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Yang TY, Zhu ZY, Liu YP, Wang SG. The First Genome-Wide Survey of Shortbelly Eel (Dysomma anguillare Barnard, 1923) to Provide Genomic Characteristics, Microsatellite Markers and Complete Mitogenome Information. Biochem Genet 2024; 62:2296-2313. [PMID: 37906301 DOI: 10.1007/s10528-023-10543-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 10/02/2023] [Indexed: 11/02/2023]
Abstract
Dysomma anguillare is a demersal eel widespread distributing in tropical waters of the Indo-West Pacific and Atlantic. As an important component of the coastal fishery and marine ecosystem, the lack of genomic information for this species severely restricts the progress of relevant researches. In this study, the abecedarian genome-wide characteristics and phylogenetic relationships analyses were carried out based on next-generation sequencing (NGS) platform. The revised genome size was approximately 1 310 Mb, with the largest scaffold length reaching 23 878 bp through K-mer (K = 17) method. The heterozygosity, repetitive rate and average GC content were about 0.94%, 51.93% and 42.23%, respectively. A total of 1 160 104 microsatellite motifs were identified from the de novo assembled genome of D. anguillare, in which dinucleotide repeats accounted for the largest proportion (592 234, 51.05%), the highest occurrence frequency (14.58%) as well as the largest relative abundance (379.27/Mb). The high-polymorphic and moderate-polymorphic loci composed around 73% of the total single sequence repeats (SSRs), showing a latent capacity for subsequent population genetic structure and genetic diversity appraisal researches. Another byproduct of whole-genome sequencing, the double-stranded and circular mitogenome (16 690 bp) was assembled to investigate the evolutionary relationships of D. anguillare. The phylogenic tree constructed with maximum likelihood (ML) method showed that D. anguillare was closely related to Synaphobranchidae species, and the molecular systematic results further supported classical taxonomy status of D. anguillare.
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Affiliation(s)
- Tian-Yan Yang
- Fishery College, Zhejiang Ocean University, Zhoushan, 316022, Zhejiang, China.
| | - Zi-Yan Zhu
- Fishery College, Zhejiang Ocean University, Zhoushan, 316022, Zhejiang, China
| | - Yu-Ping Liu
- Fishery College, Zhejiang Ocean University, Zhoushan, 316022, Zhejiang, China
| | - Si-Ge Wang
- Fishery College, Zhejiang Ocean University, Zhoushan, 316022, Zhejiang, China
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Ferrão L, Blanes-García M, Pérez L, Asturiano JF, Morini M. Superoxidase dismutases (SODs) in the European eel: Gene characterization, expression response to temperature combined with hormonal maturation and possible migratory implications. Comp Biochem Physiol A Mol Integr Physiol 2024; 290:111590. [PMID: 38281705 DOI: 10.1016/j.cbpa.2024.111590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/25/2024] [Accepted: 01/25/2024] [Indexed: 01/30/2024]
Abstract
Superoxide dismutases (SODs) are antioxidant enzymes that protect cells from oxidation. Three SODs have been identified in mammals, but there is limited information in teleosts. This study investigates SODs in the European eel and their expression patterns during testis maturation. Phylogenetic and synteny analyses revealed SODs paralogs and their evolution in vertebrates. The eel possesses one SOD1 and two SOD2/3 (a and b), indicating SOD2 and SOD3 duplication in elopomorphs. SODs expression were then evaluated in various male and female tissues. SOD1 is more expressed in females, while SOD2a and SOD2b dominate brain-pituitary-gonad tissues in both sexes. SOD3a showed predominant expression in the ovary and the male livers, whereas SOD3b was found in the pituitary and brain of both sexes. The effects of different maturation protocols (standard hormonal treatment vs. same protocol preceded with cold seawater pre-treatment) on SODs expression during testis maturation were evaluated. Salinity increase at the onset of standard treatment at 20 °C, simulating early migration, upregulated SOD1, SOD2a, and SOD2b, coinciding with spermatogonia type A differentiated cells dominance. Thereafter, SOD2a and SOD3a decreased, while SOD2b increased during hormonal treatment-induced spermatogenesis. Pre-treatment with seawater at 10 °C, mimicking the conditions at the beginning of the seawater migration, downregulated SOD1 but increased SOD3a expression. Finally, the standard hormonal treatment, replicating spawning at higher temperatures, downregulated SOD1 in eels without any pre-treatment while SOD2a expression increased in pre-treated eels. This study revealed tissue-specific, sex-dependent, and maturation-related SOD expression patterns, predicting SODs dynamic expression profiles during their reproductive migration.
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Affiliation(s)
- L Ferrão
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain
| | - M Blanes-García
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain
| | - L Pérez
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain
| | - J F Asturiano
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain
| | - M Morini
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain.
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Zhu Z, Liu Y, Zhang S, Wang S, Yang T. Genomic microsatellite characteristics analysis of Dysommaanguillare (Anguilliformes, Dysommidae), based on high-throughput sequencing technology. Biodivers Data J 2023; 11:e100068. [PMID: 38327339 PMCID: PMC10848815 DOI: 10.3897/bdj.11.e100068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/31/2023] [Indexed: 02/09/2024] Open
Abstract
Microsatellite loci were screened from the genomic data of Dysommaanguillare and their composition and distribution were analysed by bioinformatics for the first time. The results showed that 4,060,742 scaffolds with a total length of 1,562 Mb were obtained by high-throughput sequencing and 1,160,104 microsatellite loci were obtained by MISA screening, which were distributed on 770,294 scaffolds. The occurrence frequency and relative abundance were 28.57% and 743/Mb, respectively. Amongst the six complete microsatellite types, dinucleotide repeats accounted for the largest proportion (592,234, 51.05%), the highest occurrence frequency (14.58%) and the largest relative abundance (379.27/Mb). A total of 1488 microsatellite repeats were detected in the genome of D.anguillare, amongst which the hexanucleotide repeat motifs were the most abundant (608), followed by pentanucleotide repeat motifs (574), tetranucleotide repeat motifs (232), trinucleotide repeat motifs (59), dinucleotide repeat motifs (11) and mononucleotide repeat motifs (4). The abundance of microsatellites of the same repeat type decreased with the increase of copy numbers. Amongst the six types of nucleotide repeats, the preponderance of repeated motifs are A (191,390, 43.77%), CA (150,240, 25.37%), AAT (13,168, 14.05%), CACG (2,649, 8.14%), TAATG (119, 19.16%) and CCCTAA (190, 19.16%, 7.65%), respectively. The data of the number, distribution and abundance of different types of microsatellites in the genome of D.anguillare were obtained in this study, which would lay a foundation for the development of high-quality microsatellite markers of D.anguillare in the future.
