Piwi) subfamily proteins form complexes that bind to Piwi-interacting RNA. This interaction is crucial for stem cell regulation and formation, maintenance of germline stem cells, and gametogenesis in several metazoans. Planarians are effective models for studying stem cells. In the planarian Dugesia ryukyuensis, DrPiwi-1 is essential for the development of germ cells, but not somatic cells and sexual organs. DrPiwi-2 is indispensable for regeneration. In this study, we aimed to investigate the effects of Piwi on the differentiation of germ cells using monoclonal antibodies against DrPiwi-1 and DrPiwi-2. DrPiwi-1 and DrPiwi-2 co-localized more in immature germ cells than in mature germ cells in the ovary. DrPiwi-1 was found in the cytoplasm of early oogonia as undifferentiated germ cells, whereas DrPiwi-2 was found to localize not only in the nuclei but also in the cytoplasm of early oogonia. In descendant germ cells (oocytes), DrPiwi-2 was not present in the cytoplasm, but was strongly detected in the nucleolus. Moreover, we found that DrPiwi-1 forms a complex with DrPiwi-2. The cause of DrPiwi-1 depletion may be the severe reduction in the DrPiwi-2 level in the cytoplasm of oogonia. These results suggest that the formation of the DrPiwi-1 and DrPiwi-2 complex in the cytoplasm of oogonia is essential for oocyte differentiation. Our findings support the conclusion that DrPiwi-1 forms a complex with DrPiwi-2 in the cytoplasm of undifferentiated germ cells, and it signifies the start of gametogenesis. In contrast, in the testes, Drpiwi-1 was found in undifferentiated germ cells (spermatogonia), whereas DrPiwi-2 was found in descendant germ cells (spermatocytes). The process of germ cell differentiation from adult stem cells in planarians may be regulated in different ways in female and male germ lines by the Piwi family.
Collapse
Affiliation(s)
- Chiaki Kimoto
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Haruka Nakagawa
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Reiko Hasegawa
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Hanae Nodono
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Midori Matsumoto
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan.
| |
Collapse
|
7
|
Maezawa T, Ishikawa M, Sekii K, Nagamatsu G, Furukawa R, Kobayashi K. D-Tryptophan enhances the reproductive organ-specific expression of the amino acid transporter homolog Dr-SLC38A9 involved in the sexual induction of planarian Dugesia ryukyuensis. ZOOLOGICAL LETTERS 2021; 7:4. [PMID: 33743841 PMCID: PMC7981857 DOI: 10.1186/s40851-021-00173-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 03/10/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Many animals switch between asexual and sexual reproduction in nature. We previously established a system for the sexual induction of planarian Dugesia ryukyuensis by feeding asexual planarians with minced sexual planarians. We identified DL-tryptophan (Trp) as one of the sex-inducing substances. DL-Trp can induce ovarian development, the first and essential step of sexual induction. D-Trp must act as a principal bioactive compound in terms of ovarian development, because the ovary-inducing activity of D-Trp was 500 times more potent than that of L-Trp. However, how Trp controls sexual induction is still unknown. RESULTS In this study, qRT-PCR analyses suggested that the putative amino acid transporter gene Dr-SLC38A9 is highly expressed in sexual worms, especially in the yolk glands. In situ hybridization analyses showed that Dr-SLC38A9 is expressed in the ovarian primordia of asexual worms and in the mature ovaries, testes, and yolk glands of sexual worms. In addition, Dr-SLC38A9 RNA interference during sexual induction resulted in the suppression of the development of reproductive organs. These results suggest that Dr-SLC38A9 is involved in the development of these organs. Moreover, we demonstrated that the reproductive organ-specific expression of Dr-SLC38A9 is enhanced by the addition of D-Trp. CONCLUSION We propose that D-Trp activates the expression of Dr-SLC38A9 to promote sexual induction in the planarian D. ryukyuensis.
