1
|
Hepatotoxicity and genotoxicity of gasoline fumes in albino rats. BENI-SUEF UNIVERSITY JOURNAL OF BASIC AND APPLIED SCIENCES 2017. [DOI: 10.1016/j.bjbas.2017.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
2
|
Singh SK, Yadav D, Lal RK, Gupta MM, Dhawan SS. Inducing mutations through γ-irradiation in seeds of Mucuna pruriens for developing high L-DOPA-yielding genotypes. Int J Radiat Biol 2016; 93:426-432. [PMID: 27897091 DOI: 10.1080/09553002.2016.1254832] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE To develop elite genotypes in Mucuna pruriens (L.) DC with high L-DOPA (L-3, 4 dihydroxyphenylalanine) yields, with non-itching characteristics and better adaptability by applying γ-irradiation. Molecular and chemical analysis was performed for screening based on specific characteristics desired for developing suitable genotypes. MATERIALS AND METHODS Developed, mutant populations were analyzed for L-DOPA % in seeds through TLC (thin layer chromatography), and the results obtained were validated with the HPLC (High performance liquid chromatography). The DNA (Deoxyribonucleic acid) was isolated from the leaf at the initial stage and used for DNA polymorphism. RNA (Ribonucleic acid) was isolated from the leaf during maturity and used for expression analysis. RESULTS The selected mutant T-I-7 showed 5.7% L-DOPA content compared to 3.18% of parent CIM-Ajar. The total polymorphism obtained was 57% with the molecular marker analysis. The gene expression analysis showed higher fold change expression of the dopadecarboxylase gene (DDC) in control compared to selected mutants (T-I-7, T-II-23, T-IV-9, T-VI-1). CONCLUSION DNA polymorphism was used for the screening of mutants for efficient screening at an early stage. TLC was found suitable for the large-scale comparative chemical analysis of L-DOPA. The expression profile of DDC clearly demonstrated the higher yields of L-DOPA in selected mutants developed by γ-irradiation in the seeds of the control.
Collapse
Affiliation(s)
- Susheel Kumar Singh
- a Council of Scientific and Industrial Research (CSIR), Central Institute of Medicinal and Aromatic Plants (CIMAP) , Lucknow , India
| | - Deepti Yadav
- a Council of Scientific and Industrial Research (CSIR), Central Institute of Medicinal and Aromatic Plants (CIMAP) , Lucknow , India
| | - Raj Kishori Lal
- a Council of Scientific and Industrial Research (CSIR), Central Institute of Medicinal and Aromatic Plants (CIMAP) , Lucknow , India
| | - Madan M Gupta
- a Council of Scientific and Industrial Research (CSIR), Central Institute of Medicinal and Aromatic Plants (CIMAP) , Lucknow , India
| | - Sunita Singh Dhawan
- a Council of Scientific and Industrial Research (CSIR), Central Institute of Medicinal and Aromatic Plants (CIMAP) , Lucknow , India
| |
Collapse
|
3
|
Abdou HM, Hassan MA. Protective role of omega-3 polyunsaturated fatty acid against lead acetate-induced toxicity in liver and kidney of female rats. BIOMED RESEARCH INTERNATIONAL 2014; 2014:435857. [PMID: 25045676 PMCID: PMC4086517 DOI: 10.1155/2014/435857] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 04/30/2014] [Accepted: 05/21/2014] [Indexed: 11/17/2022]
Abstract
The present study was conducted to investigate the protective role of Omega-3 polyunsaturated fatty acids against lead acetate-induced toxicity in liver and kidney of female rats. Animals were divided into four equal groups; group 1 served as control while groups 2 and 3 were treated orally with Omega-3 fatty acids at doses of 125 and 260 mg/kg body weight, respectively, for 10 days. These groups were also injected with lead acetate (25 mg/kg body weight) during the last 5 days. Group 4 was treated only with lead acetate for 5 days and served as positive control group. Lead acetate increased oxidative stress through an elevation in MDA associated with depletion in antioxidant enzymes activities in the tissues. Moreover, the elevation of serum enzymes activities (ALT, AST, ALP, and LDH) and the levels of urea and creatinine were estimated but total proteins were decreased. Also, lead acetate-treatment induced hyperlipidemia via increasing of lipid profiles associated with decline in HDL-c level. Significant changes of Hb, PCV, RBCs, PLT, and WBCs in group 4 were recorded. The biochemical alterations of lead acetate were confirmed by histopathological changes and DNA damage. The administration of Omega-3 provided significant protection against lead acetate toxicity.
Collapse
Affiliation(s)
- Heba M. Abdou
- Zoology Department, Faculty of Science, Alexandria University, Moharram Bey, Alexandria 21511, Egypt
| | - Mohamed A. Hassan
- Protein Research Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab, Alexandria 21934, Egypt
| |
Collapse
|
4
|
Little MP, Goodhead DT, Bridges BA, Bouffler SD. Evidence relevant to untargeted and transgenerational effects in the offspring of irradiated parents. Mutat Res 2013; 753:50-67. [PMID: 23648355 PMCID: PMC3737396 DOI: 10.1016/j.mrrev.2013.04.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 04/20/2013] [Accepted: 04/22/2013] [Indexed: 12/19/2022]
Abstract
In this article we review health effects in offspring of human populations exposed as a result of radiotherapy and some groups exposed to chemotherapy. We also assess risks in offspring of other radiation-exposed groups, in particular those of the Japanese atomic bomb survivors and occupationally and environmentally exposed groups. Experimental findings are also briefly surveyed. Animal and cellular studies tend to suggest that the irradiation of males, at least at high doses (mostly 1Gy and above), can lead to observable effects (including both genetic and epigenetic) in the somatic cells of their offspring over several generations that are not attributable to the inheritance of a simple mutation through the parental germline. However, studies of disease in the offspring of irradiated humans have not identified any effects on health. The available evidence therefore suggests that human health has not been significantly affected by transgenerational effects of radiation. It is possible that transgenerational effects are restricted to relatively short times post-exposure and in humans conception at short times after exposure is likely to be rare. Further research that may help resolve the apparent discrepancies between cellular/animal studies and studies of human health are outlined.
Collapse
Affiliation(s)
- Mark P Little
- Radiation Epidemiology Branch, National Cancer Institute, 9609 Medical Center Drive, MSC 9778, Bethesda, MD 20892-9778, USA.
| | | | - Bryn A Bridges
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK.
| | - Simon D Bouffler
- Centre for Radiation, Chemical and Environmental hazards, Public Health England, Chilton, Didcot OX11 0RQ, UK.