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Affiliation(s)
- Ziyan Zhu
- Zhejiang Ocean University, Zhoushan, ChinaZhejiang Ocean UniversityZhoushanChina
| | - Yuping Liu
- Zhejiang Ocean University, Zhoushan, ChinaZhejiang Ocean UniversityZhoushanChina
| | - Shufei Zhang
- Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Guangzhou, ChinaGuangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research InstituteGuangzhouChina
| | - Sige Wang
- Zhejiang Ocean University, Zhoushan, ChinaZhejiang Ocean UniversityZhoushanChina
| | - Tianyan Yang
- Zhejiang Ocean University, Zhoushan, ChinaZhejiang Ocean UniversityZhoushanChina
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Wang H, Wan HT, Wu B, Jian J, Ng AHM, Chung CYL, Chow EYC, Zhang J, Wong AOL, Lai KP, Chan TF, Zhang EL, Wong CKC. A Chromosome-level assembly of the Japanese eel genome, insights into gene duplication and chromosomal reorganization. Gigascience 2022; 11:giac120. [PMID: 36480030 PMCID: PMC9730501 DOI: 10.1093/gigascience/giac120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/26/2022] [Accepted: 11/15/2022] [Indexed: 12/13/2022] Open
Abstract
Japanese eels (Anguilla japonica) are commercially important species, harvested extensively for food. Currently, this and related species (American and European eels) are challenging to breed on a commercial basis. As a result, the wild stock is used for aquaculture. Moreover, climate change, habitat loss, water pollution, and altered ocean currents affect eel populations negatively. Accordingly, the International Union for Conservation of Nature lists Japanese eels as endangered and on its red list. Here we presented a high-quality genome assembly for Japanese eels and demonstrated that large chromosome reorganizations occurred in the events of third-round whole-genome duplications (3R-WRDs). Several chromosomal fusions and fissions have reduced the ancestral protochromosomal number of 25 to 19 in the Anguilla lineage. A phylogenetic analysis of the expanded gene families showed that the olfactory receptors (group δ and ζ genes) and voltage-gated Ca2+ channels expanded significantly. Both gene families are crucial for olfaction and neurophysiology. Additional tandem and proximal duplications occurred following 3R-WGD to acquire immune-related genes for an adaptive advantage against various pathogens. The Japanese eel assembly presented here can be used to study other Anguilla species relating to evolution and conservation.
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Affiliation(s)
- Hongbo Wang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), China
- Department of Computer Science, Hong Kong Baptist University, Hong Kong SAR
| | - Hin Ting Wan
- Department of Biology, Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Hong Kong SAR
| | - Bin Wu
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Jianbo Jian
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Alice H M Ng
- Department of Biology, Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Hong Kong SAR
| | - Claire Yik-Lok Chung
- School of Life Sciences, State Key Laboratory of Agrobiotechnology, Hong Kong Bioinformatics Centre, the Chinese University of Hong Kong, Hong Kong SAR
| | - Eugene Yui-Ching Chow
- School of Life Sciences, State Key Laboratory of Agrobiotechnology, Hong Kong Bioinformatics Centre, the Chinese University of Hong Kong, Hong Kong SAR
| | - Jizhou Zhang
- School of Life Sciences, State Key Laboratory of Agrobiotechnology, Hong Kong Bioinformatics Centre, the Chinese University of Hong Kong, Hong Kong SAR
| | - Anderson O L Wong
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), China
- School of Biological Sciences, the University of Hong Kong, Hong Kong SAR
| | - Keng Po Lai
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), China
- Key Laboratory of Environmental Pollution and Integrative Omics, Guilin Medical University, Guilin, China
| | - Ting Fung Chan
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), China
- School of Life Sciences, State Key Laboratory of Agrobiotechnology, Hong Kong Bioinformatics Centre, the Chinese University of Hong Kong, Hong Kong SAR
| | - Eric Lu Zhang
- Department of Computer Science, Hong Kong Baptist University, Hong Kong SAR
| | - Chris Kong-Chu Wong
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), China
- Department of Biology, Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Hong Kong SAR
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Ozernyuk N, Schepetov D. HOX-Gene Cluster Organization and Genome Duplications in Fishes and Mammals: Transcript Variant Distribution along the Anterior–Posterior Axis. Int J Mol Sci 2022; 23:ijms23179990. [PMID: 36077385 PMCID: PMC9456325 DOI: 10.3390/ijms23179990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 11/16/2022] Open
Abstract
Hox genes play a crucial role in morphogenesis, especially in anterior–posterior body axis patterning. The organization of Hox clusters in vertebrates is a result of several genome duplications: two rounds of duplication in the ancestors of all vertebrates and a third round that was specific for teleost fishes. Teleostei cluster structure has been significantly modified in the evolutionary processes by Hox gene losses and co-options, while mammals show no such tendency. In mammals, the Hox gene number in a single cluster is stable and generally large, and the numbers are similar to those in the Chondrichthyes. Hox gene alternative splicing activity slightly differs between fishes and mammals. Fishes and mammals have differences in their known alternative splicing activity for Hox gene distribution along the anterior–posterior body axis. The analyzed fish groups—the Coelacanthiformes, Chondrichthyes, and Teleostei—all have higher known alternative mRNA numbers from the anterior and posterior regions, whereas mammals have a more uniform Hox transcript distribution along this axis. In fishes, most Hox transcripts produce functioning proteins, whereas mammals have significantly more known transcripts that do not produce functioning proteins.
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Affiliation(s)
- Nikolay Ozernyuk
- Koltzov Institute of Developmental Biology of Russian Academy of Sciences, 26 Vavilov Street, 119334 Moscow, Russia
- Correspondence:
| | - Dimitry Schepetov
- Faculty of Biology, Lomonosov Moscow State University, 1-12 Leninskie Gory, 119991 Moscow, Russia
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Takei Y, Ando M, Wong MKS, Tsukada T. Molecular mechanisms underlying guanylin-induced transcellular Cl - secretion into the intestinal lumen of seawater-acclimated eels. Gen Comp Endocrinol 2022; 318:113986. [PMID: 35114197 DOI: 10.1016/j.ygcen.2022.113986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 12/20/2021] [Accepted: 01/27/2022] [Indexed: 11/19/2022]
Abstract
Guanylin (GN) stimulates Cl- secretion into the intestinal lumen of seawater-acclimated eels, but the molecular mechanisms of transepithelial Cl- transport are still unknown. In Ussing chamber experiments, we confirmed that mucosal application of eel GN reversed intestinal serosa-negative potential difference, indicating Cl- secretion. Serosal application of DNDS or mucosal application of DPC inhibited the GN effect, but serosal application of bumetanide had no effect. Removal of HCO3- from the serosal fluid also inhibited the GN effect. In intestinal sac experiments, mucosal GN stimulated luminal secretion of both Cl- and Na+, which was blocked by serosal DNDS. These results suggest that Cl- is taken up at the serosal side by DNDS-sensitive anion exchanger (AE) coupled with Na+-HCO3- cotransporter (NBC) but not by Na+-K+-2Cl- cotransporter 1 (NKCC1), and Cl- is secreted by unknown DPC-sensitive Cl- channel (ClC) at the mucosal side. The transcriptomic analysis combined with qPCR showed low expression of NKCC1 gene and no upregulation of the gene after seawater transfer, while high expression of ClC2 gene and upregulation after seawater transfer. In addition, SO42- transporters (apical Slc26a3/6 and basolateral Slc26a1) are also candidates for transcellular Cl- secretion in exchange of luminal SO42. Na+ secretion could occur through a paracellular route, as Na+-leaky claudin15 was highly expressed and upregulated after seawater transfer. High local Na+ concentration in the lateral interspace produced by Na+/K+-ATPase (NKA) coupled with K+ channels (Kir5.1b) seems to facilitate the paracellular transport. In situ hybridization confirmed the expression of the candidate genes in the epithelial enterocytes. Together with our previous results, we suggest that GN stimulates basolateral NBCela/AE2 and apical ClC2 to increase transcellular Cl- secretion in seawater eel intestine, which differs from the involvement of apical CFTR and basolateral NKCC1 as suggested in mammals and other teleosts.
