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Adolfi MC, Depincé A, Wen M, Pan Q, Herpin A. Development of Ovaries and Sex Change in Fish: Bringing Potential into Action. Sex Dev 2023; 17:84-98. [PMID: 36878204 DOI: 10.1159/000526008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 07/08/2022] [Indexed: 03/08/2023] Open
Abstract
BACKGROUND Encompassing about half of the 60,000 species of vertebrates, fish display the greatest diversity of sex determination mechanisms among metazoans. As such that phylum offers a unique playground to study the impressive variety of gonadal morphogenetic strategies, ranging from gonochorism, with either genetic or environmental sex determination, to unisexuality, with either simultaneous or consecutive hermaphroditism. SUMMARY From the two main types of gonads, the ovaries embrace the important role to produce the larger and non-motile gametes, which is the basis for the development of a future organism. The production of the egg cells is complex and involves the formation of follicular cells, which are necessary for the maturation of the oocytes and the production of feminine hormones. In this vein, our review focuses on the development of ovaries in fish with special emphasis on the germ cells, including those that transition from one sex to the other as part of their life cycle and those that are capable of transitioning to the opposite sex depending on environmental cues. KEY MESSAGES Clearly, establishing an individual as either a female or a male is not accomplished by the sole development of two types of gonads. In most cases, that dichotomy, be it final or transient, is accompanied by coordinated transformations across the entire organism, leading to changes in the physiological sex as a whole. These coordinated transformations require both molecular and neuroendocrine networks, but also anatomical and behavioural adjustments. Remarkably, fish managed to tame the ins and outs of sex reversal mechanisms to take the most advantages of changing sex as adaptive strategies in some situations.
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Affiliation(s)
- Mateus Contar Adolfi
- Developmental Biochemistry, Biocenter, University of Würzburg, Würzburg, Germany
| | | | - Ming Wen
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Qiaowei Pan
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Amaury Herpin
- Fish Physiology and Genomics, INRAE, UR 1037, Rennes, France
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2
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Baloch AR, Franěk R, Saito T, Pšenička M. Dead-end (dnd) protein in fish-a review. FISH PHYSIOLOGY AND BIOCHEMISTRY 2021; 47:777-784. [PMID: 30671782 DOI: 10.1007/s10695-018-0606-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/28/2018] [Indexed: 06/09/2023]
Abstract
Dead end (dnd) is a germ plasm-specific maternal RNA discovered in zebrafish and then in other vertebrates. Dnd protein is essential for migration and motility of primordial germ cells (PGCs), only cells destined to transfer genetic information to offspring. PGCs arise far from somatic cells of developing gonads and they must migrate to their site of function. Migration of PGCs follows complex path by various developing tissues as their disruption impacts on the fertility. Recently, it has been found that dnd is not required for survival of PGCs and dnd-deficient zebrafish PGCs transdifferentiate into the somatic cells. In fish, targeting dnd causes removal of PGCs that ultimately affects sex differentiation. Sterility in various fish species can be achieved by knockdown or knockout of dnd. In our review, we have discussed dnd as a germ cell-specific molecular marker in fish, its interaction with miRNAs, and its use in aquaculture and fish conservation.
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Affiliation(s)
- Abdul Rasheed Baloch
- South Bohemian Research Center for Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice, Zatisi 728/II, 389 25, Vodnany, Czech Republic.
| | - Roman Franěk
- South Bohemian Research Center for Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice, Zatisi 728/II, 389 25, Vodnany, Czech Republic
| | - Taiju Saito
- South Bohemian Research Center for Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice, Zatisi 728/II, 389 25, Vodnany, Czech Republic
- Nishiura Station, South Ehime Fisheries Research Center, Ehime University, Uchidomari, Ainan, Ehime, 798-4206, Japan
| | - Martin Pšenička
- South Bohemian Research Center for Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice, Zatisi 728/II, 389 25, Vodnany, Czech Republic
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3
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Presence of the matrix metalloproteinases during the migration of the primordial germ cells in zebrafish gonadal ridge. Cell Tissue Res 2020; 383:707-722. [PMID: 32960354 DOI: 10.1007/s00441-020-03288-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 08/18/2020] [Indexed: 01/20/2023]
Abstract
In vertebrates, the primordial germ cells (PGCs) differentiate from extragonadal regions, migrating to gonadal ridge during the embryonic development. However, recent studies in mammals indicate that the PGCs originate from the epiblast and subsequently migrate into the yolk sac. Cell and molecular bases involved in routes during the migration of these cells are still not well understood. Thus, in an attempt to evaluate the participation of matrix metalloproteinases (MMPs) during the gonadal primordium formation in Danio rerio (zebrafish), the route of migration of PGCs was analyzed. In zebrafish, during the migration of the PGCs to the forming gonad, they bind by cytoplasmic processes to the extracellular matrix and migrate through amoeboid movements until they reach the gonadal ridge. During the epiboly, MMPs were not detected. However, after organogenesis, three MMP types were expressed in the somatic cells that were located ahead of the PGCs in the migration route. This expression was maintained throughout the mesentery and was not detected in the PGCs. Upon reaching the gonadal ridge, the PGCs and somatic cells express MMPs and epithelium begins to be formed. After the formation of the basement membrane, the germinal epithelium is delineated by the somatic cells, which remodeling the extracellular matrix. So, a PGC organization occurs through the tissue, forming the gonadal primordium. Concomitantly, granulocytes expressing different MMPs are present. This data in exposing the role of MMPs during the PGC migration to the forming gonad, may point a new way in understanding the reproductive biology of the vertebrates in general.
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Nakamura S, Hira S, Fujiwara M, Miyagata N, Tsuji T, Kondo A, Kimura H, Shinozuka Y, Hayashi M, Kobayashi S, Mukai M. A truncated form of a transcription factor Mamo activates vasa in Drosophila embryos. Commun Biol 2019; 2:422. [PMID: 31799425 PMCID: PMC6868150 DOI: 10.1038/s42003-019-0663-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 10/25/2019] [Indexed: 12/17/2022] Open
Abstract
Expression of the vasa gene is associated with germline establishment. Therefore, identification of vasa activator(s) should provide insights into germline development. However, the genes sufficient for vasa activation remain unknown. Previously, we showed that the BTB/POZ-Zn-finger protein Mamo is necessary for vasa expression in Drosophila. Here, we show that the truncated Mamo lacking the BTB/POZ domain (MamoAF) is a potent vasa activator. Overexpression of MamoAF was sufficient to induce vasa expression in both primordial germ cells and brain. Indeed, Mamo mRNA encoding a truncated Mamo isoform, which is similar to MamoAF, was predominantly expressed in primordial germ cells. The results of our genetic and biochemical studies showed that MamoAF, together with CBP, epigenetically activates vasa expression. Furthermore, MamoAF and the germline transcriptional activator OvoB exhibited synergy in activating vasa transcription. We propose that a Mamo-mediated network of epigenetic and transcriptional regulators activates vasa expression.
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Affiliation(s)
- Shoichi Nakamura
- Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe, 658-8501 Japan
- Graduate School of Natural Science, Konan University, Kobe, Japan
- Institute for Integrative Neurosciences, Konan University, Kobe, Japan
| | - Seiji Hira
- Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe, 658-8501 Japan
- Graduate School of Natural Science, Konan University, Kobe, Japan
- Institute for Integrative Neurosciences, Konan University, Kobe, Japan
- Division of Germ Cell Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, 444-8787 Japan
| | - Masato Fujiwara
- Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe, 658-8501 Japan
- Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Nasa Miyagata
- Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe, 658-8501 Japan
- Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Takuma Tsuji
- Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe, 658-8501 Japan
- Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Akane Kondo
- Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe, 658-8501 Japan
- Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Hiroshi Kimura
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503 Japan
| | - Yuko Shinozuka
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki, 305-8577 Japan
| | - Makoto Hayashi
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki, 305-8577 Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572 Japan
| | - Satoru Kobayashi
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki, 305-8577 Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572 Japan
| | - Masanori Mukai
- Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe, 658-8501 Japan
- Graduate School of Natural Science, Konan University, Kobe, Japan
- Institute for Integrative Neurosciences, Konan University, Kobe, Japan
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5
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Abstract
Gametogenesis represents the most dramatic cellular differentiation pathways in both female and male flies. At the genome level, meiosis ensures that diploid germ cells become haploid gametes. At the epigenome level, extensive changes are required to turn on and shut off gene expression in a precise spatiotemporally controlled manner. Research applying conventional molecular genetics and cell biology, in combination with rapidly advancing genomic tools have helped us to investigate (1) how germ cells maintain lineage specificity throughout their adult reproductive lifetime; (2) what molecular mechanisms ensure proper oogenesis and spermatogenesis, as well as protect genome integrity of the germline; (3) how signaling pathways contribute to germline-soma communication; and (4) if such communication is important. In this chapter, we highlight recent discoveries that have improved our understanding of these questions. On the other hand, restarting a new life cycle upon fertilization is a unique challenge faced by gametes, raising questions that involve intergenerational and transgenerational epigenetic inheritance. Therefore, we also discuss new developments that link changes during gametogenesis to early embryonic development-a rapidly growing field that promises to bring more understanding to some fundamental questions regarding metazoan development.