Collapse
Affiliation(s)
- Takanobu Maezawa
- Advanced Science Course, Department of Integrated Science and Technology, National Institute of Technology, Tsuyama College, 624-1 Numa, Tsuyama, Okayama, 708-8509, Japan.
| | - Masaki Ishikawa
- Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Kiyono Sekii
- Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Go Nagamatsu
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Ryohei Furukawa
- Department of Biology, Research and Education Center for Natural Sciences, Keio University, 4-1-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8521, Japan
| | - Kazuya Kobayashi
- Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan.
| |
Collapse
|
8
|
Xu CM, Sun SC. Expression of Piwi Genes during the Regeneration of Lineus sanguineus (Nemertea, Pilidiophora, Heteronemertea). Genes (Basel) 2020; 11:E1484. [PMID: 33321919 PMCID: PMC7764242 DOI: 10.3390/genes11121484] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/18/2020] [Accepted: 12/08/2020] [Indexed: 12/19/2022] Open
Abstract
The transposon silencer piwi genes play important roles in germline determination and maintenance, gametogenesis, and stem-cell self-renewal, and the expression of certain piwi genes is indispensable for regeneration. Knowledge about piwi genes is needed for phylum Nemertea, which contains members (e.g., Lineus sanguineus) with formidable regeneration capacity. By searching the L. sanguineus genome, we identified six Argonaute genes including three ago (Ls-Ago2, Ls-Ago2a, and Ls-Ago2b) and three piwi (Ls-piwi1, Ls-piwi2, and Ls-piwi3) genes. In situ hybridization revealed that, in intact females, Ls-piwi2 and Ls-piwi3 were not expressed, while Ls-piwi1 was expressed in ovaries. During regeneration, Ls-piwi1 and Ls-pcna (proliferating cell nuclear antigen) had strong and similar expressions. The expression of Ls-piwi1 became indetectable while Ls-pcna continued to be expressed when the differentiation of new organs was finished. During anterior regeneration, expression signals of Ls-piwi2 and Ls-piwi3 were weak and only detected in the blastema stage. During posterior regeneration, no expression was observed for Ls-piwi2. To date, no direct evidence has been found for the existence of congenital stem cells in adult L. sanguineus. The "pluripotent cells" in regenerating tissues are likely to be dedifferentiated from other type(s) of cells.
Collapse
Affiliation(s)
| | - Shi-Chun Sun
- College of Fisheries, Institute of Evolution and Marine Biodiversity, Ocean University of China, 5 Yushan Road, Qingdao 266003, China;
| |
Collapse
|
9
|
Sun ZH, Wei JL, Cui ZP, Han YL, Zhang J, Song J, Chang YQ. Identification and functional characterization of piwi1 gene in sea cucumber, Apostichopus japonicas. Comp Biochem Physiol B Biochem Mol Biol 2020; 252:110536. [PMID: 33212209 DOI: 10.1016/j.cbpb.2020.110536] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/03/2020] [Accepted: 11/12/2020] [Indexed: 02/04/2023]
Abstract
The sea cucumber (Apostichopus japonicus) is an economically important mariculture species in Asia. However, the genetic breeding of sea cucumbers is difficult because the sexes cannot be identified by appearance. Therefore, studies on sex-related genes are helpful in revealing the mechanisms of sex determination and differentiation in sea cucumbers. P-element induced wimpy testis (piwi) is a germ cell marker involved in gametogenesis in vertebrates; however, the expression pattern and function during gametogenesis remain unclear in sea cucumbers. In this study, we identified a piwi homolog gene in A. japonicus (Ajpiwi1) and investigated its expression pattern, and function. Ajpiwi1 is a maternal factor and is ubiquitously expressed in adult tissues, including the ovary and testis. Ajpiwi1 expression is strong in early oocytes, spermatocytes, and spermatogonia; weak in mature oocytes; and undetected in spermatids and intra-gonadal somatic cells. The knockdown of Ajpiwi1 by RNA interference (RNAi) led to the downregulation of other conserved sex-related genes such as dmrt1, foxl2, and germ cell-less. Therefore, Ajpiwi1 might play a critical role during gametogenesis in A. japonicus. This study creates new possibilities for studying sex-related gene functions in the sea cucumber and builds a gene function research platform based on RNAi for the first time.