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Affiliation(s)
- Yoshio Takei
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba 277-8564, Japan.
| | - Masaaki Ando
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba 277-8564, Japan
| | - Marty K S Wong
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba 277-8564, Japan
| | - Takehiro Tsukada
- Department of Biomolecular Science, Faculty of Science, Toho University, Funabashi, Chiba 274-8510, Japan
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Duong TA, Aylward J, Ametrano CG, Poudel B, Santana QC, Wilken PM, Martin A, Arun-Chinnappa KS, de Vos L, DiStefano I, Grewe F, Huhndorf S, Lumbsch HT, Rakoma JR, Poudel B, Steenkamp ET, Sun Y, van der Nest MA, Wingfield MJ, Yilmaz N, Wingfield BD. IMA Genome - F15 : Draft genome assembly of Fusarium pilosicola, Meredithiella fracta, Niebla homalea, Pyrenophora teres hybrid WAC10721, and Teratosphaeria viscida. IMA Fungus 2021; 12:30. [PMID: 34645521 PMCID: PMC8513234 DOI: 10.1186/s43008-021-00077-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2021] [Indexed: 12/01/2022] Open
Affiliation(s)
- Tuan Anh Duong
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Janneke Aylward
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
- Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | - Claudio Gennaro Ametrano
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, 1400 S Lake Shore Drive, Chicago, IL 60605, USA
| | - Barsha Poudel
- Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
| | - Quentin Carlo Santana
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Pieter Markus Wilken
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Anke Martin
- Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
| | - Kiruba Shankari Arun-Chinnappa
- Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
- PerkinElmer Pty LTD., Level 2, Building 5, Brandon Business Park 530-540, Springvale Road, Glen Waverley, VIC, 3150, Australia
| | - Lieschen de Vos
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Isabel DiStefano
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, 1400 S Lake Shore Drive, Chicago, IL 60605, USA
| | - Felix Grewe
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, 1400 S Lake Shore Drive, Chicago, IL 60605, USA
| | - Sabine Huhndorf
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, 1400 S Lake Shore Drive, Chicago, IL 60605, USA
| | - Helge Thorsten Lumbsch
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, 1400 S Lake Shore Drive, Chicago, IL 60605, USA
| | - Jostina Raesetsa Rakoma
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Barsha Poudel
- Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
| | - Emma Theodora Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Yukun Sun
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, 1400 S Lake Shore Drive, Chicago, IL 60605, USA
| | - Magriet A van der Nest
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
- Biotechnology Platform, Agricultural Research Council, Onderstepoort, Pretoria, 0110, South Africa
| | - Michael John Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Neriman Yilmaz
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Brenda Diana Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa.
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Takei Y. The digestive tract as an essential organ for water acquisition in marine teleosts: lessons from euryhaline eels. ZOOLOGICAL LETTERS 2021; 7:10. [PMID: 34154668 PMCID: PMC8215749 DOI: 10.1186/s40851-021-00175-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 04/16/2021] [Indexed: 05/17/2023]
Abstract
Adaptation to a hypertonic marine environment is one of the major topics in animal physiology research. Marine teleosts lose water osmotically from the gills and compensate for this loss by drinking surrounding seawater and absorbing water from the intestine. This situation is in contrast to that in mammals, which experience a net osmotic loss of water after drinking seawater. Water absorption in fishes is made possible by (1) removal of monovalent ions (desalinization) by the esophagus, (2) removal of divalent ions as carbonate (Mg/CaCO3) precipitates promoted by HCO3- secretion, and (3) facilitation of NaCl and water absorption from diluted seawater by the intestine using a suite of unique transporters. As a result, 70-85% of ingested seawater is absorbed during its passage through the digestive tract. Thus, the digestive tract is an essential organ for marine teleost survival in the hypertonic seawater environment. The eel is a species that has been frequently used for osmoregulation research in laboratories worldwide. The eel possesses many advantages as an experimental animal for osmoregulation studies, one of which is its outstanding euryhalinity, which enables researchers to examine changes in the structure and function of the digestive tract after direct transfer from freshwater to seawater. In recent years, the molecular mechanisms of ion and water transport across epithelial cells (the transcellular route) and through tight junctions (the paracellular route) have been elucidated for the esophagus and intestine. Thanks to the rapid progress in analytical methods for genome databases on teleosts, including the eel, the molecular identities of transporters, channels, pumps and junctional proteins have been clarified at the isoform level. As 10 y have passed since the previous reviews on this subject, it seems relevant and timely to summarize recent progress in research on the molecular mechanisms of water and ion transport in the digestive tract in eels and to compare the mechanisms with those of other teleosts and mammals from comparative and evolutionary viewpoints. We also propose future directions for this research field to achieve integrative understanding of the role of the digestive tract in adaptation to seawater with regard to pathways/mechanisms including the paracellular route, divalent ion absorption, metabolon formation and cellular trafficking of transporters. Notably, some of these have already attracted practical attention in laboratories.
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Affiliation(s)
- Yoshio Takei
- Laboratory of Physiology, Department of Marine Bioscience, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan.
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Lin CJ, Maugars G, Lafont AG, Jeng SR, Wu GC, Dufour S, Chang CF. Basal teleosts provide new insights into the evolutionary history of teleost-duplicated aromatase. Gen Comp Endocrinol 2020; 291:113395. [PMID: 31981691 DOI: 10.1016/j.ygcen.2020.113395] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 01/04/2020] [Accepted: 01/20/2020] [Indexed: 11/25/2022]
Abstract
Duplicated cyp19a1 genes (cyp19a1a encoding aromatase a and cyp19a1b encoding aromatase b) have been identified in an increasing number of teleost species. Cyp19a1a is mainly expressed in the gonads, while cyp19a1b is mainly expressed in the brain, specifically in radial glial cells, as largely investigated by Kah and collaborators. The third round of whole-genome duplication that specifically occurred in the teleost lineage (TWGD or 3R) is likely at the origin of the duplicated cyp19a1 paralogs. In contrast to the situation in other teleosts, our previous studies identified a single cyp19a1 in eels (Anguilla), which are representative species of a basal group of teleosts, Elopomorpha. In the present study, using genome data mining and phylogenetic and synteny analyses, we confirmed that the whole aromatase genomic region was duplicated in eels, with most aromatase-neighboring genes being conserved in duplicate in eels, as in other teleosts. These findings suggest that specific gene loss of one of the 3R-duplicated cyp19a1 paralogs occurred in Elopomorpha after TWGD. Similarly, a single cyp19a1 gene was found in the arowana, which is a representative species of another basal group of teleosts, Osteoglossomorpha. In eels, the single cyp19a1 is expressed in both the brain and the gonads, as observed for the single CYP19A1 gene present in other vertebrates. The results of phylogenetic, synteny, closest neighboring gene, and promoter structure analyses showed that the single cyp19a1 of the basal teleosts shared conserved properties with both teleost cyp19a1a and cyp19a1b paralogs, which did not allow us to conclude which of the 3R-duplicated paralogs (cyp19a1a or cyp19a1b) was lost in Elopomorpha. Elopomorpha and Osteoglossomorpha cyp19a1 genes exhibited preserved ancestral functions, including expression in both the gonad and brain. We propose that the subfunctionalization of the 3R-duplicated cyp19a1 paralogs expressed specifically in the gonad or brain occurred in Clupeocephala, after the split of Clupeocephala from Elopomorpha and Osteoglossomorpha, which represented a driving force for the conservation of both 3R-duplicated paralogs in all extant Clupeocephala. In contrast, the functional redundancy of the undifferentiated 3R-duplicated cyp19a1 paralogs in elopomorphs and osteoglossomorphs would have favored the loss of one 3R paralog in basal teleosts.
