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Shabtai R, Tzur YB. Male-specific roles of lincRNA in C. elegans fertility. Front Cell Dev Biol 2023; 11:1115605. [PMID: 37035238 PMCID: PMC10076526 DOI: 10.3389/fcell.2023.1115605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 03/08/2023] [Indexed: 04/11/2023] Open
Abstract
The testis is the mammalian tissue with the highest expression levels of long intergenic non-coding RNAs (lincRNAs). However, most in vivo models have not found significant reductions in male fertility when highly expressed lincRNA genes were removed. This suggests that certain lincRNAs may act redundantly or lack functional roles. In the genome of the nematode Caenorhabditis elegans, there is an order of magnitude fewer lincRNA genes than in mammals. This characteristic lowers the potential for redundancy, making it an ideal model to test these possibilities. We identified five highly and dynamically expressed lincRNAs in male C. elegans gonads and quantified the fertility of worm strains in which these genes were removed. In contrast to the hermaphrodites of deletion strains, which exhibited no significant reductions in broods, smaller brood sizes were observed in the progeny of males of three of the lincRNA deleted strains. This demonstrates reduced male fertility in worms with those genes removed. Interestingly, reduced brood size was statistically significant only in the last days of egg laying in two of these strains. This suggests the effect is due to early deterioration and aging of the transferred sperm. We detected a mild increase in embryonic lethality in only one of the strains, supporting the possibility that these lincRNAs do not affect fertility through critical roles in essential meiotic processes. Together our results indicate a sexually dimorphic outcome on fertility when lincRNA are removed and show that, unlike mammals, individual lincRNAs in C. elegans do play significant roles in male fertility.
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2
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Cao W, Tran C, Archer SK, Gopal S, Pocock R. Functional recovery of the germ line following splicing collapse. Cell Death Differ 2022; 29:772-787. [PMID: 34663906 PMCID: PMC8991207 DOI: 10.1038/s41418-021-00891-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 09/30/2021] [Accepted: 10/04/2021] [Indexed: 11/09/2022] Open
Abstract
Splicing introns from precursor-messenger RNA (pre-mRNA) transcripts is essential for translating functional proteins. Here, we report that the previously uncharacterized Caenorhabditis elegans protein MOG-7 acts as a pre-mRNA splicing factor. Depleting MOG-7 from the C. elegans germ line causes intron retention in most germline-expressed genes, impeding the germ cell cycle, and causing defects in nuclear morphology, germ cell identity and sterility. Despite the deleterious consequences caused by MOG-7 loss, the adult germ line can functionally recover to produce viable and fertile progeny when MOG-7 is restored. Germline recovery is dependent on a burst of apoptosis that likely clears defective germ cells, and viable gametes generated from the proliferation of germ cells in the progenitor zone. Together, these findings reveal that MOG-7 is essential for germ cell development, and that the germ line can functionally recover after a collapse in RNA splicing.
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Affiliation(s)
- Wei Cao
- grid.1002.30000 0004 1936 7857Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC 3800 Australia
| | - Christopher Tran
- grid.1002.30000 0004 1936 7857Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC 3800 Australia
| | - Stuart K. Archer
- grid.1002.30000 0004 1936 7857Monash Bioinformatics Platform, Monash University, Melbourne, VIC 3800 Australia
| | - Sandeep Gopal
- grid.1002.30000 0004 1936 7857Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC 3800 Australia
| | - Roger Pocock
- grid.1002.30000 0004 1936 7857Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC 3800 Australia
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3
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Kar FM, Hochwagen A. Phospho-Regulation of Meiotic Prophase. Front Cell Dev Biol 2021; 9:667073. [PMID: 33928091 PMCID: PMC8076904 DOI: 10.3389/fcell.2021.667073] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 03/22/2021] [Indexed: 12/12/2022] Open
Abstract
Germ cells undergoing meiosis rely on an intricate network of surveillance mechanisms that govern the production of euploid gametes for successful sexual reproduction. These surveillance mechanisms are particularly crucial during meiotic prophase, when cells execute a highly orchestrated program of chromosome morphogenesis and recombination, which must be integrated with the meiotic cell division machinery to ensure the safe execution of meiosis. Dynamic protein phosphorylation, controlled by kinases and phosphatases, has emerged as one of the main signaling routes for providing readout and regulation of chromosomal and cellular behavior throughout meiotic prophase. In this review, we discuss common principles and provide detailed examples of how these phosphorylation events are employed to ensure faithful passage of chromosomes from one generation to the next.
