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Liu Z, Zhang Y, Jia X, Hoskins TD, Lu L, Han Y, Zhang X, Lin H, Shen L, Feng Y, Zheng Y, Hu C, Zhang H. Microcystin-LR Induces Estrogenic Effects at Environmentally Relevant Concentration in Black-Spotted Pond Frogs ( Pelophylax nigromaculatus): In Situ, In Vivo, In Vitro, and In Silico Investigations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:9559-9569. [PMID: 38710655 DOI: 10.1021/acs.est.4c01322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Harmful cyanobacterial blooms are frequent and intense worldwide, creating hazards for aquatic biodiversity. The potential estrogen-like effect of Microcystin-LR (MC-LR) is a growing concern. In this study, we assessed the estrogenic potency of MC-LR in black-spotted frogs through combined field and laboratory approaches. In 13 bloom areas of Zhejiang province, China, the MC-LR concentrations in water ranged from 0.87 to 8.77 μg/L and were correlated with sex hormone profiles in frogs, suggesting possible estrogenic activity of MC-LR. Tadpoles exposed to 1 μg/L, an environmentally relevant concentration, displayed a female-biased sex ratio relative to controls. Transcriptomic results revealed that MC-LR induces numerous and complex effects on gene expression across multiple endocrine axes. In addition, exposure of male adults significantly increased the estradiol (E2)/testosterone (T) ratio by 3.5-fold relative to controls. Downregulation of genes related to male reproductive endocrine function was also identified. We also showed how MC-LR enhances the expression of specific estrogen receptor (ER) proteins, which induce estrogenic effects by activating the ER pathway and hypothalamic-pituitary-gonadal (HPG) axis. In aggregate, our results reveal multiple lines of evidence demonstrating that, for amphibians, MC-LR is an estrogenic endocrine disruptor at environmentally relevant concentrations. The data presented here support the need for a shift in the MC-LR risk assessment. While hepatoxicity has historically been the focus of MC-LR risk assessments, our data clearly demonstrate that estrogenicity is a major mode of toxicity at environmental levels and that estrogenic effects should be considered for risk assessments on MC-LR going forward.
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Affiliation(s)
- Zhiquan Liu
- School of Engineering, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yinan Zhang
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Xiuying Jia
- Hangzhou City University, Hangzhou, Zhejiang 310015, China
| | - Tyler D Hoskins
- Department of Forestry & Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Liping Lu
- School of Public Health, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yu Han
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Xiaofang Zhang
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Huikang Lin
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Lilai Shen
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yixuan Feng
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yueyue Zheng
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Chao Hu
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Hangjun Zhang
- School of Engineering, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
- Hangzhou International Urbanology Research Center, Hangzhou 311121, China
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
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Phenotypic Plasticity in Juvenile Frogs That Experienced Predation Pressure as Tadpoles Does Not Alter Their Locomotory Performance. BIOLOGY 2023; 12:biology12030341. [PMID: 36979033 PMCID: PMC10045024 DOI: 10.3390/biology12030341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/11/2023] [Accepted: 02/20/2023] [Indexed: 02/24/2023]
Abstract
Anuran species can respond to environmental changes via phenotypic plasticity, which can also result in ecological impacts across the life history of such species. We investigated the effects of predation pressure (i.e., the non-consumption effect) from the dragonfly larva (Anax parthenope) on the phenotypical change of tadpoles into juvenile frogs (specifically the black-spotted pond frog, Pelophylax nigromaculatus), and also analyzed the impact of morphological changes on locomotory performance after metamorphosis. The experiments on predator impact were conducted in the laboratory. Body length, weight, development timing, and metamorphosis timing in the presence of dragonfly nymphs were measured in both tadpoles and juvenile frogs. The body and tail shapes of the tadpoles, as well as the skeletal shape of the juvenile frogs, were analyzed using landmark-based geometric morphometrics. Furthermore, the locomotory performance of the juvenile frogs was tested by measuring their jumping and swimming speeds. Tadpoles that had grown with predators possessed smaller bodies, deeper tail fins, and slower development rates, and they waited longer periods of time before commencing metamorphosis. Having said this, however, the effect of predator cues on the body length and weight of juvenile frogs was not found to be significant. These juvenile frogs possessed longer limbs and narrower skulls, with subtle morphological changes in the pelvis and ilium, but there was no subsequent difference in their swimming and jumping speeds. Our results showed that the changes in anatomical traits that can affect locomotor performance are so subtle that they do not affect the jumping or swimming speeds. Therefore, we support the view that these morphological changes are thus by-products of an altered tadpole period, rather than an adaptive response to predator-escape ability or to post-metamorphosis life history. On the other hand, delayed metamorphosis, without an increase in body size, may still be disadvantageous to the reproduction, growth, and survival of frogs in their life history following metamorphosis.