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Affiliation(s)
- Chien-Ju Lin
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Gersende Maugars
- Laboratory Biology of Aquatic Organisms and Ecosystems (BOREA), Muséum National d'Histoire Naturelle, CNRS, IRD, Sorbonne Université, Université de Caen Normandie, Université des Antilles, 75231 Paris Cedex 05, France
| | - Anne-Gaëlle Lafont
- Laboratory Biology of Aquatic Organisms and Ecosystems (BOREA), Muséum National d'Histoire Naturelle, CNRS, IRD, Sorbonne Université, Université de Caen Normandie, Université des Antilles, 75231 Paris Cedex 05, France
| | - Shan-Ru Jeng
- Department of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung 811, Taiwan
| | - Guan-Chung Wu
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Sylvie Dufour
- Laboratory Biology of Aquatic Organisms and Ecosystems (BOREA), Muséum National d'Histoire Naturelle, CNRS, IRD, Sorbonne Université, Université de Caen Normandie, Université des Antilles, 75231 Paris Cedex 05, France.
| | - Ching-Fong Chang
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan.
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10
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Barth JMI, Gubili C, Matschiner M, Tørresen OK, Watanabe S, Egger B, Han YS, Feunteun E, Sommaruga R, Jehle R, Schabetsberger R. Stable species boundaries despite ten million years of hybridization in tropical eels. Nat Commun 2020; 11:1433. [PMID: 32188850 PMCID: PMC7080837 DOI: 10.1038/s41467-020-15099-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 02/07/2020] [Indexed: 02/01/2023] Open
Abstract
Genomic evidence is increasingly underpinning that hybridization between taxa is commonplace, challenging our views on the mechanisms that maintain their boundaries. Here, we focus on seven catadromous eel species (genus Anguilla) and use genome-wide sequence data from more than 450 individuals sampled across the tropical Indo-Pacific, morphological information, and three newly assembled draft genomes to compare contemporary patterns of hybridization with signatures of past introgression across a time-calibrated phylogeny. We show that the seven species have remained distinct for up to 10 million years and find that the current frequencies of hybridization across species pairs contrast with genomic signatures of past introgression. Based on near-complete asymmetry in the directionality of hybridization and decreasing frequencies of later-generation hybrids, we suggest cytonuclear incompatibilities, hybrid breakdown, and purifying selection as mechanisms that can support species cohesion even when hybridization has been pervasive throughout the evolutionary history of clades.
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Affiliation(s)
- Julia M I Barth
- Department of Environmental Sciences, Zoological Institute, University of Basel, Vesalgasse 1, 4051, Basel, Switzerland
| | - Chrysoula Gubili
- Fisheries Research Institute, Hellenic Agricultural Organisation-DEMETER, Nea Peramos, 64 007, Kavala, Greece
| | - Michael Matschiner
- Department of Palaeontology and Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006, Zurich, Switzerland.
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316, Oslo, Norway.
| | - Ole K Tørresen
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316, Oslo, Norway
| | - Shun Watanabe
- Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara, 631-8505, Japan
| | - Bernd Egger
- Department of Environmental Sciences, Zoological Institute, University of Basel, Vesalgasse 1, 4051, Basel, Switzerland
| | - Yu-San Han
- Institute of Fisheries Science, College of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Eric Feunteun
- Laboratoire Biologie des Organismes et Écosystèmes Aquatiques (BOREA), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, Université de Caen Normandie, Université des Antilles, IRD, 61 Rue Buffon, CP 53, 75231, Paris Cedex 05, France
- MNHN-Station Marine de Dinard, Centre de Recherche et d'Enseignement Sur les Systèmes Côtiers (CRESCO), 38 Rue du Port Blanc, 35800, Dinard, France
| | - Ruben Sommaruga
- Department of Ecology, University of Innsbruck, Technikerstr. 25, 6020, Innsbruck, Austria
| | - Robert Jehle
- School of Science, Engineering and Environment, University of Salford, Salford Crescent, Salford, M5 4WT, UK.
| | - Robert Schabetsberger
- Department of Biosciences, University of Salzburg, Hellbrunnerstrasse 34, 5020, Salzburg, Austria.
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11
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Mikalsen SO, Tausen M, Í Kongsstovu S. Phylogeny of teleost connexins reveals highly inconsistent intra- and interspecies use of nomenclature and misassemblies in recent teleost chromosome assemblies. BMC Genomics 2020; 21:223. [PMID: 32160866 PMCID: PMC7066803 DOI: 10.1186/s12864-020-6620-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/25/2020] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Based on an initial collecting of database sequences from the gap junction protein gene family (also called connexin genes) in a few teleosts, the naming of these sequences appeared variable. The reasons could be (i) that the structure in this family is variable across teleosts, or (ii) unfortunate naming. Rather clear rules for the naming of genes in fish and mammals have been outlined by nomenclature committees, including the naming of orthologous and ohnologous genes. We therefore analyzed the connexin gene family in teleosts in more detail. We covered the range of divergence times in teleosts (eel, Atlantic herring, zebrafish, Atlantic cod, three-spined stickleback, Japanese pufferfish and spotted pufferfish; listed from early divergence to late divergence). RESULTS The gene family pattern of connexin genes is similar across the analyzed teleosts. However, (i) several nomenclature systems are used, (ii) specific orthologous groups contain genes that are named differently in different species, (iii) several distinct genes have the same name in a species, and (iv) some genes have incorrect names. The latter includes a human connexin pseudogene, claimed as GJA4P, but which in reality is Cx39.2P (a delta subfamily gene often called GJD2like). We point out the ohnologous pairs of genes in teleosts, and we suggest a more consistent nomenclature following the outlined rules from the nomenclature committees. We further show that connexin sequences can indicate some errors in two high-quality chromosome assemblies that became available very recently. CONCLUSIONS Minimal consistency exists in the present practice of naming teleost connexin genes. A consistent and unified nomenclature would be an advantage for future automatic annotations and would make various types of subsequent genetic analyses easier. Additionally, roughly 5% of the connexin sequences point out misassemblies in the new high-quality chromosome assemblies from herring and cod.
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Affiliation(s)
- Svein-Ole Mikalsen
- Faculty of Science and Technology, University of the Faroe Islands, Vestara Bryggja 15, FO-100, Tórshavn, Faroe Islands.
| | - Marni Tausen
- Faculty of Science and Technology, University of the Faroe Islands, Vestara Bryggja 15, FO-100, Tórshavn, Faroe Islands
- Present affiliation: Bioinformatics Research Centre, Aarhus University, C. F. Møllers Allé 8, 8000, Aarhus C, Denmark
| | - Sunnvør Í Kongsstovu
- Faculty of Science and Technology, University of the Faroe Islands, Vestara Bryggja 15, FO-100, Tórshavn, Faroe Islands
- Amplexa Genetics A/S, Hoyvíksvegur 51, FO-100, Tórshavn, Faroe Islands
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12
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Maugars G, Pasquier J, Atkinson C, Lafont AG, Campo A, Kamech N, Lefranc B, Leprince J, Dufour S, Rousseau K. Gonadotropin-inhibitory hormone in teleosts: New insights from a basal representative, the eel. Gen Comp Endocrinol 2020; 287:113350. [PMID: 31794732 DOI: 10.1016/j.ygcen.2019.113350] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 11/26/2019] [Accepted: 11/27/2019] [Indexed: 12/11/2022]
Abstract
Since its discovery in birds, gonadotropin-inhibitory hormone (GnIH) has triggered investigation in the other groups of vertebrates. In the present study, we have identified a single gnih gene in the European eel (Anguilla anguilla), a representative species of a basal group of teleosts (Elopomorphs). We have also retrieved a single gnih gene in Osteoglossomorphs, as well as in more recently emerged teleosts, Clupeocephala. Phylogeny and synteny analyses allowed us to infer that one of the two gnih paralogs emerged from the teleost-specific whole genome duplication (TWGD or 3R), would have been lost shortly after the 3R, before the emergence of the basal groups of teleosts. This led to the presence of a single gnih in extant teleosts as in other vertebrates. Two gnih paralogs were still found in some teleost species, such as in salmonids, but resulting from the additional whole genome duplication that specifically occurred in this lineage (4R). Eel gnih was mostly expressed in the diencephalon part of the brain, as analyzed by quantitative real-time PCR. Cloning of eel gnih cDNA confirmed that the sequence of the GnIH precursor encoded three putative mature GnIH peptides (aaGnIH-1, aaGnIH-2 and aaGnIH-3), which were synthesized and tested for their direct effects on eel pituitary cells in vitro. Eel GnIH peptides inhibited the expression of gonadotropin subunits (lhβ, fshβ, and common a-subunit) as well as of GnRH receptor (gnrh-r2), with no effect on tshβ and gh expression. The inhibitory effect of GnIH peptides on gonadotropic function in a basal teleost is in agreement with an ancestral inhibitory role of GnIH in the neuroendocrine control of reproduction in vertebrates.