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6
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Jensen L, Grant JR, Laughinghouse HD, Katz LA. Assessing the effects of a sequestered germline on interdomain lateral gene transfer in Metazoa. Evolution 2016; 70:1322-33. [DOI: 10.1111/evo.12935] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/04/2016] [Accepted: 04/19/2016] [Indexed: 11/26/2022]
Affiliation(s)
- Lindy Jensen
- Department of Biological Sciences; Smith College; Northampton Massachusetts 01063
- Current Address: Department of Molecular and Integrative Physiology; University of Michigan; Ann Arbor Michigan 48109
| | - Jessica R. Grant
- Department of Biological Sciences; Smith College; Northampton Massachusetts 01063
| | | | - Laura A. Katz
- Department of Biological Sciences; Smith College; Northampton Massachusetts 01063
- Program in Organismic and Evolutionary Biology; University of Massachusetts; Amherst Massachusetts 01003
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7
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Heeren AM, He N, de Souza AF, Goercharn-Ramlal A, van Iperen L, Roost MS, Gomes Fernandes MM, van der Westerlaken LAJ, Chuva de Sousa Lopes SM. On the development of extragonadal and gonadal human germ cells. Biol Open 2016; 5:185-94. [PMID: 26834021 PMCID: PMC4823981 DOI: 10.1242/bio.013847] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Human germ cells originate in an extragonadal location and have to migrate to colonize the gonadal primordia at around seven weeks of gestation (W7, or five weeks post conception). Many germ cells are lost along the way and should enter apoptosis, but some escape and can give rise to extragonadal germ cell tumors. Due to the common somatic origin of gonads and adrenal cortex, we investigated whether ectopic germ cells were present in the human adrenals. Germ cells expressing DDX4 and/or POU5F1 were present in male and female human adrenals in the first and second trimester. However, in contrast to what has been described in mice, where 'adrenal' and 'ovarian' germ cells seem to enter meiosis in synchrony, we were unable to observe meiotic entry in human 'adrenal' germ cells until W22. By contrast, 'ovarian' germ cells at W22 showed a pronounced asynchronous meiotic entry. Interestingly, we observed that immature POU5F1+ germ cells in both first and second trimester ovaries still expressed the neural crest marker TUBB3, reminiscent of their migratory phase. Our findings highlight species-specific differences in early gametogenesis between mice and humans. We report the presence of a population of ectopic germ cells in the human adrenals during development.
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Affiliation(s)
- A Marijne Heeren
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Nannan He
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Aline F de Souza
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands Dept. of Veterinary Medicine, Faculty Animal Sciences and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte 225, 13630-000 SP Pirassununga, Brazil Dept. of Surgery, Faculty Veterinary Medicine and Animal Sciences, University of São Paulo, Av. Prof. Dr. Orlando Marques Paiva 87, 05508-270 SP São Paulo, Brazil
| | - Angelique Goercharn-Ramlal
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Liesbeth van Iperen
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Matthias S Roost
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Maria M Gomes Fernandes
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | | | - Susana M Chuva de Sousa Lopes
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
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8
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Jambor H, Mejstrik P, Tomancak P. Rapid Ovary Mass-Isolation (ROMi) to Obtain Large Quantities of Drosophila Egg Chambers for Fluorescent In Situ Hybridization. Methods Mol Biol 2016; 1478:253-262. [PMID: 27730587 DOI: 10.1007/978-1-4939-6371-3_15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Isolation of large quantities of tissue from organisms is essential for many techniques such as genome-wide screens and biochemistry. However, obtaining large quantities of tissues or cells is often the rate-limiting step when working in vivo. Here, we present a rapid method that allows the isolation of intact, single egg chambers at various developmental stages from ovaries of adult female Drosophila flies. The isolated egg chambers are amenable for a variety of procedures such as fluorescent in situ hybridization, RNA isolation, extract preparation, or immunostaining. Isolation of egg chambers from adult flies can be completed in 5 min and results, depending on the input amount of flies, in several milliliters of material. The isolated egg chambers are then further processed depending on the exact requirements of the subsequent application. We describe high-throughput in situ hybridization in 96-well plates as example application for the mass-isolated egg chambers.
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Affiliation(s)
- Helena Jambor
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307, Dresden, Germany.
| | - Pavel Mejstrik
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307, Dresden, Germany
| | - Pavel Tomancak
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307, Dresden, Germany.
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9
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Teng H, Sui X, Zhou C, Shen C, Yang Y, Zhang P, Guo X, Huo R. Fatty acid degradation plays an essential role in proliferation of mouse female primordial germ cells via the p53-dependent cell cycle regulation. Cell Cycle 2015; 15:425-31. [PMID: 26716399 DOI: 10.1080/15384101.2015.1127473] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Primordial germ cells (PGCs) are embryonic founders of germ cells that ultimately differentiate into oocytes and spermatogonia. Embryonic proliferation of PGCs starting from E11.5 ensures the presence of germ cells in adulthood, especially in female mammals whose total number of oocytes declines after this initial proliferation period. To better understand mechanisms underlying PGC proliferation in female mice, we constructed a proteome profile of female mouse gonads at E11.5. Subsequent KEGG pathway analysis of the 3,662 proteins profiled showed significant enrichment of pathways involved in fatty acid degradation. Further, the number of PGCs found in in vitro cultured fetal gonads significantly decreased with application of etomoxir, an inhibitor of the key rate-limiting enzyme of fatty acid degradation carnitine acyltransferase I (CPT1). Decrease in PGCs was further determined to be the result of reduced proliferation rather than apoptosis. The inhibition of fatty acid degradation by etomoxir has the potential to activate the Ca(2+)/CamKII/5'-adenosine monophosphate-activated protein kinase (AMPK) pathway; while as an upstream activator, activated AMPK can function as activator of p53 to induce cell cycle arrest. Thus, we detected the expressional level of AMPK, phosphorylated AMPK (P-AMPK), phosphorylated p53 (P-p53) and cyclin-dependent kinase inhibitor 1 (p21) by Western blots, the results showed increased expression of them after treatment with etomoxir, suggested the activation of p53 pathway was the reason for reduced proliferation of PGCs. Finally, the involvement of p53-dependent G1 cell cycle arrest in defective proliferation of PGCs was verified by rescue experiments. Our results demonstrate that fatty acid degradation plays an important role in proliferation of female PGCs via the p53-dependent cell cycle regulation.
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Affiliation(s)
- Hui Teng
- a State Key Laboratory of Reproductive Medicine , Department of Histology and Embryology, Nanjing Medical University , Nanjing , P.R. China
| | - Xuesong Sui
- a State Key Laboratory of Reproductive Medicine , Department of Histology and Embryology, Nanjing Medical University , Nanjing , P.R. China
| | - Cheng Zhou
- a State Key Laboratory of Reproductive Medicine , Department of Histology and Embryology, Nanjing Medical University , Nanjing , P.R. China
| | - Cong Shen
- a State Key Laboratory of Reproductive Medicine , Department of Histology and Embryology, Nanjing Medical University , Nanjing , P.R. China
| | - Ye Yang
- a State Key Laboratory of Reproductive Medicine , Department of Histology and Embryology, Nanjing Medical University , Nanjing , P.R. China
| | - Pang Zhang
- a State Key Laboratory of Reproductive Medicine , Department of Histology and Embryology, Nanjing Medical University , Nanjing , P.R. China
| | - Xuejiang Guo
- a State Key Laboratory of Reproductive Medicine , Department of Histology and Embryology, Nanjing Medical University , Nanjing , P.R. China
| | - Ran Huo
- a State Key Laboratory of Reproductive Medicine , Department of Histology and Embryology, Nanjing Medical University , Nanjing , P.R. China
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10
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Peterson JS, Timmons AK, Mondragon AA, McCall K. The End of the Beginning: Cell Death in the Germline. Curr Top Dev Biol 2015; 114:93-119. [PMID: 26431565 DOI: 10.1016/bs.ctdb.2015.07.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Programmed cell death occurs in the germline of many organisms, both as an essential part of development and throughout adult life. Germline cell death can be apoptotic or nonapoptotic, depending on the stimulus or stage of development. Here, we focus on the Drosophila ovary, which is a powerful model for studying diverse types of cell death. In Drosophila, the death of primordial germ cells occurs normally during embryonic development, and germline nurse cells are programmed to die during oocyte development in adult flies. Cell death of previtellogenic egg chambers in adults can also be induced by starvation or other environmental cues. Mid-oogenesis seems to be particularly sensitive to such cues and has been proposed to serve as a checkpoint to avoid the energetically expensive cost of egg production. After the germline dies in mid-oogenesis, the remnants are engulfed by an epithelial layer of follicle cells; thus, the fly ovary also serves as a highly tractable model for engulfment by epithelial cells. These examples of cell death in the fly ovary share many similarities to the types of cell death seen in the mammalian germline. Recent progress in elucidating the molecular mechanisms of cell death in the germline is discussed.
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Affiliation(s)
- Jeanne S Peterson
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Allison K Timmons
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | | | - Kimberly McCall
- Department of Biology, Boston University, Boston, Massachusetts, USA.