| |
Collapse
|
5
|
Mosesso P, Angeletti D, Pepe G, Pretti C, Nascetti G, Bellacima R, Cimmaruta R, Jha AN. The use of cyprinodont fish, Aphanius fasciatus, as a sentinel organism to detect complex genotoxic mixtures in the coastal lagoon ecosystem. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2012; 742:31-6. [DOI: 10.1016/j.mrgentox.2011.11.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 10/14/2011] [Accepted: 11/17/2011] [Indexed: 10/14/2022]
|
6
|
Hinton TG, Coughlin D, Yi Y, Glenn T, Zimbrick J. Reproductive Effects from Chronic, Multigenerational, Low Dose Rate Exposures to Radiation. RADIOBIOLOGY AND ENVIRONMENTAL SECURITY 2012. [DOI: 10.1007/978-94-007-1939-2_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
|
7
|
Tsyusko O, Yi Y, Coughlin D, Main D, Podolsky R, Hinton TG, Glenn TC. Radiation-induced untargeted germline mutations in Japanese medaka. Comp Biochem Physiol C Toxicol Pharmacol 2007; 145:103-10. [PMID: 17045552 DOI: 10.1016/j.cbpc.2006.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 08/22/2006] [Accepted: 08/26/2006] [Indexed: 11/24/2022]
Abstract
Radiation has been shown to increase mutation frequencies at tandem repeat loci by indirect interactions of radiation with DNA. We studied germline mutations in chronically exposed Japanese medaka (Oryzias latipes) using microsatellite loci. After screening 26 randomly selected loci among unirradiated parents and their 200 offspring, we selected seven highly mutable loci (0.5-1.0 x 10(-2) mutants per locus per gamete) and two bonus loci for further study. To determine if radiation exposure increases mutation frequencies in these loci, medaka were chronically irradiated from subadults through maturation at relatively low dose rates of 68 mGy/d. Total doses for males and females were 10.4 and 3 Gy, respectively. The mean number of mutations for the offspring of exposed families (0.149+/-0.044) was significantly higher (P=0.018) than for control families (0.080+/-0.028), indicating induction of germline mutations from chronic irradiation. This increase in the microsatellite mutation rate is greater than expected from direct interaction of radiation with DNA, suggesting indirect, untargeted mechanism(s) for mutations. This study identified microsatellite loci with a high mutational background in medaka, variation among loci and families as important variables, and demonstrated the usefulness of this fish model for studying radiation-induced germline mutations.
Collapse
Affiliation(s)
- O Tsyusko
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA.
| | | | | | | | | | | | | |
Collapse
|
8
|
Goda T, Abu-Daya A, Carruthers S, Clark MD, Stemple DL, Zimmerman LB. Genetic screens for mutations affecting development of Xenopus tropicalis. PLoS Genet 2006; 2:e91. [PMID: 16789825 PMCID: PMC1475704 DOI: 10.1371/journal.pgen.0020091] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Accepted: 04/28/2006] [Indexed: 11/18/2022] Open
Abstract
We present here the results of forward and reverse genetic screens for chemically-induced mutations in Xenopus tropicalis. In our forward genetic screen, we have uncovered 77 candidate phenotypes in diverse organogenesis and differentiation processes. Using a gynogenetic screen design, which minimizes time and husbandry space expenditures, we find that if a phenotype is detected in the gynogenetic F2 of a given F1 female twice, it is highly likely to be a heritable abnormality (29/29 cases). We have also demonstrated the feasibility of reverse genetic approaches for obtaining carriers of mutations in specific genes, and have directly determined an induced mutation rate by sequencing specific exons from a mutagenized population. The Xenopus system, with its well-understood embryology, fate map, and gain-of-function approaches, can now be coupled with efficient loss-of-function genetic strategies for vertebrate functional genomics and developmental genetics.
Collapse
Affiliation(s)
- Tadahiro Goda
- Division of Developmental Biology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, United Kingdom
| | - Anita Abu-Daya
- Division of Developmental Biology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, United Kingdom
| | - Samantha Carruthers
- Vertebrate Development and Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Matthew D Clark
- Vertebrate Development and Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Derek L Stemple
- Vertebrate Development and Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
- * To whom correspondence should be addressed. E-mail: (DLS); (LBZ)
| | - Lyle B Zimmerman
- Division of Developmental Biology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, United Kingdom
- * To whom correspondence should be addressed. E-mail: (DLS); (LBZ)
| |
Collapse
|
9
|
Bouffler SD, Bridges BA, Cooper DN, Dubrova Y, McMillan TJ, Thacker J, Wright EG, Waters R. Assessing radiation-associated mutational risk to the germline: repetitive DNA sequences as mutational targets and biomarkers. Radiat Res 2006; 165:249-68. [PMID: 16494513 DOI: 10.1667/rr3506.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This review assesses recent data on mutational risk to the germline after radiation exposure obtained by molecular analysis of tandemly repeated DNA loci (TRDLs): minisatellites in humans and expanded simple tandem repeats in mice. Some studies, particularly those including exposure to internal emitters, indicate that TRDL mutation can be used as a marker of human radiation exposure; most human studies, however, are negative. Although mouse studies have suggested that TRDL mutation analysis may be more widely applicable in biomonitoring, there are important differences between the structure of mouse and human TRDLs. Mutational mechanisms probably differ between the two species, and so care should be taken in predicting effects in humans from mouse data. In mice and humans, TRDL mutations are largely untargeted with only limited evidence of dose dependence. Transgenerational mutation has been observed in mice but not in humans, but the mechanisms driving such mutation transmission are unknown. Some minisatellite variants are associated with human diseases and may affect gene transcription, but causal relationships have not yet been established. It is concluded that at present the TRDL mutation data do not warrant a dramatic revision of germline or cancer risk estimates for radiation.
Collapse
Affiliation(s)
- S D Bouffler
- Health Protection Agency Radiation Protection Division, Chilton, Didcot, Oxon OX11 0RQ, United Kingdom.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Kimura T, Yoshida K, Shimada A, Jindo T, Sakaizumi M, Mitani H, Naruse K, Takeda H, Inoko H, Tamiya G, Shinya M. Genetic linkage map of medaka with polymerase chain reaction length polymorphisms. Gene 2005; 363:24-31. [PMID: 16226856 DOI: 10.1016/j.gene.2005.07.043] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Revised: 06/15/2005] [Accepted: 07/22/2005] [Indexed: 11/28/2022]
Abstract
With recent improvements in genetic and genomic infrastructures, great interest has been taken in genetic dissection of multi-factorial traits. A genetic map consisting of markers that are highly polymorphic and rapidly genotyped is essential for the genetic mapping of such a complex trait. Medaka, Oryzias latipes, is an excellent model system for genetic studies. To promote genetic mapping of complex traits in medaka we developed the first high-throughput and genome-wide marker set in the organism by using its genomic information and the bioinformatic techniques. We tested 545 primer pairs and obtained 265 co-dominant markers between two inbred strains, HNI and Hd-rR. Our map, consisting of 231 uniquely mapped markers, covers 1257.3 centimorgan (cM) of the medaka genome with an average interval distance of 5.4 cM. Furthermore, the newly designed markers were examined for polymorphisms among six medaka inbred strains: HNI, Hd-rR and four additional strains. Most of our markers are simple sequence length polymorphisms (SSLPs) and can be rapidly genotyped by an automated system under a single polymerase chain reaction (PCR) condition. Together with the genotyping data of six medaka inbred strains, our new marker set provides a powerful tool for genome-wide analysis of complex biological phenomena found widely in medaka populations.