Collapse
Affiliation(s)
- Zhi-Hui Sun
- Key Laboratory of Mariculture& Stock Enhancement in North China Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian 116023, China
| | - Jin-Liang Wei
- Key Laboratory of Mariculture& Stock Enhancement in North China Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian 116023, China
| | - Zhou-Ping Cui
- Key Laboratory of Mariculture& Stock Enhancement in North China Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian 116023, China
| | - Ya-Lun Han
- Key Laboratory of Mariculture& Stock Enhancement in North China Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian 116023, China
| | - Jian Zhang
- Key Laboratory of Mariculture& Stock Enhancement in North China Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian 116023, China
| | - Jian Song
- Key Laboratory of Mariculture& Stock Enhancement in North China Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian 116023, China
| | - Ya-Qing Chang
- Key Laboratory of Mariculture& Stock Enhancement in North China Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian 116023, China.
| |
Collapse
|
10
|
Kim IV, Riedelbauch S, Kuhn CD. The piRNA pathway in planarian flatworms: new model, new insights. Biol Chem 2020; 401:1123-1141. [DOI: 10.1515/hsz-2019-0445] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/12/2020] [Indexed: 12/22/2022]
Abstract
AbstractPIWI-interacting RNAs (piRNAs) are small regulatory RNAs that associate with members of the PIWI clade of the Argonaute superfamily of proteins. piRNAs are predominantly found in animal gonads. There they silence transposable elements (TEs), regulate gene expression and participate in DNA methylation, thus orchestrating proper germline development. Furthermore, PIWI proteins are also indispensable for the maintenance and differentiation capabilities of pluripotent stem cells in free-living invertebrate species with regenerative potential. Thus, PIWI proteins and piRNAs seem to constitute an essential molecular feature of somatic pluripotent stem cells and the germline. In keeping with this hypothesis, both PIWI proteins and piRNAs are enriched in neoblasts, the adult stem cells of planarian flatworms, and their presence is a prerequisite for the proper regeneration and perpetual tissue homeostasis of these animals. The piRNA pathway is required to maintain the unique biology of planarians because, in analogy to the animal germline, planarian piRNAs silence TEs and ensure stable genome inheritance. Moreover, planarian piRNAs also contribute to the degradation of numerous protein-coding transcripts, a function that may be critical for neoblast differentiation. This review gives an overview of the planarian piRNA pathway and of its crucial function in neoblast biology.
Collapse
Affiliation(s)
- Iana V. Kim
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
| | - Sebastian Riedelbauch
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
| | - Claus-D. Kuhn
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
| |
Collapse
|
11
|
Kashima M, Agata K, Shibata N. What is the role of PIWI family proteins in adult pluripotent stem cells? Insights from asexually reproducing animals, planarians. Dev Growth Differ 2020; 62:407-422. [PMID: 32621324 DOI: 10.1111/dgd.12688] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/26/2020] [Accepted: 06/09/2020] [Indexed: 02/06/2023]
Abstract
Planarians have a remarkable regenerative ability owing to their adult pluripotent stem cells (aPSCs), which are called "neoblasts." Planarians maintain a considerable number of neoblasts throughout their adulthood to supply differentiated cells for the maintenance of tissue homeostasis and asexual reproduction (fission followed by regeneration). Thus, planarians serve as a good model to study the regulatory mechanisms of in vivo aPSCs. In asexually reproducing invertebrates, such as sponge, Hydra, and planaria, piwi family genes are the markers most commonly expressed in aPSCs. While piwi family genes are known as guardians against transposable elements in the germline cells of animals that only sexually propagate, their functions in the aPSC system have remained elusive. In this review, we introduce recent knowledge on the PIWI family proteins in the aPSC system in planarians and other organisms and discuss how PIWI family proteins contribute to the regulation of the aPSC system.