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Affiliation(s)
- Funda M Kar
- Department of Biology, New York University, New York, NY, United States
| | - Andreas Hochwagen
- Department of Biology, New York University, New York, NY, United States
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4
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Hammerquist AM, Escorcia W, Curran SP. Maf1 regulates intracellular lipid homeostasis in response to DNA damage response activation. Mol Biol Cell 2021; 32:1086-1093. [PMID: 33788576 PMCID: PMC8351542 DOI: 10.1091/mbc.e20-06-0378] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Surveillance of DNA damage and maintenance of lipid metabolism are critical factors for general cellular homeostasis. We discovered that in response to DNA damage–inducing UV light exposure, intact Caenorhabditis elegans accumulate intracellular lipids in a dose-dependent manner. The increase in intracellular lipids in response to exposure to UV light utilizes mafr-1, a negative regulator of RNA polymerase III and the apical kinases atm-1 and atl-1 of the DNA damage response (DDR) pathway. In the absence of exposure to UV light, the genetic ablation of mafr-1 results in the activation of the DDR, including increased intracellular lipid accumulation, phosphorylation of ATM/ATR target proteins, and expression of the Bcl-2 homology region genes, egl-1 and ced-13. Taken together, our results reveal mafr-1 as a component the DDR pathway response to regulating lipid homeostasis following exposure to UV genotoxic stress.
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Affiliation(s)
- Amy M Hammerquist
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089.,Molecular and Computational Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089
| | - Wilber Escorcia
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089.,Department of Biology, Xavier University, Cincinnati, OH 45207
| | - Sean P Curran
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089.,Molecular and Computational Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089.,Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
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5
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Systematic analysis of long intergenic non-coding RNAs in C. elegans germline uncovers roles in somatic growth. RNA Biol 2020; 18:435-445. [PMID: 32892705 DOI: 10.1080/15476286.2020.1814549] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Long intergenic non-coding RNAs (lincRNAs) are transcripts longer than 200 nucleotides that are transcribed from non-coding loci yet undergo biosynthesis similar to coding mRNAs. The disproportional number of lincRNAs expressed in testes suggests that lincRNAs are important during gametogenesis, but experimental evidence has implicated very few lincRNAs in this process. We took advantage of the relatively limited number of lincRNAs in the genome of the nematode Caenorhabditis elegans to systematically analyse the functions of lincRNAs during meiosis. We deleted six lincRNA genes that are highly and dynamically expressed in the C. elegans gonad and tested the effects on central meiotic processes. Surprisingly, whereas the lincRNA deletions did not strongly impact fertility, germline apoptosis, crossovers, or synapsis, linc-4 was required for somatic growth. Slower growth was observed in linc-4-deletion mutants and in worms depleted of linc-4 using RNAi, indicating that linc-4 transcripts are required for this post-embryonic process. Unexpectedly, analysis of worms depleted of linc-4 in soma versus germline showed that the somatic role stems from linc-4 expression in germline cells. This unique feature suggests that some lincRNAs, like some small non-coding RNAs, are required for germ-soma interactions.
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6
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Achache H, Laurent L, Hecker-Mimoun Y, Ishtayeh H, Rappaport Y, Kroizer E, Colaiácovo MP, Tzur YB. Progression of Meiosis Is Coordinated by the Level and Location of MAPK Activation Via OGR-2 in Caenorhabditis elegans. Genetics 2019; 212:213-229. [PMID: 30867196 PMCID: PMC6499523 DOI: 10.1534/genetics.119.302080] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 03/07/2019] [Indexed: 02/07/2023] Open
Abstract
During meiosis, a series of evolutionarily conserved events allow for reductional chromosome division, which is required for sexual reproduction. Although individual meiotic processes have been extensively studied, we currently know far less about how meiosis is regulated and coordinated. In the Caenorhabditis elegans gonad, mitogen-activated protein kinase (MAPK) signaling drives oogenesis while undergoing spatial activation and deactivation waves. However, it is currently unclear how MAPK activation is governed and how it facilitates the progression of oogenesis. Here, we show that the oocyte and germline-related 2 (ogr-2) gene affects proper progression of oogenesis. Complete deletion of ogr-2 results in delayed meiotic entry and late spatial onset of double-strand break repair. Elevated levels of apoptosis are observed in this mutant, independent of the meiotic canonical checkpoints; however, they are dependent on the MAPK terminal member MPK-1/ERK. MPK-1 activation is elevated in diplotene in ogr-2 mutants and its aberrant spatial activation correlates with stages where meiotic progression defects are evident. Deletion of ogr-2 significantly reduces the expression of lip-1, a phosphatase reported to repress MPK-1, which is consistent with OGR-2 localization at chromatin in germ cells. We suggest that OGR-2 modulates the expression of lip-1 to promote the timely progression of meiosis through MPK-1 spatial deactivation.
