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Spichal M, Heestand B, Billmyre KK, Frenk S, Mello CC, Ahmed S. Germ granule dysfunction is a hallmark and mirror of Piwi mutant sterility. Nat Commun 2021; 12:1420. [PMID: 33658512 PMCID: PMC7930041 DOI: 10.1038/s41467-021-21635-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 01/29/2021] [Indexed: 01/31/2023] Open
Abstract
In several species, Piwi/piRNA genome silencing defects cause immediate sterility that correlates with transposon expression and transposon-induced genomic instability. In C. elegans, mutations in the Piwi-related gene (prg-1) and other piRNA deficient mutants cause a transgenerational decline in fertility over a period of several generations. Here we show that the sterility of late generation piRNA mutants correlates poorly with increases in DNA damage signaling. Instead, sterile individuals consistently exhibit altered perinuclear germ granules. We show that disruption of germ granules does not activate transposon expression but induces multiple phenotypes found in sterile prg-1 pathway mutants. Furthermore, loss of the germ granule component pgl-1 enhances prg-1 mutant infertility. Environmental restoration of germ granule function for sterile pgl-1 mutants restores their fertility. We propose that Piwi mutant sterility is a reproductive arrest phenotype that is characterized by perturbed germ granule structure and is phenocopied by germ granule dysfunction, independent of genomic instability.
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Affiliation(s)
- Maya Spichal
- grid.410711.20000 0001 1034 1720Department of Genetics, University of North Carolina, Chapel Hill, NC USA ,grid.410711.20000 0001 1034 1720Department of Biology, University of North Carolina, Chapel Hill, NC USA ,grid.168645.80000 0001 0742 0364RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA USA
| | - Bree Heestand
- grid.410711.20000 0001 1034 1720Department of Genetics, University of North Carolina, Chapel Hill, NC USA ,grid.410711.20000 0001 1034 1720Department of Biology, University of North Carolina, Chapel Hill, NC USA
| | - Katherine Kretovich Billmyre
- grid.410711.20000 0001 1034 1720Department of Genetics, University of North Carolina, Chapel Hill, NC USA ,grid.410711.20000 0001 1034 1720Department of Biology, University of North Carolina, Chapel Hill, NC USA ,grid.250820.d0000 0000 9420 1591Present Address: Stowers Institute for Medical Research, Kansas City, MO USA
| | - Stephen Frenk
- grid.410711.20000 0001 1034 1720Department of Genetics, University of North Carolina, Chapel Hill, NC USA ,grid.410711.20000 0001 1034 1720Department of Biology, University of North Carolina, Chapel Hill, NC USA ,Present Address: Achilles Therapeutics Limited, London, UK
| | - Craig C. Mello
- grid.168645.80000 0001 0742 0364RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA USA ,grid.413575.10000 0001 2167 1581Howard Hughes Medical Institute, Worcester, MA USA
| | - Shawn Ahmed
- grid.410711.20000 0001 1034 1720Department of Genetics, University of North Carolina, Chapel Hill, NC USA ,grid.410711.20000 0001 1034 1720Department of Biology, University of North Carolina, Chapel Hill, NC USA ,grid.410711.20000 0001 1034 1720Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC USA
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Min H, Lee YU, Shim YH, Kawasaki I. Autophagy of germ-granule components, PGL-1 and PGL-3, contributes to DNA damage-induced germ cell apoptosis in C. elegans. PLoS Genet 2019; 15:e1008150. [PMID: 31125345 PMCID: PMC6534287 DOI: 10.1371/journal.pgen.1008150] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 04/23/2019] [Indexed: 12/19/2022] Open
Abstract
Germ granules, termed P granules in nematode C. elegans, are the germline-specific cytoplasmic structures widely observed from worms to humans. P granules are known to have critical functions for postembryonic germline development likely through regulating RNA metabolism. They are localized at the perinuclear region of germ cells during most of the developmental stages. However, the biological significance of this specific localization remains elusive. PGL-1 and PGL-3, the defining components of P granules, were shown to be lost from the perinuclear region prior to germ cell apoptosis. Furthermore, this loss was shown to be significantly enhanced upon DNA damage. Here, we show that the removal of PGL-1 and PGL-3 from the perinuclear region following UV-induced DNA damage is significantly reduced in autophagy mutants. Autophagy was previously shown to be required for DNA damage-induced germ cell apoptosis. We show that the apoptosis defect of autophagy mutants is bypassed by depletion of pgl-1 or pgl-3. These findings are consistent with time-lapse observations of LGG-1 foci formation, showing that autophagy is activated following UV irradiation and that maximal accumulation of LGG-1 foci occurs before PGL-1 removal. We also show that some of the autophagy genes are transcriptionally activated following UV irradiation by CEP-1, the worm p53-like protein. Taken together, our results indicate that autophagy is required to remove the major P granule components, PGL-1 and PGL-3, and that their removal is required for the full induction of DNA damage-induced germ cell apoptosis. Our study contributes to a better understanding of germ cell apoptosis, a process that leads to the elimination of the vast majority of germ cells in various animals from worms to mammals.
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Affiliation(s)
- Hyemin Min
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Yong-Uk Lee
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Yhong-Hee Shim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Ichiro Kawasaki
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea
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Cui F, Ma N, Han X, Chen N, Xi Y, Yuan W, Xu Y, Han J, Xu X, Tu Y. Effects of 60Co γ Irradiation on the Reproductive Function of Caenorhabditis elegans. Dose Response 2019; 17:1559325818820981. [PMID: 30733651 PMCID: PMC6343448 DOI: 10.1177/1559325818820981] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/07/2018] [Accepted: 11/18/2018] [Indexed: 12/15/2022] Open
Abstract
The effects of ionizing radiation on the reproductive system have always been a matter of great interest. Both artificial and naturally occurring ionizing radiation can directly or indirectly affect the reproductive system via the introduction of DNA single-strand and double-strand breaks, the excitation of water molecules, and the generation of free radicals. In order to quantitatively investigate the effects of ionizing radiation on reproductive function, 60Co γ irradiation was applied on a model organism, Caenorhabditis elegans (C. elegans). The egg-laying and embryo-hatching activities were observed for the parent (F0) and the first 2 progeny (F1 and F2) generations. The incidence rate of ovipositor malformation was also recorded. Acridine orange was used to detect the number of apoptotic germ cells. With the above metrics, the effects of 60Co γ irradiation on the reproductive function of C. elegans were systematically evaluated. The results showed that the postirradiation egg-laying and embryo-hatching activities of the F0 generation were increasingly suppressed by increasing doses of 60Co γ irradiation. Those of the F1 generation showed a trend toward recovery although also suppressed by the radiation to the F0 generation compared with the control. Those activities were restored to normal or near-normal levels for the F2 generation. The incidence rate of ovipositor malformation was greatly increased by 60Co γ irradiation according to radiation doses. Gamma irradiation by 60Co also substantially induced germ cell apoptosis, and the apoptosis rate increased with increasing radiation doses. Therefore, 60Co γ irradiation affects the reproductive function of C. elegans. The suppression on its reproductive function increases with increasing radiation doses. The reproductive functions of progeny generations are also affected and weakened.
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Affiliation(s)
- Fengmei Cui
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Nan Ma
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Xiaojing Han
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Department of Hematology and Oncology, The First Affiliated Hospital of Suzhou University, Suzhou, China
| | - Na Chen
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Yue Xi
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Weiye Yuan
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Yufan Xu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Jianfang Han
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Xiaoyan Xu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Yu Tu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
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