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Affiliation(s)
- G Maugars
- Muséum National d'Histoire Naturelle, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, SU, UCN, UA, Paris, France
| | - J Pasquier
- Muséum National d'Histoire Naturelle, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, SU, UCN, UA, Paris, France
| | - C Atkinson
- Muséum National d'Histoire Naturelle, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, SU, UCN, UA, Paris, France
| | - A-G Lafont
- Muséum National d'Histoire Naturelle, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, SU, UCN, UA, Paris, France
| | - A Campo
- Muséum National d'Histoire Naturelle, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, SU, UCN, UA, Paris, France
| | - N Kamech
- Muséum National d'Histoire Naturelle, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, SU, UCN, UA, Paris, France
| | - B Lefranc
- Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, INSERM U1239, Normandy University, Rouen, France
| | - J Leprince
- Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, INSERM U1239, Normandy University, Rouen, France
| | - S Dufour
- Muséum National d'Histoire Naturelle, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, SU, UCN, UA, Paris, France
| | - K Rousseau
- Muséum National d'Histoire Naturelle, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, SU, UCN, UA, Paris, France.
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13
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Identification and stable expression of vitellogenin receptor through vitellogenesis in the European eel. Animal 2020; 14:1213-1222. [PMID: 31971122 DOI: 10.1017/s1751731119003355] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In teleosts, vitellogenin (Vtg) is a phospholipoglycoprotein synthesized by the liver, released into the blood circulation and incorporated into the oocytes via endocytosis mediated by the Vtg receptor (VTGR) to form the yolk granules. The VTGR is crucial for oocyte growth in egg-laying animals but is also present in non-oviparous vertebrates, such as human. The VTGR belongs to the low-density lipoprotein receptor superfamily (LDLR) and is also named very-low-density lipoprotein receptor (VLDLR). In this study, we identified and phylogenetically positioned the VTGR of a basal teleost, the European eel, Anguilla anguilla. We developed quantitative real-time PCR (qRT-PCR) and investigated the tissue distribution of vtgr transcripts. We compared by qRT-PCR the ovarian expression levels of vtgr in juvenile yellow eels and pre-pubertal silver eels. We also analyzed the regulation of ovarian vtgr expression throughout vitellogenesis in experimentally matured eels. The Vtg plasma level was measured by homologous ELISA experimental maturation. Our in silico search and phylogenetical analysis revealed a single vtgr in the European eel, orthologous to other vertebrate vtgr. The qRT-PCR studies revealed that vtgr is mainly expressed in the ovary and also detected in various other tissues such as brain, pituitary, gill, fat, heart, and testis, suggesting some extra-ovarian functions of VTGR. We showed that vtgr is expressed in ovaries of juvenile yellow eels with no higher expression in pre-pubertal silver eels nor in experimentally matured eels. This suggests that vtgr transcription already occurs during early pre-vitellogenesis of immature eels and is not further activated in vitellogenic oocytes. European eel Vtg plasma level increased throughout experimental maturation in agreement with previous studies. Taken together, these results suggest that vtgr transcript levels may not be a limiting step for the uptake of Vtg by the oocyte in the European eel.
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14
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Suzuki H, Kazeto Y, Gen K, Ozaki Y. Functional analysis of recombinant single-chain Japanese eel Fsh and Lh produced in FreeStyle 293-F cell lines: Binding specificities to their receptors and differential efficacy on testicular steroidogenesis. Gen Comp Endocrinol 2020; 285:113241. [PMID: 31400434 DOI: 10.1016/j.ygcen.2019.113241] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 07/11/2019] [Accepted: 08/06/2019] [Indexed: 01/02/2023]
Abstract
Pituitary gonadotropins, follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh), play central roles in the control of gonadal development of vertebrates. In mammals, Fsh and Lh exclusively activate their respective cognate receptors: Fsh receptor (Fshr) in the Sertoli cell and Lh/choriogonadotropin receptor (Lhcgr) in the Leydig cell. In teleosts, the distinct functions of Fsh and Lh and information on cellular localization of their receptors are still poorly understood. Recently we established FreeStyle 293-F cell lines producing recombinant Japanese eel Fsh and Lh (reFsh and reLh), which form a single chain consisting of a common α-subunit and β-subunits. In this study, we conducted functional analyses of reFsh and reLh, focusing on the binding specificities to their receptors and effects on testicular steroidogenesis in vitro. Assays with gonadotropin receptors-expressing COS-7 cells indicated reFsh stimulated its cognate receptor, meanwhile reLh activated both receptors. Although results of in vitro incubations showed that reFsh and reLh induced testicular 11-ketotestosterone production in a dose and time-dependent manner by upregulating expression of steroidogenic enzymes, the effective doses of reLh were apparently lower and the effects of reLh emerged faster in comparison with reFsh. Results of quantitative real-time PCR using testicular cell fractions showed that fshr and lhcgr1 mRNA were detected both in Sertoli and Leydig cells. These analyses revealed that reFsh and reLh were biologically active and hence will be useful for future studies. Moreover, our data showed that both eel Fsh and Lh acted as steroidogenic hormones through their receptors in testicular somatic cells; however, Lh was more potent on androgen production, implying differential functions on spermatogenesis.
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Affiliation(s)
- Hiroshi Suzuki
- Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan; National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, 224-1 Hiruda, Tamaki, Watarai, Mie 519-0423, Japan.
| | - Yukinori Kazeto
- National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Tsuiura, Kamiura, Saiki, Oita 879-2602, Japan.
| | - Koichiro Gen
- Seikai National Fisheries Research Institute, Japan Fisheries Research and Education Agency, 1551-8 Taira, Nagasaki 851-2213, Japan.
| | - Yuichi Ozaki
- National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, 224-1 Hiruda, Tamaki, Watarai, Mie 519-0423, Japan.