Collapse
Affiliation(s)
- Tetsuaki Kimura
- Department of Molecular Life Science, Course of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Kanagawa 259-1193, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Shimada A, Shima A, Nojima K, Seino Y, Setlow RB. Germ cell mutagenesis in medaka fish after exposures to high-energy cosmic ray nuclei: A human model. Proc Natl Acad Sci U S A 2005; 102:6063-7. [PMID: 15829584 PMCID: PMC1087928 DOI: 10.1073/pnas.0500895102] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Astronauts beyond the Earth's orbit are exposed to high-energy cosmic-ray nuclei with high values of linear energy transfer (LET), resulting in much more biological damage than from x-rays or gamma-rays and may result in mutations and cancer induction. The relative biological effectiveness of these nuclei depends on the LET, rising to as high as approximately 50 at LET values of approximately 100-200 keV/microm. An endpoint of concern is germ cell mutations passed on to offspring, arising from exposure to these nuclei. A vertebrate model for germ cell mutation is Medaka fish (Oryzias latipes). We exposed wild type males to doses of 1 GeV per nucleon Fe nuclei or to 290 MeV per nucleon C nuclei. They were mated to females with recessive mutations at five-color loci. The transparent embryos from >100 days of mating (representing exposed sperm, spermatids, or spermatogonia) were observed so as to detect dominant lethal mutations and total color mutations, even though the embryos might not hatch. The relative number of mutant embryos as a function of dose were compared with those induced by gamma-rays. The relative biological effectiveness values for dominant lethal mutations and total color mutations for exposed sperm and spermatids were 1.3-2.1 for exposure to C nuclei and 1.5-3.0 for exposure to Fe nuclei. (The spermatogonial data were uncertain.) These low values, and the negligible number of viable mutations, compared with those for mutations in somatic cells and for neoplastic transformation, indicate that germ cell mutations arising from exposures to cosmic ray nuclei are not a significant hazard to astronauts.
Collapse
Affiliation(s)
- Atsuko Shimada
- Department of Biological Sciences, School of Sciences, University of Tokyo, Tokyo 113-0033, Japan
| | | | | | | | | |
Collapse
|
12
|
López A, Xamena N, Marcos R, Velázquez A. Germline genomic instability in PCNA mutants of Drosophila: DNA fingerprinting and microsatellite analysis. Mutat Res 2005; 570:253-65. [PMID: 15708584 DOI: 10.1016/j.mrfmmm.2004.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2004] [Revised: 11/04/2004] [Accepted: 11/26/2004] [Indexed: 11/29/2022]
Abstract
PCNA participates in multiple processes of DNA metabolism with an essential role in DNA replication and intervening in DNA repair. Temperature-sensitive PCNA mutants of Drosophila (mus209) are sensitive to mutagens, impair developmental processes and suppress positional-effect variegation. To investigate the role of proliferating cell nuclear antigen (PCNA) in germline genomic stability, independent mus209-defective and mus209-normal lines were established and maintained over six generations. A time course study was carried out and general genomic alterations were analyzed in the progeny by using arbitrarily primed PCR (AP-PCR) and microsatellite analysis. The AP-PCR analysis has shown that a dysfunctional PCNA leads to germline genomic instability, being the amount of genomic alterations transmitted to the progeny directly related to the number of mus209B1 mutant alleles. In addition, we have found that the frequency of genomic alterations tends to increase over successive generations. Surprisingly, the highest microsatellite instability was found in the heterozygous mus209-defective lines, suggesting a greater mutation rate in these individuals, in comparison with the homozygous mus209-defective lines. In conclusion, our results clearly indicate that PCNA is an important factor to maintain genomic stability in germinal cells, both in the overall genome and in simple repeated sequences. The implication of PCNA mutations in transgenerational genomic instability and related to cancer susceptibility is also discussed.
Collapse
Affiliation(s)
- Arturo López
- Grup de Mutagènesi, Unitat de Genètica, Edifici Cn, Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | | | | | | |
Collapse
|
13
|
Klüver N, Kondo M, Herpin A, Mitani H, Schartl M. Divergent expression patterns of Sox9 duplicates in teleosts indicate a lineage specific subfunctionalization. Dev Genes Evol 2005; 215:297-305. [PMID: 15818483 DOI: 10.1007/s00427-005-0477-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Accepted: 02/15/2005] [Indexed: 01/27/2023]
Abstract
Sry-related HMG-box genes are key regulators of several developmental processes. Sox9 encodes a transcription factor required for cartilage formation and testis determination in mammals. In zebrafish (Danio rerio) and stickleback (Gasterosteus aculeatus) two co-orthologs of Sox9 are present. To date, only one Sox9 had been identified in medaka (Oryzias latipes). We have now isolated the second Sox9 gene. Sequence analysis, phylogenetic data, linkage mapping as well as expression pattern all together suggest that the medaka Sox9a and Sox9b are co-orthologs. During embryogenesis, the expression pattern of Sox9a and Sox9b are distinct but overlap considerably in craniofacial cartilage elements. Comparing the zebrafish Sox9a and Sox9b expression patterns with medaka Sox9a and Sox9b expression domains revealed that some are identical but others are clearly different. We conclude that Sox9 regulatory subfunctions were not partitioned before divergence of the teleosts and evolved to lineage-specific expression domains.
Collapse
Affiliation(s)
- Nils Klüver
- Department of Physiological Chemistry I, University of Würzburg, 97074 Würzburg, Germany
| | | | | | | | | |
Collapse
|
14
|
Shimada A, Eguchi H, Yoshinaga S, Shima A. Dose-rate effect on transgenerational mutation frequencies in spermatogonial stem cells of the medaka fish. Radiat Res 2005; 163:112-4. [PMID: 15606314 DOI: 10.1667/rr3266] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The estimation of transgenerational genetic risk of radiation exposure to non-human species is crucial for the protection of ecosystems. Here we determined the frequency of specific-locus mutations at the five pigmentation loci in medaka spermatogonial stem cells after gamma irradiation at 0.03 cGy/min and 95 cGy/min. At each total dose, the mutation frequency was significantly lower in the 0.03-cGy/min group than in the 95-cGy/min group, suggesting a dose-rate effect. The ratio of the induced mutation frequency at 0.03 cGy/min to that at 95 cGy/min was approximately 0.42 from 0 to 1.9 Gy and approximately 0.33 from 1.9 to 4.75 cGy. In the mouse, this ratio is estimated to be 0.33 (Russell and Kelly, Proc. Natl. Acad. Sci. USA 79, 542-544, 1982). It is thus possible that the magnitude of the dose-rate effect on transgenerational mutation frequencies is comparable between mouse and medaka spermatogonia, suggesting similar dose-rate effects among vertebrates.
Collapse
Affiliation(s)
- Atsuko Shimada
- Department of Biological Sciences, School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
| | | | | | | |
Collapse
|
15
|
Shima A, Mitani H. Medaka as a research organism: past, present and future. Mech Dev 2005; 121:599-604. [PMID: 15210169 DOI: 10.1016/j.mod.2004.03.011] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2003] [Revised: 03/16/2004] [Accepted: 03/17/2004] [Indexed: 11/30/2022]
Abstract
This introductory review briefly describes the history of medaka as a research organism and the previous accomplishments of the medaka field. The medaka genome project currently underway through the efforts of an international consortium, the Medaka Genome Initiative, and the future prospects for medaka research, particularly for genomic analyses, are also discussed.
Collapse
Affiliation(s)
- Akihiro Shima
- Department of Integrated Biosciences 102, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa City, Chiba 277-8562, Japan.
| | | |
Collapse
|
16
|
Shimada A, Shima A. Transgenerational genomic instability as revealed by a somatic mutation assay using the medaka fish. Mutat Res 2004; 552:119-24. [PMID: 15288545 DOI: 10.1016/j.mrfmmm.2004.06.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2004] [Revised: 05/04/2004] [Accepted: 05/07/2004] [Indexed: 10/26/2022]
Abstract
We previously established a somatic mutation assay of the medaka wl (white leucophores) locus based on visual inspection, and showed that somatic mutations at paternally derived alleles frequently arise during the development of F1 embryos fertilized by sperm/late spermatids that had been exposed to gamma-rays. To further study such delayed mutations, we determined the frequency of mutant embryos obtained from three different crosses between irradiated males and non-irradiated females. When sperm and late spermatids were irradiated, the mutant frequency within non-irradiated maternally derived alleles was approximately 3 times higher than in the control group. In the F2 generation, however, no increase in mutant frequency was observed. Similarly, there was no significant increase in the F1 mutant frequency when stem spermatogonia were irradiated. These data suggest that irradiation of sperm and late spermatids can induce indirect mutations in F1 somatic cells, supporting the idea that genomic instability arises during F1 embryonic development. Moreover, such instability apparently arises most frequently when eggs are fertilized just after the sperm are irradiated.