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11
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Pflanz R, Voigt A, Yakulov T, Jäckle H. Drosophila gene tao-1 encodes proteins with and without a Ste20 kinase domain that affect cytoskeletal architecture and cell migration differently. Open Biol 2015; 5:140161. [PMID: 25589578 PMCID: PMC4313371 DOI: 10.1098/rsob.140161] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Tao-1, the single representative of the Sterile 20 kinase subfamily in Drosophila, is best known for destabilizing microtubules at the actin-rich cortex, regulating the cytoskeletal architecture of cells. More recently, Tao-1 was shown to act in the Salvador–Warts–Hippo pathway by phosphorylating Hippo, regulating cell growth as well as cell polarity. Here, we show that tao-1 encodes two proteins, one with the Sterile 20 kinase domain (Tao-L) and one without it (Tao-S), and that they act in an antagonistic manner. Tao-L expression causes lamellipodia-like cell protrusions, whereas Tao-S expression results in filopodia-like structures that make cells stick to the surface they attach to. Ectopic Tao-1 expression in the anterior region of Drosophila embryos results in pole cell formation as normally observed at the posterior end. Tao-S expression causes primordial germ cells (PGCs) to adhere to the inner wall of the gut primordia and prevents proper transepithelial migration to the gonads. Conversely, RNAi knockdowns of Tao-1 cause disordered migration of PGCs out of the gut epithelium, their dispersal within the embryo and cell death. The results reveal a novel function of Tao-1 in cell migration, which is based on antagonistic activities of two proteins encoded by a single gene.
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Affiliation(s)
- Ralf Pflanz
- Abteilung Molekulare Entwicklungsbiologie, Max Planck Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Aaron Voigt
- Abteilung Molekulare Entwicklungsbiologie, Max Planck Institut für Biophysikalische Chemie, Göttingen, Germany Department of Neurology, University Medical Centre Aachen, Aachen, Germany
| | - Toma Yakulov
- Abteilung Molekulare Entwicklungsbiologie, Max Planck Institut für Biophysikalische Chemie, Göttingen, Germany Renal Division, University Hospital Freiburg, Freiburg, Germany
| | - Herbert Jäckle
- Abteilung Molekulare Entwicklungsbiologie, Max Planck Institut für Biophysikalische Chemie, Göttingen, Germany
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12
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Papagiannouli F, Lohmann I. Stage-specific control of stem cell niche architecture in the Drosophila testis by the posterior Hox gene Abd-B. Comput Struct Biotechnol J 2015; 13:122-30. [PMID: 25750700 PMCID: PMC4348433 DOI: 10.1016/j.csbj.2015.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 11/30/2022] Open
Abstract
A fundamental question in biology is how complex structures are maintained after their initial specification. We address this question by reviewing the role of the Hox gene Abd-B in Drosophila testis organogenesis, which proceeds through embryonic, larval and pupal stages to reach maturation in adult stages. The data presented in this review highlight a cell- and stage-specific function of Abd-B, since the mechanisms regulating stem cell niche positioning and architecture at different stages seem to be different despite the employment of similar factors. In addition to its described role in the male embryonic gonads, sustained activity of Abd-B in the pre-meiotic germline spermatocytes during larval stages is required to maintain the architecture of the stem cell niche by regulating βPS-integrin localization in the neighboring somatic cyst cells. Loss of Abd-B is associated with cell non-autonomous effects within the niche, leading to a dramatic reduction of pre-meiotic cell populations in adult testes. Identification of Abd-B target genes revealed that Abd-B mediates its effects by controlling the activity of the sevenless ligand Boss via its direct targets Src42A and Sec63. During adult stages, when testis morphogenesis is completed with the addition of the acto-myosin sheath originating from the genital disc, stem cell niche positioning and integrity are regulated by Abd-B activity in the acto-myosin sheath whereas integrin acts in an Abd-B independent way. It seems that the occurrence of new cell types and cell interactions in the course of testis organogenesis made it necessary to adapt the system to the new cellular conditions by reusing the same players for testis stem cell niche positioning in an alternative manner.
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Affiliation(s)
- Fani Papagiannouli
- Centre for Organismal Studies (COS) Heidelberg, Cell Networks - Cluster of Excellence, University of Heidelberg, D-69120, Germany
| | - Ingrid Lohmann
- Centre for Organismal Studies (COS) Heidelberg, Cell Networks - Cluster of Excellence, University of Heidelberg, D-69120, Germany
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13
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Abstract
The Drosophila melanogaster ovary has served as a popular and successful model for understanding a wide range of biological processes: stem cell function, germ cell development, meiosis, cell migration, morphogenesis, cell death, intercellular signaling, mRNA localization, and translational control. This review provides a brief introduction to Drosophila oogenesis, along with a survey of its diverse biological topics and the advanced genetic tools that continue to make this a popular developmental model system.
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Campanale JP, Gökirmak T, Espinoza JA, Oulhen N, Wessel GM, Hamdoun A. Migration of sea urchin primordial germ cells. Dev Dyn 2014; 243:917-27. [PMID: 24677545 PMCID: PMC4164171 DOI: 10.1002/dvdy.24133] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 03/23/2014] [Accepted: 03/24/2014] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Small micromeres are produced at the fifth cleavage of sea urchin development. They express markers of primordial germ cells (PGCs), and are required for the production of gametes. In most animals, PGCs migrate from sites of formation to the somatic gonad. Here, we investigated whether they also exhibit similar migratory behaviors using live-cell imaging of small micromere plasma membranes. RESULTS Early in gastrulation, small micromeres transition from non-motile epithelial cells, to motile quasi-mesenchymal cells. Late in gastrulation, at 43 hr post fertilization (HPF), they are embedded in the tip of the archenteron, but remain motile. From 43-49 HPF, they project numerous cortical blebs into the blastocoel, and filopodia that contact ectoderm. By 54 HPF, they begin moving in the plane of the blastoderm, often in a directed fashion, towards the coelomic pouches. Isolated small micromeres also produced blebs and filopodia. CONCLUSIONS Previous work suggested that passive translocation governs some of the movement of small micromeres during gastrulation. Here we show that small micromeres are motile cells that can traverse the archenteron, change position along the left-right axis, and migrate to coelomic pouches. These motility mechanisms are likely to play an important role in their left-right segregation.
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Affiliation(s)
- Joseph P. Campanale
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California
| | - Tufan Gökirmak
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California
| | - Jose A. Espinoza
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California
| | - Nathalie Oulhen
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island
| | - Gary M. Wessel
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island
| | - Amro Hamdoun
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California
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Yang JR, Ruan S, Zhang J. Determinative developmental cell lineages are robust to cell deaths. PLoS Genet 2014; 10:e1004501. [PMID: 25058586 PMCID: PMC4110091 DOI: 10.1371/journal.pgen.1004501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 05/24/2014] [Indexed: 11/18/2022] Open
Abstract
All forms of life are confronted with environmental and genetic perturbations, making phenotypic robustness an important characteristic of life. Although development has long been viewed as a key component of phenotypic robustness, the underlying mechanism is unclear. Here we report that the determinative developmental cell lineages of two protostomes and one deuterostome are structured such that the resulting cellular compositions of the organisms are only modestly affected by cell deaths. Several features of the cell lineages, including their shallowness, topology, early ontogenic appearances of rare cells, and non-clonality of most cell types, underlie the robustness. Simple simulations of cell lineage evolution demonstrate the possibility that the observed robustness arose as an adaptation in the face of random cell deaths in development. These results reveal general organizing principles of determinative developmental cell lineages and a conceptually new mechanism of phenotypic robustness, both of which have important implications for development and evolution.
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Affiliation(s)
- Jian-Rong Yang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Shuxiang Ruan
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
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Hu J, Sun S, Guo M, Song H. Use of antagonists and morpholinos in loss-of-function analyses: estrogen receptor ESR2a mediates the effects of 17alpha-ethinylestradiol on primordial germ cell distribution in zebrafish. Reprod Biol Endocrinol 2014; 12:40. [PMID: 24886565 PMCID: PMC4038371 DOI: 10.1186/1477-7827-12-40] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 05/10/2014] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Various chemicals released into the aquatic environment adversely affect the reproductive system of fish, particularly by changing gonad structure and function. 17alpha-ethinylestradiol (EE2) is a potent environmental estrogen that disrupts sexual differentiation and normal reproduction in fish. Previous studies have shown that exposure to endocrine-disrupting chemicals (EDCs) disrupts the migration of primordial germ cells (PGCs) in zebrafish. METHODS To investigate the effects of EE2 exposure on PGC migration, zebrafish embryos were injected with gfp-nanos mRNA to label PGCs and subsequently exposed to different concentrations of EE2. Typical estrogen receptor antagonist treatment and morpholino knockdown experiments were used to identify functional estrogen receptors that mediate the effects of EE2. RESULTS The migration of PGCs was disrupted after exposure to high concentrations of EE2 (1 mirog/L). Loss-of-function analyses were performed for estrogen receptor ESR1, ESR2a, and ESR2b, and only loss of ESR2a resulted in a decreased number of ectopic PGCs following exposure to 1 mirog/L EE2. CONCLUSIONS EE2 exposure disrupts PGC migration and distribution, and this effect is mediated through the estrogen receptor ESR2a.