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15
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Dufour S, Quérat B, Tostivint H, Pasqualini C, Vaudry H, Rousseau K. Origin and Evolution of the Neuroendocrine Control of Reproduction in Vertebrates, With Special Focus on Genome and Gene Duplications. Physiol Rev 2019; 100:869-943. [PMID: 31625459 DOI: 10.1152/physrev.00009.2019] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In humans, as in the other mammals, the neuroendocrine control of reproduction is ensured by the brain-pituitary gonadotropic axis. Multiple internal and environmental cues are integrated via brain neuronal networks, ultimately leading to the modulation of the activity of gonadotropin-releasing hormone (GnRH) neurons. The decapeptide GnRH is released into the hypothalamic-hypophysial portal blood system and stimulates the production of pituitary glycoprotein hormones, the two gonadotropins luteinizing hormone and follicle-stimulating hormone. A novel actor, the neuropeptide kisspeptin, acting upstream of GnRH, has attracted increasing attention in recent years. Other neuropeptides, such as gonadotropin-inhibiting hormone/RF-amide related peptide, and other members of the RF-amide peptide superfamily, as well as various nonpeptidic neuromediators such as dopamine and serotonin also provide a large panel of stimulatory or inhibitory regulators. This paper addresses the origin and evolution of the vertebrate gonadotropic axis. Brain-pituitary neuroendocrine axes are typical of vertebrates, the pituitary gland, mediator and amplifier of brain control on peripheral organs, being a vertebrate innovation. The paper reviews, from molecular and functional perspectives, the evolution across vertebrate radiation of some key actors of the vertebrate neuroendocrine control of reproduction and traces back their origin along the vertebrate lineage and in other metazoa before the emergence of vertebrates. A focus is given on how gene duplications, resulting from either local events or from whole genome duplication events, and followed by paralogous gene loss or conservation, might have shaped the evolutionary scenarios of current families of key actors of the gonadotropic axis.
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Affiliation(s)
- Sylvie Dufour
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Bruno Quérat
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Hervé Tostivint
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Catherine Pasqualini
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Hubert Vaudry
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Karine Rousseau
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
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16
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Daily variation of D2 dopamine receptor transcription in the brain of the Japanese eel Anguilla japonica and its regulation with dopamine and melatonin. Comp Biochem Physiol A Mol Integr Physiol 2019; 240:110581. [PMID: 31634572 DOI: 10.1016/j.cbpa.2019.110581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/31/2019] [Accepted: 09/17/2019] [Indexed: 11/22/2022]
Abstract
Dopamine plays a crucial role in controlling reproduction in eels, and its action is mediated through D2-type dopamine receptors. D2A and D2B receptors in the Japanese eel Anguilla japonica were cloned and characterized in the present study. Attention (daily expression patterns in the brain and endogenous regulation) was paid to D2B receptor because it is considered to play a crucial role in eel reproduction. The cDNAs of D2A and D2B receptors had open reading frames comprising 456 and 454 amino acid residues, respectively, which were phylogenetically clustered with those of other teleost species. Both receptors were highly expressed in the brain. D2B receptor transcript levels exhibited high day/low night variation in the midbrain and pituitary, suggesting that its transcription in these tissues is regulated in a daily manner, possibly under influence of melatonin. Intraperitoneal injection of dopamine downregulated D2B receptor transcription significantly in the midbrain and moderately in the pituitary within 1 h, but upregulated its transcription in the forebrain. Co-injection of dopamine with its antagonist (domperidone) reversed the effect of dopamine in the pituitary and forebrain, but not in the midbrain, suggesting that the effect of dopamine on D2B receptor transcription differs among brain regions. The same treatment with melatonin resulted in decreased D2B receptor transcription in the midbrain. These findings indicate that dopamine and melatonin have key roles in the daily variation in D2B receptor transcription in the brain of Japanese eel, and that they are related to a daily base secretion of hormones in the hypothalamic-pituitary-gonadal axis in this species.
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17
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Izumi H, Gen K, Lokman PM, Hagihara S, Horiuchi M, Tanaka T, Ijiri S, Adachi S. Maternal transcripts in good and poor quality eggs from Japanese eel,
Anguilla japonica
—their identification by large‐scale quantitative analysis. Mol Reprod Dev 2019; 86:1846-1864. [DOI: 10.1002/mrd.23273] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 08/29/2019] [Indexed: 01/16/2023]
Affiliation(s)
- Hikari Izumi
- Division of Marine Life ScienceHokkaido University Hokkaido Japan
| | - Koichiro Gen
- Seikai National Fisheries Research InstituteFisheries Research Agency Nagasaki Japan
| | - P. Mark Lokman
- Department of ZoologyUniversity of Otago Dunedin New Zealand
| | - Seishi Hagihara
- Division of Marine Life ScienceHokkaido University Hokkaido Japan
| | - Moemi Horiuchi
- Division of Marine Life ScienceHokkaido University Hokkaido Japan
| | - Toshiomi Tanaka
- Hamanako BranchShizuoka Prefectural Research Institute of Fishery Shizuoka Japan
| | - Shigeho Ijiri
- Division of Marine Life ScienceHokkaido University Hokkaido Japan
| | - Shinji Adachi
- Division of Marine Life ScienceHokkaido University Hokkaido Japan
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18
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Divergence, evolution and adaptation in ray-finned fish genomes. SCIENCE CHINA-LIFE SCIENCES 2019; 62:1003-1018. [PMID: 31098893 DOI: 10.1007/s11427-018-9499-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 02/12/2019] [Indexed: 02/06/2023]
Abstract
With the rapid development of next-generation sequencing technologies and bioinformatics, over 50 ray-finned fish genomes by far have been sequenced with high quality. The genomic work provides abundant genetic resources for deep understanding of divergence, evolution and adaptation in the fish genomes. They are also instructive for identification of candidate genes for functional verification, molecular breeding, and development of novel marine drugs. As an example of other omics data, the Fish-T1K project generated a big database of fish transcriptomes to integrate with these published fish genomes for potential applications. In this review, we highlight the above-mentioned recent investigations and core topics on the ray-finned fish genome research, with a main goal to obtain a deeper understanding of fish biology for theoretical and practical applications.
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19
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Hyeon JY, Hur SP, Kim BH, Byun JH, Kim ES, Lim BS, Lee BI, Kim SK, Takemura A, Kim SJ. Involvement of Estrogen and Its Receptors in Morphological Changes in the Eyes of the Japanese Eel, Anguilla japonica, in the Process of Artificially-Induced Maturation. Cells 2019; 8:cells8040310. [PMID: 30987251 PMCID: PMC6526474 DOI: 10.3390/cells8040310] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/21/2019] [Accepted: 03/30/2019] [Indexed: 01/14/2023] Open
Abstract
During the long migration from river habitats to the spawning ground, the Japanese eel undergoes sexual maturation. This spawning migration occurs concurrently with morphological changes, such as increases in eye size; however, the mechanisms by which sex steroids and their receptors influence these changes in peripheral tissues remain unclear. The aim of this study was to investigate changes in the eyes of female Japanese eels during sexual maturation, and our research focused on estrogen receptor (ER)α and ERβ transcripts. During ovarian development, the gonadosomatic index increased and yolk-laden oocytes developed rapidly. These changes occurred in conjunction with a steady increase in plasma levels of estradiol-17β (E2). Concomitant increases in transcript levels of ERα and ERβ in eye, brain, pituitary, and ovary were also observed. Fluorescence in-situ hybridization analyses revealed that ERα and ERβ transcripts were present in the choriocapillary layer and photoreceptor layer of the eyes, and the analysis also revealed that their signals in these layers became stronger in mature females compared to those observed in immature females, suggesting that under the influence of gonadotropins, morphological changes in the eyes are regulated by E2 through the activation of its receptors. In conclusion, E2 plays a crucial role in physiological adaptations that occur in peripheral tissues during the spawning migration.
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Affiliation(s)
- Ji-Yeon Hyeon
- Jeju International Marine Science Research & Logistics Center, Korea Institute of Ocean Science & Technology, 2670 Iljudong-ro, Gujwa, Jeju 63349, Korea.