Collapse
Affiliation(s)
- Atsuko Shimada
- Department of Biological Sciences, School of Sciences, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
| | | |
Collapse
|
17
|
Naruse K, Hori H, Shimizu N, Kohara Y, Takeda H. Medaka genomics: a bridge between mutant phenotype and gene function. Mech Dev 2004; 121:619-28. [PMID: 15210171 DOI: 10.1016/j.mod.2004.04.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2004] [Revised: 03/05/2004] [Accepted: 05/14/2004] [Indexed: 11/17/2022]
Abstract
Recent advances in medaka genetics have proven that the medakafish is an excellent model system for developmental and evolutionary biology studies and that it can complement similar studies in zebrafish. Large-scale mutagenesis projects are now being conducted by several groups in Japan and are delivering a vastly expanded pool of medaka mutant stocks. This growing availability of genomic resources will greatly accelerate progress in moving from mutant phenotypes to the elucidation of gene function. This phenotype-driven approach can be expected to lead to the identification and characterization of novel genes and pathways in vertebrate genomes. This review discusses the current state of medaka genomic resources, the state of medaka gene mapping and medaka genome sequencing projects.
Collapse
Affiliation(s)
- Kiyoshi Naruse
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | | | | | | | | |
Collapse
|
18
|
Takai A, Kagawa N, Fujikawa K. Susceptibility of male and female medaka (Oryzias latipes) fish to spontaneous and X-ray induced micronucleus formation in gill cells. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2004; 558:131-6. [PMID: 15036126 DOI: 10.1016/j.mrgentox.2003.11.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2003] [Revised: 11/21/2003] [Accepted: 11/21/2003] [Indexed: 11/19/2022]
Abstract
The frequency of micronucleated cells (MNCs) was measured in acridine-orange (AO) stained RNA-rich gill cells from male and female medaka (Oryzias latipes) fish of known body weight. Spontaneous MNC frequencies were not significantly correlated with body weight, despite the fact that the heaviest of the 30 fish used outweighed the lightest by a factor of 3. Average MNC frequencies were identical in males and females at 0.8 per thousand. An X-ray dose of 4 Gy increased the frequency of MNCs over the spontaneous level in all 30 of the fish used, reaching a level of 7.2 per thousand on average when assayed 24 h after exposure. In X-ray treated fish, MNC frequency and body weight were not significantly correlated, nor was there any difference between the sexes. These and other results support our primary conclusion that AO-staining is suitable for the medaka micronucleus assay in gill cells, and indicate that male and female medaka fish are similarly and size-independently susceptible to both spontaneous and X-ray induced micronucleus formation in gill cells.
Collapse
Affiliation(s)
- Akinori Takai
- Department of Human and Environmental Sciences, Osaka Shin-Ai College, 6-2-28 Tsurumi, Tsurumi-ku, Osaka 538-0053, Japan.
| | | | | |
Collapse
|
19
|
Hinton TG, Coughlin DP, Yi Y, Marsh LC. Low Dose Rate Irradiation Facility: initial study on chronic exposures to medaka. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2004; 74:43-55. [PMID: 15063535 DOI: 10.1016/j.jenvrad.2004.01.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Uncertainties associated with the effects from chronic low-level exposures to radiation prompted us to construct a Low Dose Rate Irradiation Facility (LoDIF). The facility was designed specifically to test the appropriateness of the 10 mGy d(-1) guideline often espoused as acceptable for protection of aquatic biota from ionizing radiation. Scientists at the 0.4 ha facility use 40 outdoor mesocosms and 137Cs irradiators of three different source strengths to research the effects of chronic low-level irradiation at different levels of biological organization. A description of the facility is included along with results from a pilot study in which Japanese medaka (a small fish native to Asia) were chronically irradiated at the highest dose rate possible within the facility (350+/-150 mGy d(-1)). Irradiated fish produced fewer eggs per day (p=0.03); had a lower percentage of viable eggs (p=0.04), and produced a lower percentage of hatchlings (p=0.05). Although these data are not surprising based on the relatively high dose rates, they are important to future work at the LoDIF because they confirm the utility of our chosen model organism for detecting population-level responses, and they illustrate the statistical power achieved from using replicated mesocosms, in that statistical significance was achieved with few replicates per treatment. Future directions for the LoDIF are presented, as well as an invitation for interested researchers to participate in our studies.
Collapse
Affiliation(s)
- T G Hinton
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA.
| | | | | | | |
Collapse
|
20
|
Takai A, Kagawa N, Fujikawa K. Dose- and time-dependent responses for micronucleus induction by X-rays and fast neutrons in gill cells of medaka (Oryzias latipes). ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2004; 44:108-112. [PMID: 15278914 DOI: 10.1002/em.20042] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Medaka fish (Oryzias latipes) were exposed to various doses of X-rays or fast neutrons, and the frequency of micronucleated cells (MNCs) was measured in gills sampled at 12- or 24-hr intervals from 12 to 96 hr after exposure. The resulting time course of MNC frequency was biphasic, with a clear peak 24 hr after exposure, irrespective of the kind of radiation applied and the dose used. The half-life of MNCs induced in the gill tissues by the two exposures fluctuated around 28 hr, with no significant dose-dependent trend for either X-ray- or neutron-exposed fish. As assayed 24 hr after exposure, the MNC frequency increased linearly over the control level with increasing doses of both X-rays and fast neutrons. The relative biological effectiveness (RBE) of fast neutrons to X-rays for MNC induction was estimated to be 4.3 +/- 0.6. This value is close to the RBE value of 5.1 +/- 0.3 reported for fast neutron induction of somatic crossing-over mutations in Drosophila melanogaster that arise from recombination repair of DNA double-strand breaks. These results and other data support our conclusion that the medaka gill cell micronucleus assay is a reliable short-term test for detecting potential inducers of DNA double-strand breaks.
Collapse
Affiliation(s)
- Akinori Takai
- Department of Human and Environmental Sciences, Osaka Shin-Ai College, Tsurumi, Tsurumi-ku, Japan.
| | | | | |
Collapse
|
21
|
Niwa O. Induced genomic instability in irradiated germ cells and in the offspring; reconciling discrepancies among the human and animal studies. Oncogene 2003; 22:7078-86. [PMID: 14557813 DOI: 10.1038/sj.onc.1207037] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many studies confirmed that radiation induces genomic instability in whole-body systems. However, the results of the studies are not always consistent with each other. Attempts are made in the present review to resolve the discrepancies. Many of the studies in human and experimental animals utilize the length change mutation of minisatellite sequences as a marker of genomic instability. Minisatellite sequences frequently change their length, and the data obtained by conventional Southern blotting give rather qualitative information, which is sometimes difficult to scrutinize quantitatively. This is the problem inevitably associated with the study of minisatellite mutations and the source of some conflicts among studies in humans and mice. Radiation induction of genomic instability has also been assessed in whole-body experimental systems, using other markers such as the mouse pink-eyed unstable allele and the specific pigmentation loci of medaka fish (Oryzias latipes). Even though there are some contradictions, all these studies have demonstrated that genomic instability is induced in the germ cells of irradiated parents, especially of males, and in offspring born to them. Among these, transmission of genomic instability to the second generation of irradiated parents is limited to the mouse minisatellite system, and awaits further clarification in other experimental systems.