Collapse
Affiliation(s)
- Makoto Kashima
- College of Science and Engineering, Aoyama Gakuin University, Sagamihara Chuo Ku, Japan
| | - Kiyokazu Agata
- National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
| | - Norito Shibata
- Department of Integrated Science and Technology, National Institute of Technology, Tsuyama College, Tsuyama-City, Japan
| |
Collapse
|
12
|
Wang C, Yang ZZ, Guo FH, Shi S, Han XS, Zeng A, Lin H, Jing Q. Heat shock protein DNAJA1 stabilizes PIWI proteins to support regeneration and homeostasis of planarian Schmidtea mediterranea. J Biol Chem 2019; 294:9873-9887. [PMID: 31076507 DOI: 10.1074/jbc.ra118.004445] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 04/25/2019] [Indexed: 12/16/2022] Open
Abstract
PIWI proteins are key regulators of germline and somatic stem cells throughout different evolutionary lineages. However, how PIWI proteins themselves are regulated remains largely unknown. To identify candidate proteins that interact with PIWI proteins and regulate their stability, here we established a yeast two-hybrid (Y2H) assay in the planarian species Schmidtea mediterranea We show that DNAJA1, a heat shock protein 40 family member, interacts with the PIWI protein SMEDWI-2, as validated by the Y2H screen and co-immunoprecipitation assays. We found that DNAJA1 is enriched in planarian adult stem cells, the nervous system, and intestinal tissues. DNAJA1-knockdown abolished planarian regeneration and homeostasis, compromised stem cell maintenance and PIWI-interacting RNA (piRNA) biogenesis, and deregulated SMEDWI-1/2 target genes. Mechanistically, we observed that DNAJA1 is required for the stability of SMEDWI-1 and SMEDWI-2 proteins. Furthermore, we noted that human DNAJA1 binds to Piwi-like RNA-mediated gene silencing 1 (PIWIL1) and is required for PIWIL1 stability in human gastric cancer cells. In summary, our results reveal not only an evolutionarily conserved functional link between PIWI and DNAJA1 that is essential for PIWI protein stability and piRNA biogenesis, but also an important role of DNAJA1 in the control of proteins involved in stem cell regulation.
Collapse
Affiliation(s)
- Chen Wang
- From the Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China.,the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| | - Zhen-Zhen Yang
- From the Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Fang-Hao Guo
- the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| | - Shuo Shi
- From the Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Xiao-Shuai Han
- the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| | - An Zeng
- the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| | - Haifan Lin
- From the Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China, .,the Yale Stem Cell Center, Yale School of Medicine, New Haven, Connecticut 06511
| | - Qing Jing
- the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| |
Collapse
|
13
|
Issigonis M, Newmark PA. From worm to germ: Germ cell development and regeneration in planarians. Curr Top Dev Biol 2019; 135:127-153. [DOI: 10.1016/bs.ctdb.2019.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
14
|
Nakagawa H, Sekii K, Maezawa T, Kitamura M, Miyashita S, Abukawa M, Matsumoto M, Kobayashi K. A comprehensive comparison of sex-inducing activity in asexual worms of the planarian Dugesia ryukyuensis: the crucial sex-inducing substance appears to be present in yolk glands in Tricladida. ZOOLOGICAL LETTERS 2018; 4:14. [PMID: 29942643 PMCID: PMC5996458 DOI: 10.1186/s40851-018-0096-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 05/11/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Turbellarian species can post-embryonically produce germ line cells from pluripotent stem cells called neoblasts, which enables some of them to switch between an asexual and a sexual state in response to environmental changes. Certain low-molecular-weight compounds contained in sexually mature animals act as sex-inducing substances that trigger post-embryonic germ cell development in asexual worms of the freshwater planarian Dugesia ryukyuensis (Tricladida). These sex-inducing substances may provide clues to the molecular mechanism of this reproductive switch. However, limited information about these sex-inducing substances is available. RESULTS Our assay system based on feeding sex-inducing substances to asexual worms of D. ryukyuensis is useful for evaluating sex-inducing activity. We used the freshwater planarians D. ryukyuensis and Bdellocephala brunnea (Tricladida), land planarian Bipalium nobile (Tricladida), and marine flatworm Thysanozoon brocchii (Polycladida) as sources of the sex-inducing substances. Using an assay system, we showed that the three Tricladida species had sufficient sex-inducing activity to fully induce hermaphroditic reproductive organs in asexual worms of D. ryukyuensis. However, the sex-inducing activity of T. brocchii was sufficient only to induce a pair of ovaries. We found that yolk glands, which are found in Tricladida but not Polycladida, may contain the sex-inducing substance that can fully sexualize asexual worms of D. ryukyuensis. CONCLUSIONS Our results suggest that within Tricladida, there are one or more common compounds or functional analogs capable of fully sexualizing asexual worms of D. ryukyuensis; namely, the crucial sex-inducing substance (hydrophilic and heat-stable, but not a peptide) produced in yolk glands.