- Department of Biology, Jeju National University, 102 Jejudaehak-ro, Jeju 63243, Korea.
| | - Sung-Pyo Hur
- Jeju International Marine Science Research & Logistics Center, Korea Institute of Ocean Science & Technology, 2670 Iljudong-ro, Gujwa, Jeju 63349, Korea.
| | - Byeong-Hoon Kim
- Marine Science Institute, Jeju National University, 19-5 Hamdeok 5-gil, Jocheon, Jeju 63333, Korea.
| | - Jun-Hwan Byun
- Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan.
| | - Eun-Su Kim
- Solforto Co. Ltd., 19 Yeondong 8-gil, Jeju 63133, Korea.
| | - Bong-Soo Lim
- Solforto Co. Ltd., 19 Yeondong 8-gil, Jeju 63133, Korea.
| | - Bae-Ik Lee
- Aquaculture Research Division, National Institute of Fisheries Science, 216 Gijanghaean-ro, Gijang, Busan 46083, Korea.
| | - Shin-Kwon Kim
- Aquaculture Research Division, National Institute of Fisheries Science, 216 Gijanghaean-ro, Gijang, Busan 46083, Korea.
| | - Akihiro Takemura
- Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan.
| | - Se-Jae Kim
- Department of Biology, Jeju National University, 102 Jejudaehak-ro, Jeju 63243, Korea.
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Miest JJ, Politis SN, Adamek M, Tomkiewicz J, Butts IAE. Molecular ontogeny of larval immunity in European eel at increasing temperatures. FISH & SHELLFISH IMMUNOLOGY 2019; 87:105-119. [PMID: 30590168 DOI: 10.1016/j.fsi.2018.12.048] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 11/12/2018] [Accepted: 12/23/2018] [Indexed: 06/09/2023]
Abstract
Temperature is a major factor that modulates the development and reactivity of the immune system. Only limited knowledge exists regarding the immune system of the catadromous European eel, Anguilla anguilla, especially during the oceanic early life history stages. Thus, a new molecular toolbox was developed, involving tissue specific characterisation of 3 housekeeping genes, 9 genes from the innate and 3 genes from the adaptive immune system of this species. The spatial pattern of immune genes reflected their function, e.g. complement component c3 was mainly produced in liver and il10 in the head kidney. Subsequently, the ontogeny of the immune system was studied in larvae reared from hatch to first-feeding at four temperatures, spanning their thermal tolerance range (16, 18, 20, and 22 °C). Expression of some genes (c3 and igm) declined post hatch, whilst expression of most other genes (mhc2, tlr2, il1β, irf3, irf7) increased with larval age. At the optimal temperature, 18 °C, this pattern of immune-gene expression revealed an immunocompromised phase between hatch (0 dph) and teeth-development (8 dph). The expression of two of the studied genes (mhc2, lysc) was temperature dependent, leading to increased mRNA levels at 22 °C. Additionally, at the lower end of the thermal spectrum (16 °C) immune competency appeared reduced, whilst close to the upper thermal limit (22 °C) larvae showed signs of thermal stress. Thus, protection against pathogens is probably impaired at temperatures close to the critical thermal maximum (CTmax), impacting survival and productivity in hatcheries and natural recruitment.
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Affiliation(s)
- Joanna J Miest
- Evolutionary Ecology of Marine Fish, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, Germany; School of Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK.
| | - Sebastian N Politis
- National Institute of Aquatic Resources, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Mikolaj Adamek
- Fish Disease Research Unit, Centre of Infectious Diseases, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Jonna Tomkiewicz
- National Institute of Aquatic Resources, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Ian A E Butts
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
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21
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Lack of spatial and temporal genetic structure of Japanese eel (Anguilla japonica) populations. CONSERV GENET 2019. [DOI: 10.1007/s10592-019-01146-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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22
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Nagasawa T, Kawaguchi M, Yano T, Isoyama S, Yasumasu S, Okabe M. Translocation of promoter-conserved hatching enzyme genes with intron-loss provides a new insight in the role of retrocopy during teleostean evolution. Sci Rep 2019; 9:2448. [PMID: 30792427 PMCID: PMC6385490 DOI: 10.1038/s41598-019-38693-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 12/17/2018] [Indexed: 11/12/2022] Open
Abstract
The hatcing enzyme gene (HE) encodes a protease that is indispensable for the hatching process and is conserved during vertebrate evolution. During teleostean evolution, it is known that HE experienced a drastic transfiguration of gene structure, namely, losing all of its introns. However, these facts are contradiction with each other, since intron-less genes typically lose their original promoter because of duplication via mature mRNA, called retrocopy. Here, using a comparative genomic assay, we showed that HEs have changed their genomic location several times, with the evolutionary timings of these translocations being identical to those of intron-loss. We further showed that HEs maintain the promoter sequence upstream of them after translocation. Therefore, teleostean HEs are unique genes which have changed intra- (exon-intron) and extra-genomic structure (genomic loci) several times, although their indispensability for the reproductive process of hatching implies that HE genes are translocated by retrocopy with their promoter sequence.
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Affiliation(s)
- Tatsuki Nagasawa
- Department of Anatomy, The Jikei University School of Medicine, 3-25-8 Nishishimbashi, Minato-ku, Tokyo, 105-8461, Japan.,Research Fellow of the Japan Society for the Promotion of Science (JSPS), Tokyo, 102-0083, Japan.,Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo, 102-8554, Japan
| | - Mari Kawaguchi
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo, 102-8554, Japan
| | - Tohru Yano
- Department of Anatomy, The Jikei University School of Medicine, 3-25-8 Nishishimbashi, Minato-ku, Tokyo, 105-8461, Japan
| | - Sho Isoyama
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo, 102-8554, Japan
| | - Shigeki Yasumasu
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo, 102-8554, Japan.
| | - Masataka Okabe
- Department of Anatomy, The Jikei University School of Medicine, 3-25-8 Nishishimbashi, Minato-ku, Tokyo, 105-8461, Japan
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23
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Takei Y, Wong MKS, Ando M. Molecular mechanisms for intestinal HCO3− secretion and its regulation by guanylin in seawater-acclimated eels. J Exp Biol 2019; 222:jeb.203539. [DOI: 10.1242/jeb.203539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 06/03/2019] [Indexed: 01/25/2023]
Abstract
The intestine of marine teleosts secretes HCO3− into the lumen and precipitates Ca2+ and Mg2+ in the imbibed seawater as carbonates to decrease luminal fluid osmolality and facilitate water absorption. However, hormonal regulation of HCO3−secretion is largely unknown. Here, mucosally-added guanylin (GN) increased HCO3− secretion, measured by pH-stat, across isolated seawater-acclimated eel intestine bathed in saline at pH 7.4 (5% CO2). The effect of GN on HCO3− secretion was slower than that on the short-circuit current, and the time-course of the GN effect was similar to that of bumetanide. Mucosal bumetanide and serosal 4,4’-dinitrostilbene-2,2’-disulfonic acid (DNDS) inhibited the GN effect, suggesting an involvement of apical Na+-K+-2Cl− cotransporter (NKCC2) and basolateral Cl−/HCO3− exchanger (AE)/Na+-HCO3− cotransporter (NBC) in the GN effect. As mucosal DNDS failed to inhibit the GN effect, apical DNDS-sensitive AE may not be involved. To identify molecular species of transporters involved in the GN effect, we performed RNA-seq analyses followed by quantitative real-time PCR after transfer of eels to seawater. Among the genes upregulated after seawater transfer, AE genes, draa, b, and pat1a, c, on the apical membrane, and NBC genes, nbce1a, n1, n2a, and a AE gene, sat-1, on the basolateral membrane were candidates involved in HCO3− secretion. Judging from the slow effect of GN, we suggest that GN inhibits NKCC2b on the apical membrane and decreases cytosolic Cl− and Na+, which then activates apical DNDS-insensitive DRAs and basolateral DNDS-sensitive NBCs to enhance transcellular HCO3− flux across the intestinal epithelia of seawater-acclimated eels.