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Affiliation(s)
- Jingying Hu
- Department of Biochemistry and Molecular Biology, Shanghai Medical School and Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University, Shanghai 200032, PR China
| | - Shaoyang Sun
- Department of Biochemistry and Molecular Biology, Shanghai Medical School and Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University, Shanghai 200032, PR China
| | - Meng Guo
- Department of Biochemistry and Molecular Biology, Shanghai Medical School and Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University, Shanghai 200032, PR China
| | - Houyan Song
- Department of Biochemistry and Molecular Biology, Shanghai Medical School and Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University, Shanghai 200032, PR China
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Three-step method for proliferation and differentiation of human embryonic stem cell (hESC)-derived male germ cells. PLoS One 2014; 9:e90454. [PMID: 24690677 PMCID: PMC3972183 DOI: 10.1371/journal.pone.0090454] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 02/03/2014] [Indexed: 12/26/2022] Open
Abstract
The low efficiency of differentiation into male germ cell (GC)-like cells and haploid germ cells from human embryonic stem cells (hESCs) reflects the culture method employed in the two-dimensional (2D)-microenvironment. In this study, we applied a three-step media and calcium alginate-based 3D-culture system for enhancing the differentiation of hESCs into male germ stem cell (GSC)-like cells and haploid germ cells. In the first step, embryoid bodies (EBs) were derived from hESCs cultured in EB medium for 3 days and re-cultured for 4 additional days in EB medium with BMP4 and RA to specify GSC-like cells. In the second step, the resultant cells were cultured in GC-proliferation medium for 7 days. The GSC-like cells were then propagated after selection using GFR-α1 and were further cultured in GC-proliferation medium for 3 weeks. In the final step, a 3D-co-culture system using calcium alginate encapsulation and testicular somatic cells was applied to induce differentiation into haploid germ cells, and a culture containing approximately 3% male haploid germ cells was obtained after 2 weeks of culture. These results demonstrated that this culture system could be used to efficiently induce GSC-like cells in an EB population and to promote the differentiation of ESCs into haploid male germ cells.
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18
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Zheng QS, Wang XN, Wen Q, Zhang Y, Chen SR, Zhang J, Li XX, Sha RN, Hu ZY, Gao F, Liu YX. Wt1 deficiency causes undifferentiated spermatogonia accumulation and meiotic progression disruption in neonatal mice. Reproduction 2014; 147:45-52. [DOI: 10.1530/rep-13-0299] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Spermatogenesis is a complex process involving the regulation of multiple cell types. As the only somatic cell type in the seminiferous tubules, Sertoli cells are essential for spermatogenesis throughout the spermatogenic cycle. The Wilms tumor gene, Wt1, is specifically expressed in the Sertoli cells of the mouse testes. In this study, we demonstrated that Wt1 is required for germ cell differentiation in the developing mouse testes. At 10 days post partum, Wt1-deficient testes exhibited clear meiotic arrest and undifferentiated spermatogonia accumulation in the seminiferous tubules. In addition, the expression of claudin11, a marker and indispensable component of Sertoli cell integrity, was impaired in Wt1−/flox; Cre-ERTM testes. This observation was confirmed in in vitro testis cultures. However, the basal membrane of the seminiferous tubules in Wt1-deficient testes was not affected. Based on these findings, we propose that Sertoli cells' status is affected in Wt1-deficient mice, resulting in spermatogenesis failure.
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Chen SR, Zheng QS, Zhang Y, Gao F, Liu YX. Disruption of genital ridge development causes aberrant primordial germ cell proliferation but does not affect their directional migration. BMC Biol 2013; 11:22. [PMID: 23497137 PMCID: PMC3652777 DOI: 10.1186/1741-7007-11-22] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 03/05/2013] [Indexed: 11/13/2022] Open
Abstract
Background The directional migration and the following development of primordial germ cells (PGCs) during gonad formation are key steps for germline development. It has been proposed that the interaction between germ cells and genital ridge (GR) somatic cells plays essential roles in this process. However, the in vivo functional requirements of GR somatic cells in germ cell development are largely unknown. Results Wt1 mutation (Wt1R394W/R394W) results in GR agenesis through mitotic arrest of coelomic epitheliums. In this study, we employed the GR-deficient mouse model, Wt1R394W/R394W, to investigate the roles of GR somatic cells in PGC migration and proliferation. We found that the number of PGCs was dramatically reduced in GR-deficient embryos at embryonic day (E) 11.5 and E12.5 due to decreased proliferation of PGCs, involving low levels of BMP signaling. In contrast, the germ cells in Wt1R394W/R394W embryos were still mitotically active at E13.5, while all the germ cells in control embryos underwent mitotic arrest at this stage. Strikingly, the directional migration of PGCs was not affected by the absence of GR somatic cells. Most of the PGCs reached the mesenchyme under the coelomic epithelium at E10.5 and no ectopic PGCs were noted in GR-deficient embryos. However, the precise positioning of PGCs was disrupted. Conclusions Our work provides in vivo evidence that the proliferation of germ cells is precisely regulated by GR somatic cells during different stages of gonad development. GR somatic cells are probably dispensable for the directional migration of PGCs, but they are required for precise positioning of PGCs at the final step of migration.
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Affiliation(s)
- Su-Ren Chen
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing, 100101, China
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20
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Return to the hematopoietic stem cell origin. CELL REGENERATION 2012; 1:9. [PMID: 25408872 PMCID: PMC4230910 DOI: 10.1186/2045-9769-1-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 11/26/2012] [Indexed: 12/18/2022]
Abstract
Studying embryonic hematopoiesis is complicated by diversity of its locations in the constantly changing anatomy and by the mobility of blood cell precursors. Embryonic hematopoietic progenitors are identified in traditional in vivo and in vitro cell potential assays. Profound epigenetic plasticity of mammalian embryonic cells combined with significant inductive capacity of the potential assays suggest that our understanding of hematopoietic ontogenesis is substantially distorted. Non-invasive in vivo cell tracing methodology offers a better insight into complex processes of blood cell specification. In contrast to the widely accepted view based on the cell potential assays, the genetic tracing approach identified the yolk sac as the source of adult hematopoietic stem cell lineage. Realistic knowledge of the blood origin is critical for safe and efficient recapitulation of hematopoietic development in culture.
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Papagiannouli F, Lohmann I. Shaping the niche: lessons from the Drosophila testis and other model systems. Biotechnol J 2012; 7:723-36. [PMID: 22488937 DOI: 10.1002/biot.201100352] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 01/31/2012] [Accepted: 02/27/2012] [Indexed: 11/12/2022]
Abstract
Stem cells are fascinating, as they supply the cells that construct our adult bodies and replenish, as we age, worn out, damaged, and diseased tissues. Stem cell regulation relies on intrinsic signals but also on inputs emanating from the neighbouring niche. The Drosophila testis provides an excellent system for studying such processes. Although recent advances have uncovered several signalling, cytoskeletal and other factors affecting niche homeostasis and testis differentiation, many aspects of niche regulation and maintenance remain unsolved. In this review, we discuss aspects of niche establishment and integrity not yet fully understood and we compare it to the current knowledge in other model systems such as vertebrates and plants. We also address specific questions on stem cell maintenance and niche regulation in the Drosophila testis under the control of Hox genes. Finally, we provide insights on the striking functional conservation of homologous genes in plants and animals and their respective stem cell niches. Elucidating conserved mechanisms of stem cell control in both lineages could reveal the importance underlying this conservation and justify the evolutionary pressure to adapt homologous molecules for performing the same task.
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Affiliation(s)
- Fani Papagiannouli
- Centre for Organismal Studies (COS) Heidelberg and CellNetworks - Cluster of Excellence, Heidelberg, Germany.
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22
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Abstract
Specialized microenvironments called niches help maintain stem cells in an undifferentiated and self-renewing state. The existence of niches has long been predicted from mammalian studies, but identifying stem cells in their native environments in vivo has remained a challenge in most vertebrates. Many of the mechanistic insights into how niches regulate stem cell maintenance have been obtained using invertebrate models such as Drosophila. Here, we focus on the Drosophila ovarian germline stem cell niche and review recent studies that have begun to reveal how intricate crosstalk between various signaling pathways regulates stem cell maintenance, how the extracellular matrix modulates the signaling output of the niche and how epigenetic programming influences cell development and function both inside and outside the niche to ensure proper tissue homeostasis. These insights will probably inform the study of mammalian niches and how their malfunction contributes to human disease.