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Huang M, Liu Y, Dong W, Zhao Q, Duan R, Cao X, Wan Y, Yin J, Yi M. Toxicity of Pb continuous and pulse exposure on intestinal anatomy, bacterial diversity, and metabolites of Pelophylax nigromaculatus in pre-hibernation. CHEMOSPHERE 2022; 290:133304. [PMID: 34919911 DOI: 10.1016/j.chemosphere.2021.133304] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/10/2021] [Accepted: 12/12/2021] [Indexed: 06/14/2023]
Abstract
Amphibians are often exposed to pulse pollution due to fluctuational inputs of pollutants in water. Traditional ecotoxicology research is mainly performed under constant exposure conditions, which is not consistent with the true environmental pollution. Frogs are sensitive to changes in water pollutants in pre-hibernation. Thus, to understand the toxicity difference to continuous and pulse exposure in environmental concentrations of Pb (100 μg/L), Pelophylax nigromaculatus adults were exposed to short-term treatments (8 days) in pre-hibernation. Individual mortality, intestinal anatomical structure, bacterial diversity, and metabolites were measured in a control group (CON), a Pb continuous treatment group (CEPb) and a Pb pulse treatment group (PEPb). The results showed that PEPb significantly increased individual mortality, compared to the control group and CEPb. PEPb induced pathological changes in the small intestinal tissues, such as mucosal erosion, swollen and distorted villi, large vacuoles, and the proliferation of goblet cells. In addition, PEPb altered the structure and diversity of intestinal bacteria, resulting in an increase in some pathogenic bacteria (e.g. Bacteroides and Ruminococcus) and a decrease in beneficial bacteria (e.g. Cetobacterium and Akkermansia). Both CEPb and PEPb significantly changed intestinal metabolites and metabolic pathways. Moreover, PEPb has a significant effect on the metabolism of amino acids by increasing the content of 5-Aminopentanoic acid, cis-4-Hydroxy-l-proline, Glycocholic acid, l-Alanine, and l-Isoleucine. We concluded that PEPb may lead to intestine impairment of P. nigromaculatus in pre-hibernation by inducing intestinal structural integrity destruction, bacterial imbalance, and metabolic dysfunction, resulting in a significant increase in mortality. The study provides new insights for understanding the intestinal responses of frogs to pulse metal exposure.
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Affiliation(s)
- Minyi Huang
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Yang Liu
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Wenjing Dong
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Qiang Zhao
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Renyan Duan
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China.
| | - Xiaohong Cao
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Yuyue Wan
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Jiawei Yin
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Minghui Yi
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
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Zhao Q, Huang M, Liu Y, Wan Y, Duan R, Wu L. Effects of atrazine short-term exposure on jumping ability and intestinal microbiota diversity in male Pelophylax nigromaculatus adults. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:36122-36132. [PMID: 33683588 DOI: 10.1007/s11356-021-13234-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
Atrazine, a common chemical pesticide, has toxicity to adult and juvenile amphibians in natural ecosystems; however, it is more common to study its effects on larvae instead of adults. This study assessed the impacts of atrazine in water through short-term exposure (7 days) on male black spotted frog (Pelophylax nigromaculatus) adults fed every day. The jumping ability, including jumping height, distance, time, and speed, was measured by 3D motion analysis software, and the intestinal content microbiota was determined by 16S rRNA amplicon sequencing with QIIME software. The results showed that male P. nigromaculatus exposure to 200 and 500 μg/L atrazine significantly increased jumping distance and jumping time compared to control groups. Conversely, 500 μg/L atrazine treatments significantly decreased the diversity and changed the composition and structure of intestinal content microflora in male P. nigromaculatus compared to control groups. At the phylum level, Chlamydiae was only detected in the control group, and Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Proteobacteria were the dominant microflora in the atrazine treatment groups. At the genus level, the abundance of Lactobacillus and Weissella significantly increased in atrazine treatment groups compared to control groups. This study can provide a new framework based on movement behavior and intestinal microbiota to evaluate the response of amphibians to short-term exposure to environmental pollution.
