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Brunelli E. Histological and ultrastructural alterations of the Italian newt (Lissotriton italicus) skin after exposure to ecologically relevant concentrations of nonylphenol ethoxylates. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2018; 60:17-27. [PMID: 29653385 DOI: 10.1016/j.etap.2018.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
Nonylphenol ethoxylates (NPEs) are well known endocrine disruptors. Widespread environmental contamination from NPEs is an issue of great concern. Despite amphibians are often exposed to such contaminants, very little attention has been dedicated to this vertebrate group. No information is available on the effects of NPEs onto the amphibian skin and only few reports have been conducted on fish. Here, histological and ultrastructural modifications of the skin have been evaluated in the Italian newt Lissotriton italicus. After a short-term exposure to two ecologically relevant concentrations of NP, severe pathological alterations, both dose and time-dependent, have been observed. The main effects were an increased mucous secretion, the dilation of the endomembrane, the wrinkling of the epidermal surface, the appearance of tubercles, the increased cellular turnover, continuous shedding processes. Some of the described skin alterations can easily interfere with physiological functions, such as osmoregulation and body protection, with detrimental consequences for the amphibian populations.
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Affiliation(s)
- Elvira Brunelli
- Department of Biology, Ecology and Earth Science (DiBEST), University of Calabria, Via P. Bucci 4/B, Rende, Cosenza, 87036, Italy.
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Morphological and immunohistochemical reactions of the larval epidermis in the Italian newt (Lissotriton italicus) after exposure to low pH. ZOOLOGY 2018; 126:20-28. [PMID: 29398350 DOI: 10.1016/j.zool.2018.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/08/2018] [Accepted: 01/08/2018] [Indexed: 01/18/2023]
Abstract
Mounting evidence suggests that amphibians are globally and currently the most threatened group of vertebrates and different causes might be responsible for this phenomenon. Acidification of water bodies is a global environmental issue that has been proposed as a possible cause for amphibian populations decline. Indeed, it has been widely demonstrated that low pH may exert harmful effects on amphibians, either directly or by increasing the adverse effects of other stressors. Surprisingly only few studies documented the response of amphibian integument to acidic pH conditions and no data are available on the effects of a non-lethal level of pH onto the amphibian larval epidermis. The present study showed that acidic pH (4.5) condition has severe effects on the epidermis of the Italian newt (Lissotriton italicus, formerly Triturus italicus) inducing both morphological and functional alterations. The increase of mucus is the first evident effect of acid injury, followed by the flattening of the epithelium and the appearance of a keratinized shedding layer. The immunolabeling of cytokeratins substantially changes acquiring an adult-like pattern. Also aquaporin 3 and iNOS expression modify their distribution according to a change of the histological features of the epidermis. These results clearly indicate that a short-term exposure to a sub-lethal pH disrupts the epidermis morphology and function in L. italicus larvae. Since the skin exerts a prominent role in both respiration and osmoregulation, the described alterations may adversely affect the overall ionic balance, with a long chain of cascading effects significantly decreasing newts survival probabilities when environmental pH lowering occurs.
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Alves RN, Gomes AS, Stueber K, Tine M, Thorne MAS, Smáradóttir H, Reinhard R, Clark MS, Rønnestad I, Power DM. The transcriptome of metamorphosing flatfish. BMC Genomics 2016; 17:413. [PMID: 27233904 PMCID: PMC4884423 DOI: 10.1186/s12864-016-2699-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 05/06/2016] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Flatfish metamorphosis denotes the extraordinary transformation of a symmetric pelagic larva into an asymmetric benthic juvenile. Metamorphosis in vertebrates is driven by thyroid hormones (THs), but how they orchestrate the cellular, morphological and functional modifications associated with maturation to juvenile/adult states in flatfish is an enigma. Since THs act via thyroid receptors that are ligand activated transcription factors, we hypothesized that the maturation of tissues during metamorphosis should be preceded by significant modifications in the transcriptome. Targeting the unique metamorphosis of flatfish and taking advantage of the large size of Atlantic halibut (Hippoglossus hippoglossus) larvae, we determined the molecular basis of TH action using RNA sequencing. RESULTS De novo assembly of sequences for larval head, skin and gastrointestinal tract (GI-tract) yielded 90,676, 65,530 and 38,426 contigs, respectively. More than 57 % of the assembled sequences were successfully annotated using a multi-step Blast approach. A unique set of biological processes and candidate genes were identified specifically associated with changes in morphology and function of the head, skin and GI-tract. Transcriptome dynamics during metamorphosis were mapped with SOLiD sequencing of whole larvae and revealed greater than 8,000 differentially expressed (DE) genes significantly (p < 0.05) up- or down-regulated in comparison with the juvenile stage. Candidate transcripts quantified by SOLiD and qPCR analysis were significantly (r = 0.843; p < 0.05) correlated. The majority (98 %) of DE genes during metamorphosis were not TH-responsive. TH-responsive transcripts clustered into 6 groups based on their expression pattern during metamorphosis and the majority of the 145 DE TH-responsive genes were down-regulated. CONCLUSIONS A transcriptome resource has been generated for metamorphosing Atlantic halibut and over 8,000 DE transcripts per stage were identified. Unique sets of biological processes and candidate genes were associated with changes in the head, skin and GI-tract during metamorphosis. A small proportion of DE transcripts were TH-responsive, suggesting that they trigger gene networks, signalling cascades and transcription factors, leading to the overt changes in tissue occurring during metamorphosis.
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Affiliation(s)
- Ricardo N Alves
- Comparative Endocrinology and Integrative Biology Group, Centro de Ciências do Mar - CCMAR, University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
| | - Ana S Gomes
- Department of Biology, University of Bergen, 5020, Bergen, Norway
| | - Kurt Stueber
- Max Planck-Genome Centre, Max Planck-Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, D-50829, Köln, Germany
| | - Mbaye Tine
- Max Planck-Genome Centre, Max Planck-Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, D-50829, Köln, Germany.,Current address: Molecular Zoology Laboratory, Department of Zoology, University of Johannesburg, Auckland Park, 2006, South Africa
| | - M A S Thorne
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | | | - Richard Reinhard
- Max Planck-Genome Centre, Max Planck-Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, D-50829, Köln, Germany
| | - M S Clark
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Ivar Rønnestad
- Department of Biology, University of Bergen, 5020, Bergen, Norway
| | - Deborah M Power
- Comparative Endocrinology and Integrative Biology Group, Centro de Ciências do Mar - CCMAR, University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal.
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