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23
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Bakhrat A, Pritchett T, Peretz G, McCall K, Abdu U. Drosophila Chk2 and p53 proteins induce stage-specific cell death independently during oogenesis. Apoptosis 2011; 15:1425-34. [PMID: 20838898 DOI: 10.1007/s10495-010-0539-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
In Drosophila, the checkpoint protein-2 kinase (DmChk2) and its downstream effector protein, Dmp53, are required for DNA damage-mediated cell cycle arrest, DNA repair and apoptosis. In this study we focus on understanding the function of these two apoptosis inducing factors during ovarian development. We found that expression of Dmp53, but not DmChk2, led to loss of ovarian stem cells. We demonstrate that expression of DmChk2, but not Dmp53, induced mid-oogenesis cell death. DmChk2 induced cell death was not suppressed by Dmp53 mutant, revealing for the first time that in Drosophila, over-expression of DmChk2 can induce cell death which is independent of Dmp53. We found that over-expression of caspase inhibitors such as DIAP1, p35 and p49 did not suppress DmChk2- and Dmp53-induced cell death. Thus, our study reveals stage-specific effects of Dmp53 and DmChk2 in oogenesis. Moreover, our results demonstrate that although DmChk2 and Dmp53 affect different stages of ovarian development, loss of ovarian stem cells by p53 expression and mid-oogenesis cell death induced by DmChk2 do not require caspase activity.
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Affiliation(s)
- Anna Bakhrat
- Department of Life Sciences, Ben-Gurion University, 84105 Beer-Sheva, Israel
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24
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Abstract
During embryonic development in Drosophila, rodents, and other organisms, primordial germ cells (PGCs) migrate from their points of origin to the nascent gonads, where they give rise to germ line stem cells. Receptor tyrosine kinase (RTK) activity is required for normal migration of primordial germ cells in both Drosophila and rodents. In this chapter, we discuss in vivo as well as in vitro methods which have been used to elucidate the role of the RTK Torso in Drosophila germ cell migration. Included are protocols for embryo collection, fixation, and immunostaining; the dominant female sterile technique; in vitro culture and observation of PGCs; pole cell transplantation; and labeling of pole cells for in vivo observation.
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25
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Takahashi-Nakaguchi A, Hiraoka T, Iwabuchi K. An ultrastructural study of polyembryonic parasitoid embryo and host embryo cell interactions. J Morphol 2010; 271:750-8. [PMID: 20217899 DOI: 10.1002/jmor.10831] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The morula-stage embryo of the polyembryonic egg-larval parasitoid Copidosoma floridanum forms outside the host embryo and secondarily invades the host body. Electron microscopic analyses of cellular interactions between the extraembryonic syncytium of the parasitic morula and the host embryonic epithelial cells showed that morula penetration into the host embryo did not cause obvious damage to the host cells, except for the abrasion of the embryonic cuticle. Epithelial cells of the host embryo extended microvilli toward the invading C. floridanum morula and also adjacent host cells in the same way. Shortly after settlement of the morula within the host body cavity, gap junctions and adherens junctions with host cells were formed. The morula was then surrounded by a cyst comprised of host cells into which host tracheoles were invaginated.
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Affiliation(s)
- Azusa Takahashi-Nakaguchi
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
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26
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Richardson BE, Lehmann R. Mechanisms guiding primordial germ cell migration: strategies from different organisms. Nat Rev Mol Cell Biol 2010; 11:37-49. [PMID: 20027186 PMCID: PMC4521894 DOI: 10.1038/nrm2815] [Citation(s) in RCA: 328] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The regulated migration of cells is essential for development and tissue homeostasis, and aberrant cell migration can lead to an impaired immune response and the progression of cancer. Primordial germ cells (PGCs), precursors to sperm and eggs, have to migrate across the embryo to reach somatic gonadal precursors, where they carry out their function. Studies of model organisms have revealed that, despite important differences, several features of PGC migration are conserved. PGCs require an intrinsic motility programme and external guidance cues to survive and successfully migrate. Proper guidance involves both attractive and repulsive cues and is mediated by protein and lipid signalling.
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Affiliation(s)
- Brian E Richardson
- Howard Hughes Medical Institute, Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York University, New York, 10016, USA
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Analysis of SDF-1/CXCR4 signaling in primordial germ cell migration and survival or differentiation in Xenopus laevis. Mech Dev 2009; 127:146-58. [PMID: 19770040 DOI: 10.1016/j.mod.2009.09.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 09/10/2009] [Accepted: 09/14/2009] [Indexed: 01/08/2023]
Abstract
Directional migration of primordial germ cells (PGCs) toward future gonads is a common feature in many animals. In zebrafish, mouse and chicken, SDF-1/CXCR4 chemokine signaling has been shown to have an important role in PGC migration. In Xenopus, SDF-1 is expressed in several regions in embryos including dorsal mesoderm, the target region that PGCs migrate to. CXCR4 is known to be expressed in PGCs. This relationship is consistent with that of more well-known animals. Here, we present experiments that examine whether chemokine signaling is involved in PGC migration of Xenopus. We investigate: (1) Whether injection of antisense morpholino oligos (MOs) for CXCR4 mRNA into vegetal blastomere containing the germ plasm or the precursor of PGCs disturbs the migration of PGCs? (2) Whether injection of exogenous CXCR4 mRNA together with MOs can restore the knockdown phenotype? (3) Whether the migratory behavior of PGCs is disturbed by the specific expression of mutant CXCR4 mRNA or SDF-1 mRNA in PGCs? We find that the knockdown of CXCR4 or the expression of mutant CXCR4 in PGCs leads to a decrease in the PGC number of the genital ridges, and that the ectopic expression of SDF-1 in PGCs leads to a decrease in the PGC number of the genital ridges and an increase in the ectopic PGC number. These results suggest that SDF-1/CXCR4 chemokine signaling is involved in the migration and survival or in the differentiation of PGCs in Xenopus.
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28
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Affiliation(s)
- Rebecca Bastock
- Wellcome/CR-UK Gurdon Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
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29
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Gregory L, Came PJ, Brown S. Stem cell regulation by JAK/STAT signaling in Drosophila. Semin Cell Dev Biol 2008; 19:407-13. [PMID: 18603010 DOI: 10.1016/j.semcdb.2008.06.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Accepted: 06/12/2008] [Indexed: 11/16/2022]
Abstract
Stem cells have become one of the "buzz" topics in the last decade or so. One of the best systems to study adult stem cells in vivo is in the model organism, Drosophila melanogaster. One hundred years of genetic analysis, a sequenced and highly annotated genome and genomics makes this a difficult organism to avoid. The JAK/STAT pathway has been shown to regulate stem cells during haematopoiesis and gametogenesis in Drosophila. In this review we cover the current literature and contrast each group of stem cells with respect to JAK/STAT signaling.
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Affiliation(s)
- Lorna Gregory
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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30
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Fan L, Moon J, Wong TT, Crodian J, Collodi P. Zebrafish primordial germ cell cultures derived from vasa::RFP transgenic embryos. Stem Cells Dev 2008; 17:585-97. [PMID: 18576915 PMCID: PMC2741329 DOI: 10.1089/scd.2007.0178] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Accepted: 10/26/2007] [Indexed: 11/12/2022] Open
Abstract
Although embryonic germ (EG) cell-mediated gene transfer has been successful in the mouse for more than a decade, this approach is limited in other species due to the difficulty of isolating the small numbers of progenitors of germ cell lineage (PGCs) from early-stage embryos and the lack of information on the in vitro culture requirements of the cells. In this study, methods were established for the culture of PGCs obtained from zebrafish embryos. Transgenic embryos that express the red fluorescent protein (RFP) under the control of the PGC-specific vasa promoter were used, making it possible to isolate pure populations of PGCs by fluorescence-activated cell sorting (FACS) and to optimize the culture conditions by counting the number of fluorescent PGC colonies produced in different media. Cultures initiated from 26-somite-stage embryos contained the highest percentage of PGCs that proliferated in vitro to generate colonies. The effect of growth factors, including Kit ligand a and b (Kitlga and Kitlgb) and stromal cell-derived factor 1a and 1b (Sdf-1a and Sdf-1b), on PGC proliferation was studied. Optimal in vitro growth and survival of the zebrafish PGCs was achieved when recombinant Kitlga and Sdf-1b were added to the culture medium through transfected feeder cells, resulting in a doubling of the number of PGC colonies. Results from RT-PCR and in situ hybridization analysis demonstrated that PGCs maintained in culture expressed the kita receptor, even though receptor expression was not detected in PGCs isolated by FACS directly from dissociated embryos. In optimal growth conditions, the PGCs continued to proliferate for at least 4 months in culture. The capacity to establish long-term PGC cultures from zebrafish will make it possible to conduct in vitro studies of germ cell differentiation and EG cell pluripotency in this model species and may be valuable for the development of a cell-mediated gene transfer approach.
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Affiliation(s)
- Lianchun Fan
- Eli Lilly & Company, Indianapolis, IN 46221, USA.
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31
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Wingless signaling initiates mitosis of primordial germ cells during development in Drosophila. Mech Dev 2008; 125:498-507. [DOI: 10.1016/j.mod.2008.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2007] [Revised: 12/13/2007] [Accepted: 01/08/2008] [Indexed: 11/24/2022]
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Camara N, Whitworth C, Van Doren M. The creation of sexual dimorphism in the Drosophila soma. Curr Top Dev Biol 2008; 83:65-107. [PMID: 19118664 DOI: 10.1016/s0070-2153(08)00403-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Animals have evolved a fascinating array of mechanisms for conducting sexual reproduction. These include producing the sex-specific gametes, as well as mechanisms for attracting a mate, courting a mate, and getting the gametes together. These processes require that males and females take on dramatically different forms (sexual dimorphism). Here, we will explore the problem of how sex is determined in Drosophila, and pay particular attention to how information about sexual identity is used to instruct males and females to develop differently. Along the way, we will highlight new work that challenges some of the traditional views about sex determination. In Drosophila, it is commonly thought that every cell decides its own sex based on its sex chromosome constitution (XX vs. XY). However, we now know that many cell types undergo nonautonomous sex determination, where they are told what sex to be through signals from surrounding cells, independent of their own chromosomal content. Further, it now appears that not all cells even "know" their sex, since key members of the sex determination pathway are not expressed in all cells. Thus, our understanding of how sex is determined, and how sexual identity is used to create sexual dimorphism, has changed considerably.