Collapse
Affiliation(s)
- Haruka Nakagawa
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561 Japan
| | - Kiyono Sekii
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561 Japan
| | - Takanobu Maezawa
- Advanced Science Course, Department of Integrated Science and Technology, National Institute of Technology, Tsuyama College, 624-1 Numa, Tsuyama, Okayama, 708-8509 Japan
| | - Makoto Kitamura
- Center for Integrated Medical Research, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan
| | - Soichiro Miyashita
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561 Japan
| | - Marina Abukawa
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561 Japan
| | - Midori Matsumoto
- Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama, 223-8522 Japan
| | - Kazuya Kobayashi
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561 Japan
| |
Collapse
|
15
|
Alam MS, Moriyama H, Matsumoto M. Inhibition of Dr-dut gene causes DNA damage in planarian. Mol Reprod Dev 2018; 85:188-196. [PMID: 29405473 DOI: 10.1002/mrd.22952] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/27/2017] [Indexed: 02/02/2023]
Abstract
The DUT gene encodes Deoxyuridine triphosphatase (dUTPase), which is involved in nucleotide metabolism. dUTPase prevents uracil misincorporation in DNA by balancing the intracellular ratio between dUTP and dTTP. This study aimed to investigate the role of Dr-dut gene in the planarian Dugesia ryukyuensis by assessing the consequences of Dr-dut silencing on known phenomena, including regeneration following amputation and radiation damage. We functionally disrupted planarian Dr-dut mRNA by feeding RNAi-containing food to animals. Dr-dut RNAi resulted in the death of planarians in 28 days, and elevated double-stranded DNA breakage. Expression of the DNA damage response gene Dr-atm and the DNA repair genes Dr-rad51 and Dr-rad51c temporarily increased, and then decreased following the onset of feeding. When RNAi-treated planarians were amputated, both head and tail parts failed to regenerate, and the animals died in 25 and 29 days, respectively. Administration of 5-fluorouracil (5-FU) also resulted in death and DNA damage, and synergistically caused higher genotoxicity in planarian fed Dr-dut RNAi-containing food.
Collapse
Affiliation(s)
- Md Shahanoor Alam
- Department of Bioscience and Informatics, Keio University, Yokohama, Kanagawa, Japan
| | - Hideaki Moriyama
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Midori Matsumoto
- Department of Bioscience and Informatics, Keio University, Yokohama, Kanagawa, Japan
| |
Collapse
|
16
|
Rink JC. Stem Cells, Patterning and Regeneration in Planarians: Self-Organization at the Organismal Scale. Methods Mol Biol 2018; 1774:57-172. [PMID: 29916155 DOI: 10.1007/978-1-4939-7802-1_2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The establishment of size and shape remains a fundamental challenge in biological research that planarian flatworms uniquely epitomize. Planarians can regenerate complete and perfectly proportioned animals from tiny and arbitrarily shaped tissue pieces; they continuously renew all organismal cell types from abundant pluripotent stem cells, yet maintain shape and anatomy in the face of constant turnover; they grow when feeding and literally degrow when starving, while scaling form and function over as much as a 40-fold range in body length or an 800-fold change in total cell numbers. This review provides a broad overview of the current understanding of the planarian stem cell system, the mechanisms that pattern the planarian body plan and how the interplay between patterning signals and cell fate choices orchestrates regeneration. What emerges is a conceptual framework for the maintenance and regeneration of the planarian body plan on basis of the interplay between pluripotent stem cells and self-organizing patterns and further, the general utility of planarians as model system for the mechanistic basis of size and shape.