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Affiliation(s)
- Qiang Zhao
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Minyi Huang
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China.
| | - Yang Liu
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Yuyue Wan
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Renyan Duan
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China.
| | - Lianfu Wu
- Key Laboratory of Biodiversity Research and Ecological Conservation in Southwest Anhui Province, Anqing, 246011, Anhui, China
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The rise and fall of globins in the amphibia. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 37:100759. [PMID: 33202310 DOI: 10.1016/j.cbd.2020.100759] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 10/23/2020] [Accepted: 10/29/2020] [Indexed: 12/28/2022]
Abstract
The globin gene repertoire of gnathostome vertebrates is dictated by differential retention and loss of nine paralogous genes: androglobin, neuroglobin, globin X, cytoglobin, globin Y, myoglobin, globin E, and the α- and β-globins. We report the globin gene repertoire of three orders of modern amphibians: Anura, Caudata, and Gymnophiona. Combining phylogenetic and conserved synteny analysis, we show that myoglobin and globin E were lost only in the Batrachia clade, but retained in Gymnophiona. The major amphibian groups also retained different paralogous copies of globin X. None of the amphibian presented αD-globin gene. Nevertheless, two clades of β-globins are present in all amphibians, indicating that the amphibian ancestor possessed two paralogous proto β-globins. We also show that orthologs of the gene coding for the monomeric hemoglobin found in the heart of Rana catesbeiana are present in Neobatrachia and Pelobatoidea species we analyzed. We suggest that these genes might perform myoglobin- and globin E-related functions. We conclude that the repertoire of globin genes in amphibians is dictated by both retention and loss of the paralogous genes cited above and the rise of a new globin gene through co-option of an α-globin, possibly facilitated by a prior event of transposition.
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Genomic Data Reveal Conserved Female Heterogamety in Giant Salamanders with Gigantic Nuclear Genomes. G3-GENES GENOMES GENETICS 2019; 9:3467-3476. [PMID: 31439718 PMCID: PMC6778777 DOI: 10.1534/g3.119.400556] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Systems of genetic sex determination and the homology of sex chromosomes in different taxa vary greatly across vertebrates. Much progress remains to be made in understanding systems of genetic sex determination in non-model organisms, especially those with homomorphic sex chromosomes and/or large genomes. We used reduced representation genome sequencing to investigate genetic sex determination systems in the salamander family Cryptobranchidae (genera Cryptobranchus and Andrias), which typifies both of these inherent difficulties. We tested hypotheses of male- or female-heterogamety by sequencing hundreds of thousands of anonymous genomic regions in a panel of known-sex cryptobranchids and characterized patterns of presence/absence, inferred zygosity, and depth of coverage to identify sex-linked regions of these 56 gigabase genomes. Our results strongly support the hypothesis that all cryptobranchid species possess homologous systems of female heterogamety, despite maintenance of homomorphic sex chromosomes over nearly 60 million years. Additionally, we report a robust, non-invasive genetic assay for sex diagnosis in Cryptobranchus and Andrias which may have great utility for conservation efforts with these endangered salamanders. Co-amplification of these W-linked markers in both cryptobranchid genera provides evidence for long-term sex chromosome stasis in one of the most divergent salamander lineages. These findings inform hypotheses about the ancestral mode of sex determination in salamanders, but suggest that comparative data from other salamander families are needed. Our results further demonstrate that massive genomes are not necessarily a barrier to effective genome-wide sequencing and that the resulting data can be highly informative about sex determination systems in taxa with homomorphic sex chromosomes.