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Affiliation(s)
- Hanna Achache
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Lévana Laurent
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Yaël Hecker-Mimoun
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Hasan Ishtayeh
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Yisrael Rappaport
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Eitan Kroizer
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | | | - Yonatan B Tzur
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
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7
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Tzur YB, Winter E, Gao J, Hashimshony T, Yanai I, Colaiácovo MP. Spatiotemporal Gene Expression Analysis of the Caenorhabditis elegans Germline Uncovers a Syncytial Expression Switch. Genetics 2018; 210:587-605. [PMID: 30093412 PMCID: PMC6216576 DOI: 10.1534/genetics.118.301315] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/03/2018] [Indexed: 11/18/2022] Open
Abstract
Developmental programs are executed by tightly controlled gene regulatory pathways. Here, we combined the unique sample retrieval capacity afforded by laser capture microscopy with analysis of mRNA abundance by CEL-Seq (cell expression by linear amplification and sequencing) to generate a spatiotemporal gene expression map of the Caenorhabditis elegans syncytial germline from adult hermaphrodites and males. We found that over 6000 genes exhibit spatiotemporally dynamic expression patterns throughout the hermaphrodite germline, with two dominant groups of genes exhibiting reciprocal shifts in expression at late pachytene during meiotic prophase I. We found a strong correlation between restricted spatiotemporal expression and known developmental and cellular processes, indicating that these gene expression changes may be an important driver of germ cell progression. Analysis of the male gonad revealed a shift in gene expression at early pachytene and upregulation of subsets of genes following the meiotic divisions, specifically in early and late spermatids, mostly transcribed from the X chromosome. We observed that while the X chromosome is silenced throughout the first half of the gonad, some genes escape this control and are highly expressed throughout the germline. Although we found a strong correlation between the expression of genes corresponding to CSR-1-interacting 22G-RNAs during germ cell progression, we also found that a large fraction of genes may bypass the need for CSR-1-mediated germline licensing. Taken together, these findings suggest the existence of mechanisms that enable a shift in gene expression during prophase I to promote germ cell progression.
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Affiliation(s)
- Yonatan B Tzur
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115
- Department of Genetics, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem 91904, Israel
| | - Eitan Winter
- Department of Biology, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Jinmin Gao
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115
| | - Tamar Hashimshony
- Department of Biology, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Itai Yanai
- Department of Biology, Technion - Israel Institute of Technology, Haifa 32000, Israel
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8
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King SD, Gray CF, Song L, Nechushtai R, Gumienny TL, Mittler R, Padilla PA. The cisd gene family regulates physiological germline apoptosis through ced-13 and the canonical cell death pathway in Caenorhabditis elegans. Cell Death Differ 2018; 26:162-178. [PMID: 29666474 PMCID: PMC6294797 DOI: 10.1038/s41418-018-0108-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 02/13/2018] [Accepted: 03/05/2018] [Indexed: 11/09/2022] Open
Abstract
Programmed cell death, which occurs through a conserved core molecular pathway, is important for fundamental developmental and homeostatic processes. The human iron-sulfur binding protein NAF-1/CISD2 binds to Bcl-2 and its disruption in cells leads to an increase in apoptosis. Other members of the CDGSH iron sulfur domain (CISD) family include mitoNEET/CISD1 and Miner2/CISD3. In humans, mutations in CISD2 result in Wolfram syndrome 2, a disease in which the patients display juvenile diabetes, neuropsychiatric disorders and defective platelet aggregation. The C. elegans genome contains three previously uncharacterized cisd genes that code for CISD-1, which has homology to mitoNEET/CISD1 and NAF-1/CISD2, and CISD-3.1 and CISD-3.2, both of which have homology to Miner2/CISD3. Disrupting the function of the cisd genes resulted in various germline abnormalities including distal tip cell migration defects and a significant increase in the number of cell corpses within the adult germline. This increased germ cell death is blocked by a gain-of-function mutation of the Bcl-2 homolog CED-9 and requires functional caspase CED-3 and the APAF-1 homolog CED-4. Furthermore, the increased germ cell death is facilitated by the pro-apoptotic, CED-9-binding protein CED-13, but not the related EGL-1 protein. This work is significant because it places the CISD family members as regulators of physiological germline programmed cell death acting through CED-13 and the core apoptotic machinery.
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Affiliation(s)
- Skylar D King
- Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
| | - Chipo F Gray
- Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
| | - Luhua Song
- Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
| | - Rachel Nechushtai
- Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram, Jerusalem, 91904, Israel
| | - Tina L Gumienny
- Department of Biology, Texas Woman's University, Denton, TX, 76204, USA
| | - Ron Mittler
- Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
| | - Pamela A Padilla
- Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA.