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Affiliation(s)
- Nicole Camara
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
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33
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Yamada Y, Davis KD, Coffman CR. Programmed cell death of primordial germ cells in Drosophila is regulated by p53 and the Outsiders monocarboxylate transporter. Development 2007; 135:207-16. [PMID: 18057102 DOI: 10.1242/dev.010389] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Primordial germ cell development uses programmed cell death to remove abnormal, misplaced or excess cells. Precise control of this process is essential to maintain the continuity and integrity of the germline, and to prevent germ cells from colonizing locations other than the gonads. Through careful analyses of primordial germ cell distribution in developing Drosophila melanogaster embryos, we show that normal germ cell development involves extensive programmed cell death during stages 10-12 of embryogenesis. This germ cell death is mediated by Drosophila p53 (p53). Mutations in p53 result in excess primordial germ cells that are ectopic to the gonads. Initial movements of the germ cells appear normal, and wild-type numbers of germ cells populate the gonads, indicating that p53 is required for germ cell death, but not migration. To our knowledge, this is the first report of a loss-of-function phenotype for Drosophila p53 in a non-sensitized background. The p53 phenotype is remarkably similar to that of outsiders (out) mutants. Here, we show that the out gene encodes a putative monocarboxylate transporter. Mutations in p53 and out show nonallelic noncomplementation. Interestingly, overexpression of p53 in primordial germ cells of out mutant embryos partially suppresses the out germ cell death phenotype, suggesting that p53 functions in germ cells either downstream of out or in a closely linked pathway. These findings inform models in which signaling between p53 and cellular metabolism are integrated to regulate programmed cell death decisions.
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Affiliation(s)
- Yukiko Yamada
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA 50011-3260, USA
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Tanentzapf G, Devenport D, Godt D, Brown NH. Integrin-dependent anchoring of a stem-cell niche. Nat Cell Biol 2007; 9:1413-8. [PMID: 17982446 PMCID: PMC3529653 DOI: 10.1038/ncb1660] [Citation(s) in RCA: 176] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 09/27/2007] [Indexed: 12/26/2022]
Abstract
Interactions between stem cells and their surrounding microenvironment, or niche, are critical for the establishment and maintenance of stem-cell properties. The adult Drosophila testis contains a morphologically discrete stem-cell niche, the 'hub'. The small cluster of non-dividing, somatic hub cells at the anterior tip of the fly testis is contacted by the germline stem cells (GSCs), which retain their stem-cell character through the direct association with the hub. Here we show that integrin-mediated adhesion is important for maintaining the correct position of embryonic hub cells during gonad morphogenesis. The misplaced hub in integrin-deficient embryos directs the orientation of cell divisions in the presumptive GSCs, a hallmark of the active germline stem-cell niche. A decrease in integrin-mediated adhesion in adult testes, which resulted in a loss of the hub and the stem-cell population, revealed the importance of hub-cell anchoring. Finally, we show that an extracellular matrix (ECM) is present around the gonad during late embryogenesis and that this ECM is defective in integrin-deficient gonads. On the basis of our data, we propose that integrins are required for the attachment of the hub cells to the ECM, which is essential for maintaining the stem-cell niche.
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Affiliation(s)
- Guy Tanentzapf
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 1QN, UK.
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35
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Greenfeld CR, Pepling ME, Babus JK, Furth PA, Flaws JA. BAX regulates follicular endowment in mice. Reproduction 2007; 133:865-76. [PMID: 17616717 DOI: 10.1530/rep-06-0270] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It is believed that the endowment of primordial follicles in mammalian ovaries is finite. Once follicles are depleted, infertility ensues. Thus, the size of the initial endowment has consequences for fertility and reproductive longevity. Follicular endowment is comprised of various processes that culminate with the incorporation of meiosis-arrested oocytes into primordial follicles. Apoptosis is prominent during follicular endowment, and apoptosis regulatory genes are involved in its regulation. Conflicting data exist with regard to the role of the proapoptotic Bcl-2 associated X protein (BAX) in follicular endowment. Therefore, we investigated the role of BAX during follicular endowment in embryonic and neonatal ovaries. We found that BAX is involved in regulating follicular endowment in mice. Deletion ofBaxyields increased oocyte numbers in embryonic ovaries and increased follicle numbers in neonatal ovaries when compared with wild-type ovaries. Increased follicular endowment inBax−/−ovaries is not due to enhanced germ cell viability. Further, it is not due to an increased primordial germ cell (PGC) allotment, a delay in the onset of meiosis, or altered proliferative activity of oogonia. Instead, our data suggest that the regulatory activity of BAX in follicular endowment likely occurs during PGC migration, prior to PGC colonization of the gonad.
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Affiliation(s)
- Chuck R Greenfeld
- Department of Physiology, University of Maryland, Baltimore, MD 21201, USA
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36
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Sato K, Hayashi Y, Ninomiya Y, Shigenobu S, Arita K, Mukai M, Kobayashi S. Maternal Nanos represses hid/skl-dependent apoptosis to maintain the germ line in Drosophila embryos. Proc Natl Acad Sci U S A 2007; 104:7455-60. [PMID: 17449640 PMCID: PMC1854842 DOI: 10.1073/pnas.0610052104] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Nanos (Nos) is an evolutionarily conserved protein essential for the survival of primordial germ cells. In Drosophila, maternal Nos partitions into pole cells and suppresses apoptosis to permit proper germ-line development. However, how this critical event is regulated by Nos has remained elusive. Here, we report that Nos represses apoptosis of pole cells by suppressing translation of head involution defective (hid), a member of the RHG gene family that is required for Caspase activation. In addition, we demonstrate that hid acts in concert with another RHG gene, sickle (skl), to induce apoptosis. Expression of skl is induced in pole cells by maternal tao-1, a ste20-like serine/threonine kinase. Tao-1-dependent skl expression is required to potentiate hid activity. However, skl expression is largely suppressed in normal pole cells. Once the pole cells lack maternal Nos, Tao-1-dependent skl expression is fully activated, suggesting that skl expression is also restricted by Nos. These findings provide the first evidence that the germ line is maintained through the regulated expression of RHG genes.
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Affiliation(s)
- Kimihiro Sato
- *Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan
| | - Yoshiki Hayashi
- *Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan
| | - Yuichi Ninomiya
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1241, Japan; and
| | - Shuji Shigenobu
- *Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan
| | - Kayo Arita
- *Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan
| | - Masanori Mukai
- *Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan
| | - Satoru Kobayashi
- *Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Honcho, Kawaguchi 332-0012, Japan
- To whom correspondence should be addressed. E-mail:
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Tsukamoto H, Takizawa T, Takamori K, Ogawa H, Araki Y. Genomic organization and structure of the 5'-flanking region of the TEX101 gene: alternative promoter usage and splicing generate transcript variants with distinct 5'-untranslated region. Mol Reprod Dev 2007; 74:154-62. [PMID: 16941676 DOI: 10.1002/mrd.20584] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A novel germ cell-specific antigen, TEX101 (TES101-reactive protein), was previously identified using a monoclonal antibody directed against mouse testicular cells. TEX101 is specifically located on the plasma membrane of germ cells, and its expression in gonadal organs is sexually dimorphic. To understand the fundamental mechanism directing gene expression, the genomic organization of TEX101 was studied. The gene consists of five translated exons (exons 2-6) and three 5'-untranslated exons (exon 1a, 1b, and 1c), respectively. TEX101 forms three major transcripts classified by usage of the three 5'-untranslated exons. One form of TEX101 mRNA is transcribed from exon 1c and spliced to the common acceptor site in exon 2. In the second form of the transcript, exon 1a is spliced to exon 1b and exon 2 in a sequential manner. Splicing from exon 1a to exon 2, arises the third form of transcript. Reverse Transcription (RT)-polymerase chain reaction (PCR) analysis demonstrated differential expression pattern of the TEX101 transcripts between testis and ovary. Whereas the expression of transcript-1 is constitutive in male and female gonads, the transcript-2 and -3 are detected only after starting of the spermatogenesis. Luciferase reporter assays using GC-2spd(ts) cells, a cell line from immortalized mouse testicular cells, showed that the 5'-flanking sequence of exon 1c has higher promoter activity than exon 1a. Deletion analysis of the chimeric structures indicated that sequences essential to gene expression are present on the 5'-flanking region between -3186 and +14, where the cluster of five CAAT boxes is located. Taken together, these findings should facilitate an understanding of the regulation of TEX101 expression during gametogenesis.