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Li YY, Meng T, Gao K, Qin ZF. Gonadal differentiation and its sensitivity to androgens during development of Pelophylax nigromaculatus. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 202:188-195. [PMID: 30056249 DOI: 10.1016/j.aquatox.2018.07.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 07/19/2018] [Accepted: 07/19/2018] [Indexed: 06/08/2023]
Abstract
Our previous observations proposed Pelophylax nigromaculatus as a model species for studying the masculinizing effects of androgenic EDCs in amphibians. To better develop this model species, we studied the process of the gonadal differentiation/development and the sensitive stage to androgens. We found that the earliest sexual dimorphism in gonads at morphological and histological levels occurred at stages 38-40 and stage 36 respectively. Further examination of molecular markers for testicular and ovarian differentiation during development revealed that the cyp17 and cyp19 expressions were sexually dimorphic from stage 32 and stage 36 respectively. Further, we investigated the sex-reversal induced by 100 ng/L 5α-dihydrotestosterone (DHT) when exposures were initiated at stages 24, 26 and 28. We found that when exposed from stage 24, DHT resulted masculinization of all tadpoles with no typical ovaries, whereas exposures from stage 26 or 28 dramatically reduced the effect of DHT. Our findings show that gonads of P. nigromaculatus are bipotential at stage 24, in the process of differentiation at stage 26 and determined to become either testis or ovary at stage 28. Altogether, exposure of P. nigromaculatus should begin at stage 24 in order to sensitively detect masculinizing effects of EDCs. Present study provides useful information about the gonadal differentiation and development in P. nigromaculatus for effectively evaluating masculinizing effects of EDCs on gonads.
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Affiliation(s)
- Yuan-Yuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tan Meng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Kun Gao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Zhan-Fen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Chen J, Meng T, Li Y, Gao K, Qin Z. Effects of triclosan on gonadal differentiation and development in the frog Pelophylax nigromaculatus. J Environ Sci (China) 2018; 64:157-165. [PMID: 29478635 DOI: 10.1016/j.jes.2017.05.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/04/2017] [Accepted: 05/27/2017] [Indexed: 06/08/2023]
Abstract
Previous studies have reported that triclosan (TCS) could possess an androgenic activity. We aimed to investigate the effects of TCS on gonadal differentiation and development in the frog Pelophylax nigromaculatus, a sensitive amphibian species to androgenic chemicals. P. nigromaculatus tadpoles at stage 24 were exposed to TCS (3, 30, and 300nmol/L) to stage 46 in a semi-static exposure system. At the end of exposure, gonadal morphology and histology, sex ratio and gonadal expression of sex-biased genes were examined in P. nigromaculatus. In each TCS treatment group, we found several individuals whose gonads exhibited morphological and/or histological abnormalities. Gonadal histological abnormalities were characterized by few oocytes and many somatic cells. Although the percentage of the individuals with abnormal gonads was low (7.8%) among all animals treated with TCS, statistical test revealed the sex ratios in the 3 and 300nmol/L TCS treatment groups were significantly different from the solvent control. In the 30nmol/L TCS treatment group, abnormal gonads were also observed, although the sex ratio was not changed compared with the solvent control, which was possibly due to the smaller sample size in this group. In all the TCS treatment groups, the sex ratios were not obviously male-biased, but the expression levels of some sex-biased genes were significantly altered by TCS. Altogether, our results suggest that TCS, even at environmentally relevant concentrations, could disrupt gonadal differentiation and development in P. nigromaculatus, but we are not sure whether the disrupting effects were associated with masculinization or feminization.
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Affiliation(s)
- Juan Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Tan Meng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yuanyuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kun Gao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Zhanfen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Liu PY, Meng T, Li YY, Cai M, Li XH, Chen J, Qin ZF. Tetrabromoethylcyclohexane affects gonadal differentiation and development in the frog Pelophylax nigromaculatus. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 192:40-47. [PMID: 28917944 DOI: 10.1016/j.aquatox.2017.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 06/07/2023]
Abstract
Tetrabromoethylcyclohexane (TBECH), an additive brominated flame retardant, has been shown to have an androgenic activity in vitro. In the present study, we aimed to investigate the effects of TBECH on gonadal differentiation and development in the frog Pelophylax nigromaculatus, an amphibian species sensitive to androgenic chemicals, and to assess the androgenic activity of TBECH in vivo. P. nigromaculatus tadpoles were exposed to TBECH (1, 10, 100nM) from Gosner stage 24 to complete metamorphosis, and to 5α-dihydrotestosterone (DHT) as a positive control. We found that 1nM DHT resulted in 100% males, while the sex ratio in the solvent control group was close to 1:1. In all the TBECH treatment groups, sexually ambiguous gonads based on gross morphology and intersexualities with testicular and ovarian histological structures were found, but no abnormality occurred in the solvent control. In the 1, 10, 100nM TBECH treatment groups, the female percentages were 52%, 31%, 17%, with 36%, 56%, 66% for males and 12%, 13%, 17% for abnormal sexes, respectively. X2-test revealed significant differences in sex ratios between the three TBECH groups and the solvent control group, and the sex ratios in the two higher concentration groups were male-biased. These observations show that TBECH has a masculinizing effect on gonadal differentiation and development in P. nigromaculatus, suggesting an androgenic activity of TBECH in vivo. To our knowledge, this is the first study demonstrating that TBECH could induce gonadal masculinization in an animal, which raises new concerns for reproductive risk of TBECH exposure.