Collapse
Affiliation(s)
- Jochen C Rink
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
| |
Collapse
|
17
|
Özpolat BD, Handberg-Thorsager M, Vervoort M, Balavoine G. Cell lineage and cell cycling analyses of the 4d micromere using live imaging in the marine annelid Platynereis dumerilii. eLife 2017; 6:30463. [PMID: 29231816 PMCID: PMC5764573 DOI: 10.7554/elife.30463] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 12/11/2017] [Indexed: 11/13/2022] Open
Abstract
Cell lineage, cell cycle, and cell fate are tightly associated in developmental processes, but in vivo studies at single-cell resolution showing the intricacies of these associations are rare due to technical limitations. In this study on the marine annelid Platynereis dumerilii, we investigated the lineage of the 4d micromere, using high-resolution long-term live imaging complemented with a live-cell cycle reporter. 4d is the origin of mesodermal lineages and the germline in many spiralians. We traced lineages at single-cell resolution within 4d and demonstrate that embryonic segmental mesoderm forms via teloblastic divisions, as in clitellate annelids. We also identified the precise cellular origins of the larval mesodermal posterior growth zone. We found that differentially-fated progeny of 4d (germline, segmental mesoderm, growth zone) display significantly different cell cycling. This work has evolutionary implications, sets up the foundation for functional studies in annelid stem cells, and presents newly established techniques for live imaging marine embryos.
Collapse
|
18
|
Almazan EMP, Lesko SL, Markey MP, Rouhana L. Girardia dorotocephala transcriptome sequence, assembly, and validation through characterization of piwi homologs and stem cell progeny markers. Dev Biol 2017; 433:433-447. [PMID: 28774726 PMCID: PMC5750089 DOI: 10.1016/j.ydbio.2017.07.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 07/05/2017] [Accepted: 07/27/2017] [Indexed: 12/20/2022]
Abstract
Planarian flatworms are popular models for the study of regeneration and stem cell biology in vivo. Technical advances and increased availability of genetic information have fueled the discovery of molecules responsible for stem cell pluripotency and regeneration in flatworms. Unfortunately, most of the planarian research performed worldwide utilizes species that are not natural habitants of North America, which limits their availability to newcomer laboratories and impedes their distribution for educational activities. In order to circumvent these limitations and increase the genetic information available for comparative studies, we sequenced the transcriptome of Girardia dorotocephala, a planarian species pandemic and commercially available in North America. A total of 254,802,670 paired sequence reads were obtained from RNA extracted from intact individuals, regenerating fragments, as well as freshly excised auricles of a clonal line of G. dorotocephala (MA-C2), and used for de novo assembly of its transcriptome. The resulting transcriptome draft was validated through functional analysis of genetic markers of stem cells and their progeny in G. dorotocephala. Akin to orthologs in other planarian species, G. dorotocephala Piwi1 (GdPiwi1) was found to be a robust marker of the planarian stem cell population and GdPiwi2 an essential component for stem cell-driven regeneration. Identification of G. dorotocephala homologs of the early stem cell descendent marker PROG-1 revealed a family of lysine-rich proteins expressed during epithelial cell differentiation. Sequences from the MA-C2 transcriptome were found to be 98-99% identical to nucleotide sequences from G. dorotocephala populations with different chromosomal number, demonstrating strong conservation regardless of karyotype evolution. Altogether, this work establishes G. dorotocephala as a viable and accessible option for analysis of gene function in North America.
Collapse
Affiliation(s)
- Eugene Matthew P Almazan
- Department of Biological Sciences, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, United States
| | - Sydney L Lesko
- Department of Biological Sciences, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, United States
| | - Michael P Markey
- Department of Biochemistry and Molecular Biology, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, United States
| | - Labib Rouhana
- Department of Biological Sciences, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, United States.