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Affiliation(s)
- Hiroki Tsukamoto
- Institute for Environmental & Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Urayasu City, Chiba, Japan
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Pepling ME, Wilhelm JE, O'Hara AL, Gephardt GW, Spradling AC. Mouse oocytes within germ cell cysts and primordial follicles contain a Balbiani body. Proc Natl Acad Sci U S A 2006; 104:187-92. [PMID: 17189423 PMCID: PMC1765432 DOI: 10.1073/pnas.0609923104] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The Balbiani body or mitochondrial cloud is a large distinctive organelle aggregate found in developing oocytes of many species, but its presence in the mouse has been controversial. Using confocal and electron microscopy, we report that a Balbiani body does arise in mouse neonatal germline cysts and oocytes of primordial follicles but disperses as follicles begin to grow. The mouse Balbiani body contains a core of Golgi elements surrounded by mitochondria and associated endoplasmic reticulum. Because of their stage specificity and perinuclear rather than spherical distribution, these clustered Balbiani body mitochondria may have been missed previously. The Balbiani body also contains Trailer hitch, a widely conserved member of a protein complex that associates with endoplasmic reticulum/Golgi-like vesicles and transports specific RNAs during Drosophila oogenesis. Our results provide evidence that mouse oocytes develop using molecular and developmental mechanisms widely conserved throughout the animal kingdom.
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Affiliation(s)
- Melissa E. Pepling
- *Department of Biology, Syracuse University, Syracuse, NY 13244; and
- To whom correspondence may be addressed. E-mail:
or
| | - James E. Wilhelm
- Department of Embryology/Howard Hughes Medical Institute, Carnegie Institution of Washington, Baltimore, MD 21210
| | - Ashley L. O'Hara
- *Department of Biology, Syracuse University, Syracuse, NY 13244; and
| | - Grant W. Gephardt
- *Department of Biology, Syracuse University, Syracuse, NY 13244; and
| | - Allan C. Spradling
- Department of Embryology/Howard Hughes Medical Institute, Carnegie Institution of Washington, Baltimore, MD 21210
- To whom correspondence may be addressed. E-mail:
or
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Abstract
The basic concepts of the molecular machinery that mediates cell migration have been gleaned from cell culture systems. However, the three-dimensional environment within an organism presents migrating cells with a much greater challenge. They must move between and among other cells while interpreting multiple attractive and repulsive cues to choose their proper path. They must coordinate their cell adhesion with their surroundings and know when to start and stop moving. New insights into the control of these remaining mysteries have emerged from genetic dissection and live imaging of germ cell migration in Drosophila, zebrafish, and mouse embryos. In this review, we first describe germ cell migration in cellular and mechanistic detail in these different model systems. We then compare these systems to highlight the emerging principles. Finally, we contrast the migration of germ cells with that of immune and cancer cells to outline the conserved and different mechanisms.
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Affiliation(s)
- Prabhat S Kunwar
- Howard Hughes Medical Institute, Developmental Genetics Program, Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, New York 10016-6402, USA.
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40
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Montell DJ. The social lives of migrating cells in Drosophila. Curr Opin Genet Dev 2006; 16:374-83. [PMID: 16797177 DOI: 10.1016/j.gde.2006.06.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 06/09/2006] [Indexed: 11/29/2022]
Abstract
Studies of cell migration in Drosophila are yielding insights into the complex interactions migrating cells have with each other and with the cells in their environment. Intriguing links between factors that promote cell migration and those that control cell survival have been reported recently. For example, migrating germ cells compete with the surrounding somatic tissue for the substrate of the lipid phosphate phosphatases encoded by the genes Wunen and Wunen2. Germ cells take up the dephosphorylated lipid and require it for their survival. In addition, the secreted growth factors called PVFs, previously thought to guide the migrations of hemocytes in the embryo, were found to function instead predominantly as survival factors. And in border cells, DIAP1 and Dronc, two proteins known mainly for their ability to regulate cell death, were found to control cell migration.
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Affiliation(s)
- Denise J Montell
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
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41
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Abstract
The gene of germ cell-less (gcl) has been shown to be important in early differentiation of germ cells in Drosophila. Although the gcl homologue genes have been identified in some organisms, there is little data on the expression pattern and functional analysis of the gcl gene in zebrafish. In this research, real-time quantitative reverse transcription-polymerase chain reaction showed that the level of gcl mRNA expression rapidly decreases from the 4-cell stage to the sphere stage at which it reaches a minimum, gradually increases from the 50%-epiboly stage, and then remains stable during the posterior stages. Results of in situ hybridization indicated that the transcripts of zebrafish gcl are evenly distributed in all blastomeres from the 2-cell stage to the blastula period, different from that of vasa, nonas1 and dead end mRNA, and condense into some clusters of cells located along the blastoderm margin from the gastrulation period. During subsequent development, the transcripts are segregated as subcellular clumps to a small number of cells that would migrate to the position of the gonad in the dorsal side. In the adult, gcl mRNA was widely expressed in developing germ cells of both ovary and testis. These data suggest that zebrafish gcl have potentially important roles in the formation of primordial germ cells.
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Affiliation(s)
- Wenyan Li
- Key Laboratory of MOE for Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, Hubei, China
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42
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Brown S, Zeidler MP, Hombría JECG. JAK/STAT signalling in Drosophila controls cell motility during germ cell migration. Dev Dyn 2006; 235:958-66. [PMID: 16477645 DOI: 10.1002/dvdy.20709] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The gonad is formed from two populations of cells originating at different locations: the primordial germ cells (PGCs), giving rise to either sperm or oocytes, and the somatic gonadal mesoderm precursors (SGPs), which support development of the gametes. Following the PGCs' migration during gastrulation, these two populations meet, forming the immature gonad. We present evidence that during embryonic development, the PGCs require the canonical JAK/STAT signalling cascade to migrate efficiently towards the SGPs. Loss of function for any element of the JAK/STAT pathway causes frequent germ cell mislocalisation. We have found that wild-type germ cells produce filopodia while they migrate through the mesoderm towards the gonad. Our observations suggest that PGCs use filopodia to migrate and to keep contact with each other. Interestingly, activation of the JAK/STAT pathway is required for these filopodia to form, and ectopic JAK/STAT activation enhances their formation.
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Affiliation(s)
- Stephen Brown
- Faculty of Life Sciences, University of Manchester, C.1247 Michael Smith Building, Oxford Road, Manchester M13 9PT, U.K.
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43
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Tsai HH, Macklin WB, Miller RH. Netrin-1 is required for the normal development of spinal cord oligodendrocytes. J Neurosci 2006; 26:1913-22. [PMID: 16481423 PMCID: PMC6674920 DOI: 10.1523/jneurosci.3571-05.2006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Successful CNS myelination is dependent on the correct localization of oligodendrocytes and their interactions with adjacent axons. In the spinal cord, oligodendrocyte precursors originate at the ventral midline and subsequently migrate to the white matter where they mature. In vitro studies suggest this dispersal is mediated by the guidance molecule netrin-1. Here, we show that in the spinal cord of netrin-1 mutant mice, oligodendrocyte precursors failed to disperse from the ventral midline as a consequence of a lack of polarization and directional migration. The lack of netrin-1 also resulted in an overall reduction of oligodendrocyte lineage cells that was independent of the failure of initial dispersal. Oligodendrocyte precursors injected into presumptive white matter underwent extensive radial migration and expansion in wild-type but not netrin-1 mutant hosts. These data indicate that netrin-1 is crucial for both the initial dispersal of spinal cord oligodendrocyte precursors and their subsequent development in the presumptive white matter.
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44
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Mathews WR, Ong D, Milutinovich AB, Van Doren M. Zinc transport activity of Fear of Intimacy is essential for proper gonad morphogenesis and DE-cadherin expression. Development 2006; 133:1143-53. [PMID: 16481356 DOI: 10.1242/dev.02256] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Embryonic gonad formation involves intimate contact between germ cells and specialized somatic cells along with the complex morphogenetic movements necessary to create proper gonad architecture. Previously, we have shown that gonad formation in Drosophila requires the homophilic cell-adhesion molecule Drosophila E-cadherin (DE-cadherin), and also Fear of Intimacy (FOI), which is required for stable accumulation of DE-cadherin protein in the gonad. Here, we present an in vivo structure-function analysis of FOI that strongly indicates that zinc transport activity of FOI is essential for gonad development. Mutant forms of FOI that are defective for zinc transport also fail to rescue morphogenesis and DE-cadherin expression in the gonad. We further show that expression of DE-cadherin in the gonad is regulated post-transcriptionally and that foi affects this post-transcriptional control. Expression of DE-cadherin from a ubiquitous(tubulin) promoter still results in gonad-specific accumulation of DE-cadherin, which is strongly reduced in foi mutants. This work indicates that zinc is a crucial regulator of developmental processes and can affect DE-cadherin expression on multiple levels.