Collapse
Affiliation(s)
- Ohtsura Niwa
- Radiation Biology Center, Kyoto University, Yoshida-Konoe, Sakyo-ku, Kyoto 606-8501, Japan.
| |
Collapse
|
22
|
Kuwahara Y, Shimada A, Mitani H, Shima A. Gamma-ray exposure accelerates spermatogenesis of medaka fish, Oryzias latipes. Mol Reprod Dev 2003; 65:204-11. [PMID: 12704732 DOI: 10.1002/mrd.10261] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To examine the spermatogenesis (and spermiogenesis) cell population kinetics after gamma-irradiation, the frequency and fate of BrdU-labeled pre-meiotic spermatogenic cells (spermatogonia and pre-leptotene spermatocytes) and spermatogonial stem cells (SSCs) of the medaka fish (Oryzias latipes) were examined immunohistochemically and by BrdU-labeling. After 4.75 Gy of gamma-irradiation, a statistically significant decrease in the frequency of BrdU-labeled cells was detected in the SSCs, but not in pre-meiotic spermatogenic cells. The time necessary for differentiation of surviving pre-meiotic spermatogenic cells without delay of germ cell development was shortened. More than 90% of surviving pre-meiotic spermatogenic cells differentiated into haploid cells within 5 days after irradiation, followed by a temporal spermatozoa exhaust in the testis. Next, spermatogenesis began in the surviving SSCs. However, the outcome was abnormal spermatozoa, indicating that accelerated maturation process led to morphological abnormalities. Moreover, 35% of the morphologically normal spermatozoa were dead at day 6. Based on these results, we suggest a reset system; after irradiation most surviving spermatogenic cells, except for the SSCs, are prematurely eliminated from the testis by spermatogenesis (and spermiogenesis) acceleration, and subsequent spermatogenesis begins with the surviving SSCs, a possible safeguard against male germ cell mutagenesis.
Collapse
Affiliation(s)
- Yoshikazu Kuwahara
- Laboratory of Radiation Biology, Department of Biological Sciences, Graduate School of Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Tokyo 277-8562, Japan.
| | | | | | | |
Collapse
|
23
|
Nakano E, Watanabe LC, Ohlweiler FP, Pereira CADB, Kawano T. Establishment of the dominant lethal test in the freshwater mollusk Biomphalaria glabrata (Say, 1818). Mutat Res 2003; 536:145-54. [PMID: 12694755 DOI: 10.1016/s1383-5718(03)00042-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mutagens in the environment may represent a long-term risk for ecosystems. The reproductive potential of populations can be affected by alterations in the fecundity and offspring viability caused by germ cell mutations. Despite the ecological relevance of these effects, there are few studies on germ cell mutagenicity in natural populations. Biomphalaria glabrata was chosen for this study because of the scarcity of data on freshwater invertebrates and the ecological importance of this group. The aim of this study was to establish a germ cell mutagenicity test in B. glabrata by using a similar approach to that used in the dominant lethal test in rodents. Mitomycin C was used as a direct mutagen and cyclophosphamide as a mutagen that requires metabolic activation. Wild-type snails were exposed for 10 days to three concentrations of each agent and crossed with non-exposed albino snails at the end of the treatment. The total frequencies of malformations were analyzed in the offspring of wild-type snails; among the offspring of albino snails, only the heterozygous wild-type embryos were analyzed for malformations. Both agents induced germ cell mutations. The analysis of the offspring of the wild-type snails showed an effect of the exposure up to approximately 5 days after the end of the treatment with cyclophosphamide; the effect of mitomycin C was observed until 45 days after the end of the exposure. There was an increase in the frequencies of malformations in the wild-type offspring of the non-exposed albino snails crossed with the wild-type snails exposed to both agents. The dominant lethal test in B. glabrata proposed in this work is easy to perform, efficient, specific and sensitive in the evaluation of germ cell mutations induced by reference mutagens. The possibility of expanding its use to environmental biomonitoring studies seems very promising and worth trying.
Collapse
Affiliation(s)
- Eliana Nakano
- Laboratório de Parasitologia/Malacologia, Instituto Butantan, Avenida Vital Brasil, 1500, CEP 05503-900, São Paulo, Brazil.
| | | | | | | | | |
Collapse
|
24
|
Lee JS, Chang SY, Kim IC, Han MS, Lee YS, Lee YS. Teratogenic effects of N-ethyl-N-nitrosourea (ENU) on larvae of the self-fertilizing fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae). TERATOGENESIS, CARCINOGENESIS, AND MUTAGENESIS 2002; 22:363-7. [PMID: 12210499 DOI: 10.1002/tcm.10031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We showed that N-Ethyl-N-Nitrosourea (ENU) induces teratogenesis in larvae of the self-fertilizing fish Rivulus marmoratus. We discuss this and the issue of carcinogenesis caused by ENU.
Collapse
Affiliation(s)
- Jae-Seong Lee
- Department of Environmental Science, Graduate School, Hanyang University, Seoul, South Korea.
| | | | | | | | | | | |
Collapse
|
25
|
Atienzar FA, Venier P, Jha AN, Depledge MH. Evaluation of the random amplified polymorphic DNA (RAPD) assay for the detection of DNA damage and mutations. Mutat Res 2002; 521:151-63. [PMID: 12438012 DOI: 10.1016/s1383-5718(02)00216-4] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The random amplified polymorphic DNA (RAPD) assay and related techniques like the arbitrarily primed polymerase chain reaction (AP-PCR) have been shown to detect genotoxin-induced DNA damage and mutations. The changes occurring in RAPD profiles following genotoxic treatments include variation in band intensity as well as gain or loss of bands. However, the interpretation of the molecular events responsible for differences in the RAPD patterns is not an easy task since different DNA alterations can induce similar type of changes. In this study, we evaluated the effects of a number of DNA alterations on the RAPD profiles. Genomic DNA from different species was digested with restriction enzymes, ultrasonicated, treated with benzo[a]pyrene (B[a]P) diol epoxide (BPDE) and the resulting RAPD profiles were evaluated. In comparison to the enzymatic DNA digestions, sonication caused greater changes in the RAPD patterns and induced a dose-related disappearance of the high molecular weight amplicons. A DNA sample substantially modified with BPDE caused very similar changes but amplicons of low molecular weight were also affected. Appearance of new bands and increase in band intensity were also evident in the RAPD profiles generated by the BPDE-modified DNA. Random mutations occurring in mismatch repair-deficient strains did not cause any changes in the banding patterns whereas a single base change in 10-mer primers produced substantial differences. Finally, further research is required to better understand the potential and limitations of the RAPD assay for the detection of DNA damage and mutations.