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9
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Turcotte CA, Sloat SA, Rigothi JA, Rosenkranse E, Northrup AL, Andrews NP, Checchi PM. Maintenance of Genome Integrity by Mi2 Homologs CHD-3 and LET-418 in Caenorhabditis elegans. Genetics 2018; 208:991-1007. [PMID: 29339410 PMCID: PMC5844346 DOI: 10.1534/genetics.118.300686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 01/10/2018] [Indexed: 02/06/2023] Open
Abstract
Meiotic recombination depends upon the tightly coordinated regulation of chromosome dynamics and is essential for the production of haploid gametes. Central to this process is the formation and repair of meiotic double-stranded breaks (DSBs), which must take place within the constraints of a specialized chromatin architecture. Here, we demonstrate a role for the nucleosome remodeling and deacetylase (NuRD) complex in orchestrating meiotic chromosome dynamics in Caenorhabditis elegans Our data reveal that the conserved Mi2 homologs Chromodomain helicase DNA-binding protein (CHD-3) and its paralog LET-418 facilitate meiotic progression by ensuring faithful repair of DSBs through homologous recombination. We discovered that loss of either CHD-3 or LET-418 results in elevated p53-dependent germ line apoptosis, which relies on the activation of the conserved checkpoint kinase CHK-1 Consistent with these findings, chd-3 and let-418 mutants produce a reduced number of offspring, indicating a role for Mi2 in forming viable gametes. When Mi2 function is compromised, persisting recombination intermediates are detected in late pachytene nuclei, indicating a failure in the timely repair of DSBs. Intriguingly, our data indicate that in Mi2 mutant germ lines, a subset of DSBs are repaired by nonhomologous end joining, which manifests as chromosomal fusions. We find that meiotic defects are exacerbated in Mi2 mutants lacking CKU-80, as evidenced by increased recombination intermediates, corpses, and defects in chromosomal integrity. Taken together, our findings support a model wherein the C. elegans Mi2 complex maintains genomic integrity through reinforcement of a chromatin landscape suitable for homology-driven repair mechanisms.
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Affiliation(s)
| | - Solomon A Sloat
- Department of Biology, Marist College, Poughkeepsie, New York 12601
| | - Julia A Rigothi
- Department of Biology, Marist College, Poughkeepsie, New York 12601
| | | | | | | | - Paula M Checchi
- Department of Biology, Marist College, Poughkeepsie, New York 12601
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10
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Ruan Q, Xu Y, Xu R, Wang J, Hua Y, Wang M, Duan J. The Adverse Effects of Triptolide on the Reproductive System of Caenorhabditis elegans: Oogenesis Impairment and Decreased Oocyte Quality. Int J Mol Sci 2017; 18:E464. [PMID: 28230788 PMCID: PMC5343997 DOI: 10.3390/ijms18020464] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 02/01/2017] [Accepted: 02/14/2017] [Indexed: 12/15/2022] Open
Abstract
Previous studies have revealed that Triptolide damages female reproductive capacity, but the mechanism is unclear. In this study, we used Caenorhabditis elegans to investigate the effects of Triptolide on the germline and explore its possible mechanisms. Our data show that exposure for 4 h to 50 and 100 mg/L Triptolide reduced C. elegans fertility, led to depletion and inactivation of spermatids with the changes in the expression levels of related genes, and increased the number of unfertilized oocytes through damaging chromosomes and DNA damage repair mechanisms. After 24 and 48 h of the 4 h exposure to 50 and 100 mg/L Triptolide, we observed shrink in distal tip cells, an increase in the number of apoptotic cells, a decrease in the number of mitotic germ cells and oocytes in diakinesis stage, and chromatin aggregates in -1 oocytes. Moreover, expression patterns of the genes associated with mitotic germ cell proliferation, apoptosis, and oocyte quality were altered after Triptolide exposure. Therefore, Triptolide may damage fertility of nematodes by hampering the development of oocytes at different developmental stages. Alterations in the expression patterns of genes involved in oocyte development may explain the corresponding changes in oocyte development in nematodes exposed to Triptolide.
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Affiliation(s)
- Qinli Ruan
- Center for Drug Safety Evaluation and Research, Nanjing University of Chinese Medicine, Nanjing 210023, China.
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing 210023, China.
| | - Yun Xu
- Center for Drug Safety Evaluation and Research, Nanjing University of Chinese Medicine, Nanjing 210023, China.
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing 210023, China.
| | - Rui Xu
- Center for Drug Safety Evaluation and Research, Nanjing University of Chinese Medicine, Nanjing 210023, China.
| | - Jiaying Wang
- Center for Drug Safety Evaluation and Research, Nanjing University of Chinese Medicine, Nanjing 210023, China.
| | - Yongqing Hua
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing 210023, China.
| | - Meng Wang
- Center for Drug Safety Evaluation and Research, Nanjing University of Chinese Medicine, Nanjing 210023, China.
| | - Jinao Duan
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing 210023, China.
- Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing University of Chinese Medicine, Nanjing 210023, China.
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