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Affiliation(s)
- Wendy R Mathews
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
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45
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Hsouna A, Watson DK, Hsu T. Developmental expression pattern of D-ets4, the Drosophila homologue of human Pdef. Gene Expr Patterns 2006; 5:285-9. [PMID: 15567727 DOI: 10.1016/j.modgep.2004.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2004] [Revised: 07/05/2004] [Accepted: 07/06/2004] [Indexed: 11/18/2022]
Abstract
Primordial germ cells (PGCs) are the first cells specified in many organisms. In Drosophila, as in mammals, PGCs are formed at the posterior end outside of the embryonic proper. They are brought into the gut during gastrulation and then actively migrate through the gut epithelium into the mesoderm. They attach to the future gonadal mesoderm and coalesce, forming the gonads. Control of this migratory process is not yet completely understood. D-ets4 and its mammalian homologue Pdef are members of the evolutionarily conserved Ets family of transcription factors. Pdef has been shown to down-regulate the invasive and migratory potential of breast tumors. Our results show that the Drosophila D-ets4 protein is specifically expressed in PGCs before the onset of migration and is lost in the migratory and post-migratory PGCs. We also show that D-ets4 is not involved in other migratory events such as border cell migration during oogenesis. It is, however, expressed strongly in the pre-stage 10 oocyte nuclei and modestly in larval tissues such as imaginal discs and salivary glands, but not in the brain.
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Affiliation(s)
- Anita Hsouna
- Department of Pathology and Laboratory Medicine, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
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46
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Villaescusa JC, Allard P, Carminati E, Kontogiannea M, Talarico D, Blasi F, Farookhi R, Verrotti AC. Clast4, the murine homologue of human eIF4E-Transporter, is highly expressed in developing oocytes and post-translationally modified at meiotic maturation. Gene 2005; 367:101-9. [PMID: 16343815 DOI: 10.1016/j.gene.2005.09.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Revised: 09/23/2005] [Accepted: 09/23/2005] [Indexed: 10/25/2022]
Abstract
In metazoans, translational regulation of a set of maternal mRNAs directs oocyte maturation and early embryogenesis. These transcripts are often kept dormant until their products are spatially and temporally required in development. The interaction between general translation factors (i.e. eIF4E) and their specific interactors influences translation initiation. A search of the protein database for a mouse homologue of the Drosophila Cup protein, a translational repressor during female germ-line development, identified the product of the Clast4 gene. In this report, we show that Clast4 mRNA and protein are highly expressed within the cytoplasm of growing oocytes. The Clast4 protein is stable during this developmental window and post-translationally modified by phosphorylation upon oocyte meiotic maturation. Additionally, we show that Clast4 and eIF4E directly interact by means of a canonical and functional eIF4E-binding motif. Our results suggest that Clast4, similar to Drosophila Cup, may act at the translational level during murine female germ-line development.
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47
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Sigal Y, McDERMOTT M, Morris A. Integral membrane lipid phosphatases/phosphotransferases: common structure and diverse functions. Biochem J 2005; 387:281-93. [PMID: 15801912 PMCID: PMC1134956 DOI: 10.1042/bj20041771] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Phospholipids and sphingolipids play critical roles in signal transduction, intracellular membrane trafficking, and control of cell growth and survival. We discuss recent progress in the identification and characterization of a family of integral membrane proteins with central roles in bioactive lipid metabolism and signalling. These five groups of homologous proteins, which we collectively term LPTs (lipid phosphatases/phosphotransferases), are characterized by a core domain containing six transmembrane-spanning alpha-helices connected by extramembrane loops, two of which interact to form the catalytic site. LPT family members are localized to all major membrane compartments of the cell. The transmembrane topology of these proteins places their active site facing the lumen of endomembrane compartments or the extracellular face of the plasma membrane. Sequence conservation between the active site of the LPPs (lipid phosphate phosphatases), SPPs (sphingosine phosphate phosphatases) and the recently identified SMSs (sphingomyelin synthases) with vanadium-dependent fungal oxidases provides a framework for understanding their common catalytic mechanism. LPPs hydrolyse LPA (lysophosphatidic acid), S1P (sphingosine 1-phosphate) and structurally-related substrates. Although LPPs can dephosphorylate intracellularly generated substrates to control intracellular lipid metabolism and signalling, their best understood function is to regulate cell surface receptor-mediated signalling by LPA and S1P by inactivating these lipids at the plasma membrane or in the extracellular space. SPPs are intracellularly localized S1P-selective phosphatases, with key roles in the pathways of sphingolipid metabolism linked to control of cell growth and survival. The SMS enzymes catalyse the interconversion of phosphatidylcholine and ceramide with sphingomyelin and diacylglycerol, suggesting a pivotal role in both housekeeping lipid synthesis and regulation of bioactive lipid mediators. The remaining members of the LPT family, the LPR/PRGs (lipid phosphatase-related proteins/plasticity-related genes) and CSS2s (type 2 candidate sphingomyelin synthases), are presently much less well studied. These two groups include proteins that lack critical amino acids within the catalytic site, and could therefore not use the conserved LPT reaction mechanism to catalyse lipid phosphatase or phosphotransferase reactions. In this review, we discuss recent ideas about their possible biological activities and functions, which appear to involve regulation of cellular morphology and, possibly, lipid metabolism and signalling in the nuclear envelope.
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Affiliation(s)
- Yury J. Sigal
- Department of Cell and Developmental Biology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7090, U.S.A
| | - Mark I. McDERMOTT
- Department of Cell and Developmental Biology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7090, U.S.A
| | - Andrew J. Morris
- Department of Cell and Developmental Biology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7090, U.S.A
- To whom correspondence should be addressed (email )
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48
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Amikura R, Sato K, Kobayashi S. Role of mitochondrial ribosome-dependent translation in germline formation in Drosophila embryos. Mech Dev 2005; 122:1087-93. [PMID: 16125913 DOI: 10.1016/j.mod.2005.06.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Revised: 03/29/2005] [Accepted: 06/13/2005] [Indexed: 11/25/2022]
Abstract
In Drosophila, mitochondrially encoded ribosomal RNAs (mtrRNAs) form mitochondrial-type ribosomes on the polar granules, distinctive organelles of the germ plasm. Since a reduction in the amount of mtrRNA results in the failure of embryos to produce germline progenitors, or pole cells, it has been proposed that translation by mitochondrial-type ribosomes is required for germline formation. Here, we report that injection of kasugamycin (KA) and chloramphenicol (CH), inhibitors for prokaryotic-type translation, disrupted pole cell formation in early embryos. The number of mitochondrial-type ribosomes on polar granules was significantly decreased by KA treatment, as shown by electron microscopy. In contrast, ribosomes in the mitochondria and mitochondrial activity were unaffected by KA and CH. We further found that injection of KA and CH impairs production of Germ cell-less (Gcl) protein, which is required for pole cell formation. The above observations suggest that mitochondrial-type translation is required for pole cell formation, and Gcl is a probable candidate for the protein produced by this translation system.
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Affiliation(s)
- Reiko Amikura
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787, Japan
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49
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Fuhrmann G. [Derivation of germ cells from mouse embryonic stem cells in culture]. ACTA ACUST UNITED AC 2005; 33:813-8. [PMID: 16154375 DOI: 10.1016/j.gyobfe.2005.07.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Accepted: 07/15/2005] [Indexed: 11/28/2022]
Abstract
Mouse embryonic stem cells derive from the inner cell mass of the blastocyst and give rise to the three primitive embryonic layers, which later will form all the different tissue types of an adult. Embryonic stem cells are thus defined as totipotent cells. In vitro, these cells can give rise to all the somatic cells. Different laboratories have now shown that cultured embryonic stem cells can also differentiate into germline cells. By using the transcription factor Oct-4 as a tool for the visualization of germ cells, it has been shown the derivation of oocytes from mouse embryonic stem cells. These works should contribute to various areas, including therapeutic cloning which associates nuclear transfer and selective production of a specific cell type.
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Affiliation(s)
- G Fuhrmann
- Laboratoire de pharmacologie et physicochimie des interactions cellulaires et moléculaires, UMR 7034, CNRS, faculté de pharmacie, 74, route du Rhin, 67401 Illkirch-Graffenstaden, France.
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Kobayashi S, Sato K, Hayashi Y. The Role of Mitochondrial rRNAs and Nanos Protein in Germline Formation in Drosophila Embryos. Zoolog Sci 2005; 22:943-54. [PMID: 16219975 DOI: 10.2108/zsj.22.943] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Germ cells, represented by male sperm and female eggs, are specialized cells that transmit genetic material from one generation to the next during sexual reproduction. The mechanism by which multicellular organisms achieve the proper separation of germ cells and somatic cells is one of the longest standing issues in developmental biology. In many animal groups, a specialized portion of the egg cytoplasm, or germ plasm, is inherited by the cell lineage that gives rise to the germ cells (germline). Germ plasm contains maternal factors that are sufficient for germline formation. In the fruit fly, Drosophila, germ plasm is referred to as polar plasm and is distinguished histologically by the presence of polar granules, which act as a repository for the maternal factors required for germline formation. Molecular screens have so far identified several of these factors that are enriched in the polar plasm. This article focuses on the molecular functions of two such factors in Drosophila, mitochondrial ribosomal RNAs and Nanos protein, which are required for the formation and differentiation of the germline progenitors, respectively.
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Affiliation(s)
- Satoru Kobayashi
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, Myodaiji, Okazaki, Japan.
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