Collapse
Affiliation(s)
- Franck A Atienzar
- School of Biological Sciences, Plymouth Environmental Research Centre, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK.
| | | | | | | |
Collapse
|
26
|
López A, Baida A, Marcos R, Xamena N, Velázquez A. Spontaneous and bleomycin-induced genomic alterations in the progeny of Drosophila treated males depends on the Msh2 status. DNA fingerprinting analysis. DNA Repair (Amst) 2002; 1:941-54. [PMID: 12531022 DOI: 10.1016/s1568-7864(02)00146-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Deficiency in DNA mismatch repair (MMR) confers instability of simple repeated sequences and increases susceptibility to cancer. Some of the MMR genes are also implicated in other repair and cellular processes related to DNA damage response. Supposedly, lack of their function can lead to a global genomic instability, besides microsatellite instability (MSI). To study the spontaneous and induced genomic instability in germ cells, related to the Msh2 status, DNA alterations in the progeny of individual crosses of Drosophila deficient in one or two copies of the Msh2 gene, were analysed by the arbitrarily primed polymerase chain reaction (AP-PCR). The results indicate that the progeny of homozygous parents for the normal Msh2 allele (+/+) presents a significantly lower frequency of genomic alterations than those from heterozygous (+/-) or mutant homozygous (-/-) parents. In addition, the DNA damage transmitted to the progeny, after the adult parental males were exposed to bleomycin, indicates that whereas the induction of mutations related to MSI depends on the lack of the Msh2 function, the induction of other mutational events may require at least one functional Msh2 allele. Thus, the results obtained with heterozygous individuals may have special relevance for cancer development since they show that a disrupted Msh2 allele is enough to generate genomic instability in germ cells, increasing the genomic damage in the progeny of heterozygous individuals. This effect is enhanced by mutagenic stress, such as occurs after bleomycin exposure.
Collapse
Affiliation(s)
- A López
- Grup de Mutagènesi, Unitat de Genètica, Departament de Genètica i de Microbiologia, Edifici Cn, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | | | | | | | | |
Collapse
|
27
|
Kuwahara Y, Shimada A, Mitani H, Shima A. A critical stage in spermatogenesis for radiation-induced cell death in the medaka fish, Oryzias latipes. Radiat Res 2002; 157:386-92. [PMID: 11893240 DOI: 10.1667/0033-7587(2002)157[0386:acsisf]2.0.co;2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
To ensure the high-fidelity transmission by reproductive cells of genetic information from generation to generation, cells have evolved surveillance systems to eliminate genomic lesions by inducing cell suicide and/or DNA repair. In this report, gamma-ray-induced cell death was investigated using the medaka fish, Oryzias latipes, because of the ease with which the differentiation stages of its spermatogenic cells can be identified. After 4.75 Gy gamma irradiation, the maximum rate of death of spermatogonial stem cells was observed at 18 h, and that of differentiating spermatogonia was at 12 h, followed by a peak in the extent of DNA fragmentation detected by the TUNEL assay. Dose-response curves for the death rate showed an obvious increase in the death rate for early-differentiating spermatogonia even after 0.11 Gy irradiation, whereas there were no such increases for spermatogonial stem cells and late-differentiating spermatogonia. In the male germ cells of this fish, the stage during spermatogenesis most sensitive to radiation-induced cell death is in early-differentiating spermatogonia, the immediate descendants of the stem cells. These spermatogonia may have a rigorous surveillance system for genomic lesions induced in spermatogonial stem cells.
Collapse
Affiliation(s)
- Yoshikazu Kuwahara
- Laboratory of Radiation Biology, Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033, Japan.
| | | | | | | |
Collapse
|
28
|
Shimada A, Fukamachi S, Wakamatsu Y, Ozato K, Shima A. Induction and characterization of mutations at the b locus of the medaka, Oryzias latipes. Zoolog Sci 2002; 19:411-7. [PMID: 12130818 DOI: 10.2108/zsj.19.411] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The b locus is one of the most familiar pigmentation loci in the medaka, but its biochemical function is still unknown. Here we report induction of new mutations at the b locus by radiation and ENU. We also characterized all these mutations and previously isolated spontaneous ones on the phenotypic basis. Unexpectively, all the 18 induced mutations reduced melanin contents in both eyes and skin correlatively, although degree of reduction was varied from mutations to mutations. Moreover, presumed null mutants (bs8, bg8, bc2, bd3, bd6, bg13, bg19, bg24) had slightly melanized (dark red) eyes. These results suggest that the b-locus product plays an important but not a critical role in melanogenesis. The spontaneous mutants were divided into two types: one (bdl2, bdl3, and bp) had similarities with the induced mutants in that they had slightly colored eyes and skin, the other (bv, B', bd, bdl1, and b) exhibited normally black eyes but lightly colored skin. The present study supports our recent results (Fukamachi et al., 2001) that mutational changes were found in the coding region of the b gene in some of the mutants which reduced both eyes and skin melanogenesis, while the mutational change for the b allele could not be found there. We speculate that the bv, B', bd, bdl1, and b alleles might arise by the mutations in the regulatory region for skin melanogenesis.
Collapse
Affiliation(s)
- Atsuko Shimada
- Department of Biological Sciences, School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
| | | | | | | | | |
Collapse
|
29
|
Amanuma K, Tone S, Saito H, Shigeoka T, Aoki Y. Mutational spectra of benzo[a]pyrene and MeIQx in rpsL transgenic zebrafish embryos. Mutat Res 2002; 513:83-92. [PMID: 11719093 DOI: 10.1016/s1383-5718(01)00293-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To evaluate the rpsL transgenic zebrafish (Brachydanio rerio) mutation assay, we treated the embryos with benzo[a]pyrene (B[a]P) (10 microg/ml) or 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (300 microg/ml) for 16h and determined the mutation spectra. These treatments were previously reported to induce mutant frequencies that were 4.3 and 2.4 times the control value, respectively. In the B[a]P-treated group, half of the mutations were single base substitutions, 74% of which occurred at G:C base pairs. Among G:C base pair substitutions, G:C to T:A and G: C to C:G transversions were predominant, suggesting that B[a]P induced mutations in zebrafish embryos by mechanisms previously described in mammalian tissues. In the MeIQx-treated group, about 60% of the mutations were deletions. Some specific mutations were found, but the compound primarily amplified the background mutation level; improvement in the conditions of treatment may be required for elucidating MeIQx-mutagenesis in this system. This study showed that transgenic zebrafish may be a useful tool for detecting mutagens in aquatic environments and for elucidating mutagenic mechanisms.
Collapse
Affiliation(s)
- Kimiko Amanuma
- Division of Environmental Health Sciences, National Institute for Environmental Studies, Onogawa, Tsukuba 305-0053, Japan.
| | | | | | | | | |
Collapse
|
30
|
Abstract
Genome sequencing has yielded a plethora of new genes the function of which can be unravelled through comparative genomic approaches. Increasingly, developmental biologists are turning to fish as model genetic systems because they are amenable to studies of gene function. Zebrafish has already secured its place as a model vertebrate and now its Far Eastern cousin--medaka--is emerging as an important model fish, because of recent additions to the genetic toolkit available for this organism. Already, the popularity of medaka among developmental biologists has led to important insights into vertebrate development.