| |
Collapse
|
19
|
The identification of ᴅ-tryptophan as a bioactive substance for postembryonic ovarian development in the planarian Dugesia ryukyuensis. Sci Rep 2017; 7:45175. [PMID: 28338057 PMCID: PMC5364533 DOI: 10.1038/srep45175] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 02/20/2017] [Indexed: 12/24/2022] Open
Abstract
Many metazoans start germ cell development during embryogenesis, while some metazoans possessing pluripotent stem cells undergo postembryonic germ cell development. The latter reproduce asexually but develop germ cells from pluripotent stem cells or dormant primordial germ cells when they reproduce sexually. Sexual induction of the planarian Dugesia ryukyuensis is an important model for postembryonic germ cell development. In this experimental system, hermaphroditic reproductive organs are differentiated in presumptive gonadal regions by the administration of a crude extract from sexual planarians to asexual ones. However, the substances involved in the first event during postembryonic germ cell development, i.e., ovarian development, remain unknown. Here, we aimed to identify a bioactive compound associated with postembryonic ovarian development. Bioassay-guided fractionation identified ʟ-tryptophan (Trp) on the basis of electrospray ionization–mass spectrometry, circular dichroism, and nuclear magnetic resonance spectroscopy. Originally masked by a large amount of ʟ-Trp, ᴅ-Trp was detected by reverse-phase high-performance liquid chromatography. The ovary-inducing activity of ᴅ-Trp was 500 times more potent than that of ʟ-Trp. This is the first report describing a role for an intrinsic ᴅ-amino acid in postembryonic germ cell development. Our findings provide a novel insight into the mechanisms of germ cell development regulated by low-molecular weight bioactive compounds.
Collapse
|
20
|
DONG Z, YUWEN Y, SIMA Y, DONG Y, ZHAN H, CHEN G, LIU D. Photokinesis andDjopsingene expression analysis during the regeneration of planarian eyes. Integr Zool 2017; 12:157-164. [DOI: 10.1111/1749-4877.12234] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Zimei DONG
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Yanqing YUWEN
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Yingxu SIMA
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Yanping DONG
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Huina ZHAN
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Guangwen CHEN
- College of Life Science; Henan Normal University; Xinxiang Henan China
| | - Dezeng LIU
- College of Life Science; Henan Normal University; Xinxiang Henan China
| |
Collapse
|
21
|
Gahan JM, Bradshaw B, Flici H, Frank U. The interstitial stem cells in Hydractinia and their role in regeneration. Curr Opin Genet Dev 2016; 40:65-73. [DOI: 10.1016/j.gde.2016.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 05/26/2016] [Accepted: 06/16/2016] [Indexed: 10/21/2022]
|
22
|
Shibata N, Kashima M, Ishiko T, Nishimura O, Rouhana L, Misaki K, Yonemura S, Saito K, Siomi H, Siomi M, Agata K. Inheritance of a Nuclear PIWI from Pluripotent Stem Cells by Somatic Descendants Ensures Differentiation by Silencing Transposons in Planarian. Dev Cell 2016; 37:226-37. [DOI: 10.1016/j.devcel.2016.04.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 01/18/2016] [Accepted: 04/11/2016] [Indexed: 11/29/2022]
|
23
|
Özpolat BD, Bely AE. Gonad establishment during asexual reproduction in the annelid Pristina leidyi. Dev Biol 2015; 405:123-36. [PMID: 26134407 DOI: 10.1016/j.ydbio.2015.06.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 03/15/2015] [Accepted: 06/02/2015] [Indexed: 11/29/2022]
Abstract
Animals that can reproduce by both asexual agametic reproduction and sexual reproduction must transmit or re-establish their germ line post-embryonically. Although such a dual reproductive mode has evolved repeatedly among animals, how asexually produced individuals establish their germ line remains poorly understood in most groups. We investigated germ line development in the annelid Pristina leidyi, a species that typically reproduces asexually by paratomic fission, intercalating a new tail and head in the middle of the body followed by splitting. We found that in fissioning individuals, gonads occur in anterior segments in the anterior-most individual as well as in new heads forming within fission zones. Homologs of the germ line/multipotency genes piwi, vasa, and nanos are expressed in the gonads, as well as in proliferative tissues including the posterior growth zone, fission zone, and regeneration blastema. In fissioning animals, certain cells on the ventral nerve cord express a homolog of piwi, are abundant near fission zones, and sometimes make contact with gonads. Such cells are typically undetectable near the blastema and posterior growth zone. Time-lapse imaging provides direct evidence that cells on the ventral nerve cord migrate preferentially towards fission zones. Our findings indicate that gonads form routinely in fissioning individuals, that a population of piwi-positive cells on the ventral nerve cord is associated with fission and gonads, and that cells resembling these piwi-positive cells migrate along the ventral nerve cord. We suggest that the piwi-positive ventral cells are germ cells that transmit the germ line across asexually produced individuals via migration along the ventral nerve cord.