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Affiliation(s)
- Peng-Yan Liu
- College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei, China
| | - Tan Meng
- College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yuan-Yuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Man Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xing-Hong Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Juan Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhan-Fen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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Shi H, Gao T, Liu Z, Sun L, Jiang X, Chen L, Wang D. Blockage of androgen and administration of estrogen induce transdifferentiation of testis into ovary. J Endocrinol 2017; 233:65-80. [PMID: 28148717 DOI: 10.1530/joe-16-0551] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 02/01/2017] [Indexed: 12/24/2022]
Abstract
Induction of sex reversal of XY fish has been restricted to the sex undifferentiated period. In the present study, differentiated XY tilapia were treated with trilostane (TR), metopirone (MN) and glycyrrhetinic acid (GA) (inhibitor of 3β-HSD, Cyp11b2 and 11β-HSD, respectively) alone or in combination with 17β-estradiol (E2) from 30 to 90 dah (days after hatching). At 180 dah, E2 alone resulted in 8.3%, and TR, MN and GA alone resulted in no secondary sex reversal (SSR), whereas TR + E2, MN + E2 and GA + E2 resulted in 88.3, 60.0 and 46.7% of SSR, respectively. This sex reversal could be rescued by simultaneous administration of 11-ketotestosterone (11-KT). Compared with the control XY fish, decreased serum 11-KT and increased E2 level were detected in SSR fish. Immunohistochemistry analyses revealed that Cyp19a1a, Cyp11b2 and Dmrt1 were expressed in the gonads of GA + E2, MN + E2 and TR + E2 SSR XY fish at 90 dah, but only Cyp19a1a was expressed at 180 dah. When the treatment was applied from 60 to 120 dah, TR + E2 resulted in 3.3% of SSR, MN + E2 and GA + E2 resulted in no SSR. These results demonstrated that once 11-KT was synthesized, it could antagonize E2-induced male-to-female SSR, which could be abolished by simultaneous treatment with the inhibitor of steroidogenic enzymes. The upper the enzyme was located in the steroidogenic pathway, the higher SSR rate was achieved when it was inhibited as some of the precursors, such as androstenedione, testosterone and 5α-dihydrotestosterone, could act as androgens. These results highlight the key role of androgen in male sex maintenance.
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Affiliation(s)
- Hongjuan Shi
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education)Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, People's Republic of China
| | - Tian Gao
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education)Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, People's Republic of China
| | - Zhilong Liu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education)Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, People's Republic of China
| | - Lina Sun
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education)Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, People's Republic of China
| | - Xiaolong Jiang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education)Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, People's Republic of China
| | - Lili Chen
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education)Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, People's Republic of China
| | - Deshou Wang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education)Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, People's Republic of China
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Abstract
Amphibians have been widely used to study developmental biology due to the fact that embryo development takes place independently of the maternal organism and that observations and experimental approaches are easy. Some amphibians like Xenopus became model organisms in this field. In the first part of this article, the differentiation of the gonads in amphibians and the mechanisms governing this process are reviewed. In the second part, the state of the art about sex reversal, which can be induced by steroid hormones in general and by temperature in some species, is presented. Also information about pollutants found in the environment that could interfere with the development of the amphibian reproductive apparatus or with their reproductive physiology is given. Such compounds could play a part in the amphibian decline, since in the wild, many amphibians are endangered species.
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Affiliation(s)
- Stéphane Flament
- Université de Lorraine, CRAN, UMR 7039, and CNRS, CRAN, UMR 7039, Vandœuvre-lès-Nancy, France
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