Collapse
Affiliation(s)
- Joachim Wittbrodt
- Developmental Biology Programme, EMBL-Heidelberg, Meyerhofstrasse 1, 69012 Heidelberg, Germany.
| | | | | |
Collapse
|
31
|
Atienzar FA, Evenden AJ, Jha AN, Depledge MH. Use of the random amplified polymorphic DNA (RAPD) assay for the detection of DNA damage and mutations: possible implications of confounding factors. Biomarkers 2002; 7:94-101. [PMID: 12101788 DOI: 10.1080/13547500110057425] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The aim of this study was to evaluate the potential of the random amplified polymorphic DNA (RAPD) assay to qualitatively detect the kinetics of benzo[a]pyrene (B[a]P)-induced DNA effects in the water flea Daphnia magna exposed to 25 and 50 micrograms l-1 B[a]P for 7 and 6 days, respectively. Mortality was recorded on a daily basis in both experiments, and RAPD analysis was performed on samples collected every day following isolation of genomic DNA. The main changes occurring in RAPD profiles produced by the population of Daphnia magna exposed to 25 and 50 micrograms l-1 B[a]P was a decrease and increase in band intensity, respectively. Most of the changes occurring in the RAPD patterns were likely to be the result of B[a]P-induced DNA damage (B[a]P DNA adducts, oxidized bases, DNA breakages) and/or mutations (point mutations and large rearrangements). In addition, reproducible changes also occurred in the profiles generated by control Daphnia magna. The results lead us to suggest that, in addition to B[a]P-induced DNA damage and mutations, factors such as variation in gene expression, steady levels of genetic alterations and changes in metabolic processes could induce some changes in RAPD patterns. Nevertheless, our data suggest that DNA damage and mutations appear to be the main factors influencing RAPD patterns. This study also emphasizes that unexpected variation in control profiles is not always associated with artefacts.
Collapse
Affiliation(s)
- Franck A Atienzar
- Department of Biological Sciences, Plymouth Environmental Research Centre (PERC), University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK.
| | | | | | | |
Collapse
|
32
|
Shimada A, Shima A. High incidence of mosaic mutations induced by irradiating paternal germ cells of the medaka fish, Oryzias latipes. Mutat Res 2001; 495:33-42. [PMID: 11448640 DOI: 10.1016/s1383-5718(01)00193-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Delayed-type mutations induced by radiation have recently been demonstrated in various somatic-cell systems. Such mutations are thought to result from the transmission of genetic instability through many cell divisions subsequent to a single exposure to ionizing radiation. Here, we have examined whether 'transgenerational' delayed-type mutations can arise during embryonic development of the medaka fish as a result of exposing the sperm and spermatids of live fish to 137Cs gamma-radiation. To do this, we made use of a sensitive specific-locus test (SLT) for the medaka that we have recently developed. Because the medaka has a transparent egg membrane and embryo body, both visible mosaics and whole-body mutations can be detected during development at an early-expressed pigmentation locus. When wild-type +/+ males were gamma-irradiated and then mated with wl/wl females, the frequency of F1 embryos with both wild-type orange leucophores (wl/+) and mutant-type white leucophores (wl/wl*) (mosaic mutants) was about 5.7x10(-3)/Gy. The frequency of embryos with only white leucophores (whole-body mutants) was about 1.3x10(-3)/Gy. These results suggest that delayed mutations frequently arise in medaka fish embryos that have been fertilized with irradiated sperm. Some possible mechanisms involved in the generation of these delayed mutational events (including genomic instability in the early embryos) are discussed.
Collapse
Affiliation(s)
- A Shimada
- Department of Biological Sciences, School of Sciences, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
| | | |
Collapse
|
33
|
Fukamachi S, Shimada A, Shima A. Mutations in the gene encoding B, a novel transporter protein, reduce melanin content in medaka. Nat Genet 2001; 28:381-5. [PMID: 11479596 DOI: 10.1038/ng584] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Pigmentation of the skin is of great social, clinical and cosmetic significance. Several genes that, when mutated, give rise to altered coat color in mice have been identified; their analysis has provided some insight into melanogenesis and human pigmentation diseases. Such analyses do not, however, fully inform on the pigmentation of lower vertebrates because mammals have only one kind of chromatophore, the melanocyte. In contrast, the medaka (a small, freshwater teleost) is a suitable model of the lower vertebrates because it has all kinds of chromatophores. The basic molecular genetics of fish are known and approximately 70 spontaneous pigmentation mutants have been isolated. One of these, an orange-red variant, is a homozygote of a well-known and common allele, b, and has been bred for hundreds of years by the Japanese. Here, we report the first successful positional cloning of a medaka gene (AIM1): one that encodes a transporter that mediates melanin synthesis. The protein is predicted to consist of 12 transmembrane domains and is 55% identical to a human EST of unknown function isolated from melanocytes and melanoma cells. We also isolated a highly homologous gene from the mouse, indicating a conserved function of vertebrate melanogenesis. Intriguingly, these proteins have sequence and structural similarities to plant sucrose transporters, suggesting a relevance of sucrose in melanin synthesis. Analysis of AIM1 orthologs should provide new insights into the regulation of melanogenesis in both teleosts and mammals.
Collapse
Affiliation(s)
- S Fukamachi
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa-no-ha 5-1-5, Kashiwa-shi, Chiba-ken 277-0882, Japan.
| | | | | |
Collapse
|
34
|
Fukamachi S, Shimada A, Naruse K, Shima A. Genomic analysis of gamma-ray-induced germ-cell mutations at the b locus recovered from the medaka specific-locus test. Mutat Res 2001; 458:19-29. [PMID: 11406418 DOI: 10.1016/s1383-5726(01)00009-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To study how gamma-ray-induced germ-cell mutations are fixed at the early embryonic stage of the next generation, genomic alterations in the b locus mutants (colorless melanophores) detected during development in the medaka specific-locus test (SLT) were analyzed. First, nine anonymous DNA markers linked to the b locus were cloned and mapped into the region extending about 47cM surrounding the b locus. Next, losses of paternal alleles of these DNA markers were examined in each of the 51 gamma-ray-induced b locus mutants obtained after irradiation of sperm or spermatids. In these mutants, 47 were dominant lethals, three were semi-viable and one was viable. All the mutants examined had large deletions surrounding the b locus. One viable mutant had an interstitial deletion, while all the semi-viable and dominant lethal ones appeared to have terminal deletions. Deletions extending about 20-35cM were the most frequently observed in 18 of the 51 mutants examined. The largest one extended more than 40cM. These results suggest that most of the gamma-ray induced germ cell mutations recovered as total specific-locus mutants were accompanied by large genomic deletions, which eventually led the mutant embryos to dominant lethality.
Collapse
Affiliation(s)
- S Fukamachi
- Laboratory of Radiation Biology, Department of Biological Sciences, School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, 113-0033, Tokyo, Japan.
| | | | | | | |
Collapse
|
35
|
Vasil'eva GV, Bezlepkin VG, Lomaeva MG, Sirota NP, Gaziev AI. AP-PCR assay of DNA alterations in the progeny of male mice exposed to low-level gamma-radiation. Mutat Res 2001; 485:133-41. [PMID: 11182544 DOI: 10.1016/s0921-8777(00)00066-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
By comparative analysis of fingerprints of arbitrarily primed polymerase chain reaction (AP-PCR) products, DNA alterations in somatic cells of the progeny (F1 generation) of male mice chronically exposed to low-doses of gamma-radiation was investigated. Male BALB/c mice exposed to 10-50 cGy were mated with unirradiated females 15 days after irradiation. DNA was isolated from biopsies taken from tail tips of 2-month-old progeny. Preliminary AP-PCRs were carried out with 17 primers representing core sequences of micro- and/or minisatellites or their flanking oligonucleotides. Best quantitatively reproduced AP-PCR fingerprints of genomic DNA were obtained with one of these primers, a 20-mer oligonucleotide flanking the micro-satellite locus Atplb2 on mouse chromosome 11. Comparative analysis of individual fingerprints of AP-PCR products obtained on DNA templates from the progeny of irradiated and intact males revealed an increased variability of micro-satellite-associated sequences and an increased frequency of "non-parental bands" in DNA-fingerprints from the progeny of males chronically exposed to gamma-radiation 15 days before mating (at the postmeiotic stage of spermatogenesis). The results show that increased micro-satellite instability can be initiated by irradiation of the male parent to subsequently arise or be transmitted to the soma of the F1 generations.