Collapse
Affiliation(s)
- B Duygu Özpolat
- Department of Biology, University of Maryland, College Park, MD 20742, USA.
| | - Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD 20742, USA.
| |
Collapse
|
24
|
Maezawa T, Tanaka H, Nakagawa H, Ono M, Aoki M, Matsumoto M, Ishida T, Horiike K, Kobayashi K. Planarian D-amino acid oxidase is involved in ovarian development during sexual induction. Mech Dev 2014; 132:69-78. [PMID: 24434168 DOI: 10.1016/j.mod.2013.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/18/2013] [Accepted: 12/28/2013] [Indexed: 10/25/2022]
Abstract
To elucidate the molecular mechanisms underlying switching from asexual to sexual reproduction, namely sexual induction, we developed an assay system for sexual induction in the hermaphroditic planarian species Dugesia ryukyuensis. Ovarian development is the initial and essential step in sexual induction, and it is followed by the formation of other reproductive organs, including the testes. Here, we report a function of a planarian D-amino acid oxidase, Dr-DAO, in the control of ovarian development in planarians. Asexual worms showed significantly more widespread expression of Dr-DAO in the parenchymal space than did sexual worms. Inhibition of Dr-DAO by RNAi caused the formation of immature ovaries. In addition, we found that feeding asexual worms 5 specific D-amino acids could induce the formation of immature ovaries that are similar to those observed in Dr-DAO knockdown worms, suggesting that Dr-DAO inhibits the formation of immature ovaries by degrading these D-amino acids. Following sexual induction, Dr-DAO expression was observed in the ovaries. The knockdown of Dr-DAO during sexual induction delayed the maturation of the other reproductive organs, as well as ovary. These findings suggest that Dr-DAO acts to promote ovarian maturation and that complete sexual induction depends on the production of mature ovaries. We propose that Dr-DAO produced in somatic cells prevents the onset of sexual induction in the asexual state, and then after sexual induction, the female germ cells specifically produce Dr-DAO to induce full maturation. Therefore, Dr-DAO produced in somatic and female germline cells may play different roles in sexual induction.
Collapse
Affiliation(s)
- Takanobu Maezawa
- Division of General Education and Research, Tsuyama National College of Technology, 624-1 Numa, Tsuyama, Okayama 708-8509, Japan
| | - Hiroyuki Tanaka
- Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Seta, Ohtsu, Shiga 520-2192, Japan
| | - Haruka Nakagawa
- Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan
| | - Mizuki Ono
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Manabu Aoki
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Midori Matsumoto
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Tetsuo Ishida
- Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Seta, Ohtsu, Shiga 520-2192, Japan
| | - Kihachiro Horiike
- Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Seta, Ohtsu, Shiga 520-2192, Japan
| | - Kazuya Kobayashi
- Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan.
| |
Collapse
|
25
|
Abstract
Planarians are members of the Platyhelminthes (flatworms). These animals have evolved a remarkable stem cell system. A single pluripotent adult stem cell type ("neoblast") gives rise to the entire range of cell types and organs in the planarian body plan, including a brain, digestive-, excretory-, sensory- and reproductive systems. Neoblasts are abundantly present throughout the mesenchyme and divide continuously. The resulting stream of progenitors and turnover of differentiated cells drive the rapid self-renewal of the entire animal within a matter of weeks. Planarians grow and literally de-grow ("shrink") by the food supply-dependent adjustment of organismal turnover rates, scaling body plan proportions over as much as a 50-fold size range. Their dynamic body architecture further allows astonishing regenerative abilities, including the regeneration of complete and perfectly proportioned animals even from tiny tissue remnants. Planarians as an experimental system, therefore, provide unique opportunities for addressing a spectrum of current problems in stem cell research, including the evolutionary conservation of pluripotency, the dynamic organization of differentiation lineages and the mechanisms underlying organismal stem cell homeostasis. The first part of this review focuses on the molecular biology of neoblasts as pluripotent stem cells. The second part examines the fascinating mechanistic and conceptual challenges posed by a stem cell system that epitomizes a universal design principle of biological systems: the dynamic steady state.
Collapse
Affiliation(s)
- Jochen C Rink
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
| |
Collapse
|