Collapse
Affiliation(s)
- G V Vasil'eva
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, Pushchino, 142290, Moscow, Russia
| | | | | | | | | |
Collapse
|
36
|
Atienzar FA, Cordi B, Donkin ME, Evenden AJ, Jha AN, Depledge MH. Comparison of ultraviolet-induced genotoxicity detected by random amplified polymorphic DNA with chlorophyll fluorescence and growth in a marine macroalgae, Palmaria palmata. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2000; 50:1-12. [PMID: 10930646 DOI: 10.1016/s0166-445x(99)00100-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The random amplified polymorphic DNA (RAPD) technique was used to detect DNA damage in the sublittoral macroalgae Palmaria palmata (Rhodophyta) exposed to both ambient and elevated irradiances of UV-B (280-315 nm). To investigate the potential of this method in ecotoxicological assessments, the qualitative and quantitative modifications in RAPD profiles were compared with changes in a number of physiological and fitness parameters. RAPD detectable modifications in DNA profiles were observed in all UV exposed individuals compared with controls. Changes in chlorophyll fluorescence (F(v)/F(m) ratio), in vivo pigment absorptance, thallus growth and RAPD profiles, examined simultaneously, provided a sensitive measure of UV-induced toxicity. In conclusion, the application of the RAPD method in conjunction with other suitable physiological and fitness measurements, may prove to be a valuable tool for investigating the specific effects of genotoxic agents upon marine algal populations. Ultimately, this methodology may allow the ecotoxicological examination of the link between molecular alterations and measurable adverse effects at higher levels of biological organisation.
Collapse
Affiliation(s)
- FA Atienzar
- Department of Biological Sciences, Plymouth Environmental Research Centre (PERC), University of Plymouth, Drake Circus, Plymouth, PL4 8AA, Devon, UK
| | | | | | | | | | | |
Collapse
|
37
|
Imai Y, Feldman B, Schier AF, Talbot WS. Analysis of chromosomal rearrangements induced by postmeiotic mutagenesis with ethylnitrosourea in zebrafish. Genetics 2000; 155:261-72. [PMID: 10790400 PMCID: PMC1461089 DOI: 10.1093/genetics/155.1.261] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations identified in zebrafish genetic screens allow the dissection of a wide array of problems in vertebrate biology. Most screens have examined mutations induced by treatment of spermatogonial (premeiotic) cells with the chemical mutagen N-ethyl-N-nitrosourea (ENU). Treatment of postmeiotic gametes with ENU induces specific-locus mutations at a higher rate than premeiotic regimens, suggesting that postmeiotic mutagenesis protocols could be useful in some screening strategies. Whereas there is extensive evidence that ENU induces point mutations in premeiotic cells, the range of mutations induced in postmeiotic zebrafish germ cells has been less thoroughly characterized. Here we report the identification and analysis of five mutations induced by postmeiotic ENU treatment. One mutation, snh(st1), is a translocation involving linkage group (LG) 11 and LG 14. The other four mutations, oep(st2), kny(st3), Df(LG 13)(st4), and cyc(st5), are deletions, ranging in size from less than 3 cM to greater than 20 cM. These results show that germ cell stage is an important determinant of the type of mutations induced. The induction of chromosomal rearrangements may account for the elevated frequency of specific-locus mutations observed after treatment of postmeiotic gametes with ENU.
Collapse
Affiliation(s)
- Y Imai
- Department of Developmental Biology, Beckman Center, Stanford University School of Medicine, Stanford, California 94305-5329, USA
| | | | | | | |
Collapse
|
38
|
Naruse K, Fukamachi S, Mitani H, Kondo M, Matsuoka T, Kondo S, Hanamura N, Morita Y, Hasegawa K, Nishigaki R, Shimada A, Wada H, Kusakabe T, Suzuki N, Kinoshita M, Kanamori A, Terado T, Kimura H, Nonaka M, Shima A. A detailed linkage map of medaka, Oryzias latipes: comparative genomics and genome evolution. Genetics 2000; 154:1773-84. [PMID: 10747068 PMCID: PMC1461045 DOI: 10.1093/genetics/154.4.1773] [Citation(s) in RCA: 221] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We mapped 633 markers (488 AFLPs, 28 RAPDs, 34 IRSs, 75 ESTs, 4 STSs, and 4 phenotypic markers) for the Medaka Oryzias latipes, a teleost fish of the order Beloniformes. Linkage was determined using a reference typing DNA panel from 39 cell lines derived from backcross progeny. This panel provided unlimited DNA for the accumulation of mapping data. The total map length of Medaka was 1354.5 cM and 24 linkage groups were detected, corresponding to the haploid chromosome number of the organism. Thirteen to 49 markers for each linkage group were obtained. Conserved synteny between Medaka and zebrafish was observed for 2 independent linkage groups. Unlike zebrafish, however, the Medaka linkage map showed obvious restriction of recombination on the linkage group containing the male-determining region (Y) locus compared to the autosomal chromosomes.
Collapse
Affiliation(s)
- K Naruse
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Atienzar FA, Conradi M, Evenden AJ, Jha AN, Depledge MH. Qualitative assessment of genotoxicity using random amplified polymorphic DNA: Comparison of genomic template stability with key fitness parameters in Daphnia magna exposed to benzo[a]pyrene. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 1999; 18:2275-2282. [PMID: 29857629 DOI: 10.1002/etc.5620181023] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/1998] [Accepted: 02/01/1999] [Indexed: 06/08/2023]
Abstract
A method of DNA profiling using the random amplified polymorphic DNA (RAPD) was used to assess toxicant-induced DNA effects in laboratory populations of Daphnia magna exposed to varying concentrations of the genotoxic hydrocarbon benzo[a]pyrene. These effects, represented by changes in the RAPD profiles, were compared with a number of key ecological fitness parameters (age-specific survival, age-specific fecundity, net reproductive rate, and intrinsic rate of population increase). Not only was the RAPD profiling method shown to be a rapid and reproducible assay of toxicant-induced DNA effects, but the qualitative measure of genomic template stability compared favorably with the traditional indices of fitness. The RAPD profiles, however, exhibited higher sensitivity in detecting toxic effects. The significance of these findings for future ecotoxicological studies is discussed.
Collapse
Affiliation(s)
- Franck A Atienzar
- Plymouth Environmental Research Center (PERC) and Department of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom
| | - Mercedes Conradi
- Plymouth Environmental Research Center (PERC) and Department of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom
| | - Andrew J Evenden
- Plymouth Environmental Research Center (PERC) and Department of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom
| | - Awadhesh N Jha
- Plymouth Environmental Research Center (PERC) and Department of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom
| | - Michael H Depledge
- Plymouth Environmental Research Center (PERC) and Department of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom
| |
Collapse
|