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Affiliation(s)
- Yoshio Takei
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, the University of Tokyo, Kashiwa, Chiba 277-8564, Japan
| | - Marty K. S. Wong
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, the University of Tokyo, Kashiwa, Chiba 277-8564, Japan
| | - Masaaki Ando
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, the University of Tokyo, Kashiwa, Chiba 277-8564, Japan
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24
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Whole-Genome Sequencing of 84 Japanese Eels Reveals Evidence against Panmixia and Support for Sympatric Speciation. Genes (Basel) 2018; 9:genes9100474. [PMID: 30274234 PMCID: PMC6210723 DOI: 10.3390/genes9100474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/17/2018] [Accepted: 09/21/2018] [Indexed: 12/30/2022] Open
Abstract
The Japanese eel (Anguilla japonica), European eel (Anguilla anguilla), and American eel (Anguilla rostrata) are migratory, catadromous, temperate zone fish sharing several common life cycle features. The population genetics of panmixia in these eel species has already been investigated. Our extensive population genetics analysis was based on 1400 Gb of whole-genome sequence (WGS) data from 84 eels. It demonstrated that a Japanese eel group from the Kuma River differed from other populations of the same species. Even after removing the potential adapted/selected single nucleotide polymorphism (SNP) data, and with very small differences (fixation index [Fst] = 0.01), we obtained results consistently indicating that panmixia does not occur in Japanese eels. The life cycle of the Japanese eel is well-established and the Kuma River is in the center of its habitat. Nevertheless, simple reproductive isolation is not the probable cause of non-panmixia in this species. We propose that the combination of spawning area subdivision, philopatry, and habitat preference/avoidance accounts for the non-panmixia in the Japanese eel population. We named this hypothesis the “reproductive isolation like subset mapping” (RISM) model. This finding may be indicative of the initial stages of sympatric speciation in these eels.
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25
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Nomura K, Fujiwara A, Iwasaki Y, Nishiki I, Matsuura A, Ozaki A, Sudo R, Tanaka H. Genetic parameters and quantitative trait loci analysis associated with body size and timing at metamorphosis into glass eels in captive-bred Japanese eels (Anguilla japonica). PLoS One 2018; 13:e0201784. [PMID: 30157280 PMCID: PMC6114518 DOI: 10.1371/journal.pone.0201784] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 07/23/2018] [Indexed: 01/31/2023] Open
Abstract
The Japanese eel (Anguilla japonica) is among the most important aquaculture fish species in Eastern Asia. The present study aimed to identify the genetic parameters underlying body size and the timing at metamorphosis from leptocephali to glass eels in captive-bred Japanese eels, with the intent to foster sustainable development. Larvae from a partly factorial cross (14 sires × 11 dams) were reared until the point of metamorphosis into glass eels. In these organisms, we observed moderate heritability and mild genetic correlations among traits related to body size (h2 = 0.16–0.33) and timing at metamorphosis (h2 = 0.36–0.41). In an F1 full-sib family, quantitative trait loci (QTL) mapping for these traits identified one significant (genome-wide P < 0.05) and five suggestive QTLs (chromosome-wide P < 0.05). These results suggest that in the Japanese eel, metamorphic traits exhibit a polygenic genetic structure comprising many QTLs with small effects. In addition, we updated the genetic linkage map for the Japanese eel and integrated it with our newly constructed de novo genome assembly. The information and tools generated from this study will contribute to the development of freshwater eel genetics and genomics.
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Affiliation(s)
- Kazuharu Nomura
- National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-ise, Mie, Japan
- * E-mail:
| | - Atushi Fujiwara
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Yuki Iwasaki
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Issei Nishiki
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Aiko Matsuura
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Akiyuki Ozaki
- National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-ise, Mie, Japan
| | - Ryusuke Sudo
- National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-ise, Mie, Japan
| | - Hideki Tanaka
- National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-ise, Mie, Japan
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26
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Cardoso JCR, Félix RC, Costa C, Palma PFS, Canário AVM, Power DM. Evolution of the glucagon-like system across fish. Gen Comp Endocrinol 2018; 264:113-130. [PMID: 29056448 DOI: 10.1016/j.ygcen.2017.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/04/2017] [Accepted: 10/10/2017] [Indexed: 12/25/2022]
Abstract
In fishes, including the jawless lampreys, the most ancient lineage of extant vertebrates, plasma glucose levels are highly variable and regulation is more relaxed than in mammals. The regulation of glucose and lipid in fishes in common with mammals involves members of the glucagon (GCG)-like family of gastrointestinal peptides. In mammals, four peptides GCG, glucagon-like peptide 1 and 2 (GLP1 and GLP2) and glucose-dependent insulinotropic peptide (GIP) that activate four specific receptors exist. However, in lamprey and other fishes the glucagon-like family evolved differently and they retained additional gene family members (glucagon-related peptide, gcrp and its receptor, gcrpr) that are absent from mammals. In the present study, we analysed the evolution of the glucagon-like system in fish and characterized gene expression of the family members in the European sea bass (Dicentrarchus labrax) a teleost fish. Phylogenetic analysis revealed that multiple receptors and peptides of the glucagon-like family emerged early during the vertebrate radiation and evolved via lineage specific events. Synteny analysis suggested that family member gene loss is likely to be the result of a single gene deletion event. Lamprey was the only fish where a putative glp1r persisted and the presence of the receptor gene in the genomes of the elephant shark and coelacanth remains unresolved. In the coelacanth and elephant shark, unique proglucagon genes were acquired which in the former only encoded Gcg and Glp2 and in the latter, shared a similar structure to the teleost proglucagon gene but possessed an extra exon coding for Glp-like peptide that was most similar to Glp2. The variable tissue distribution of the gene transcripts encoding the ligands and receptors of the glucagon-like system in an advanced teleost, the European sea bass, suggested that, as occurs in mammals, they have acquired distinct functions. Statistically significant (p < .05) down-regulation of teleost proglucagon a in sea bass with modified plasma glucose levels confirmed the link between these peptides and metabolism. The tissue distribution of members of the glucagon-like system in sea bass and human suggests that evolution of the brain-gut-peptide regulatory loop diverged between teleosts and mammals despite the overall conservation and similarity of glucagon-like family members.
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Affiliation(s)
- João C R Cardoso
- Comparative Endocrinology and Integrative Biology, Centre of Marine Sciences, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
| | - Rute C Félix
- Comparative Endocrinology and Integrative Biology, Centre of Marine Sciences, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
| | - Carina Costa
- Comparative Endocrinology and Integrative Biology, Centre of Marine Sciences, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Pedro F S Palma
- Comparative Endocrinology and Integrative Biology, Centre of Marine Sciences, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
| | - Adelino V M Canário
- Comparative Endocrinology and Integrative Biology, Centre of Marine Sciences, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
| | - Deborah M Power
- Comparative Endocrinology and Integrative Biology, Centre of Marine Sciences, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
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Matsubara K, Iwasaki Y, Nishiki I, Nomura K, Fujiwara A. Identification of genetic linkage group 1-linked sequences in Japanese eel (Anguilla japonica) by single chromosome sorting and sequencing. PLoS One 2018; 13:e0197040. [PMID: 29738551 PMCID: PMC5940218 DOI: 10.1371/journal.pone.0197040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 04/25/2018] [Indexed: 11/18/2022] Open
Abstract
Japanese eel (Anguilla japonica) constitutes one of the most important food fish in Japan; accordingly, genome sequencing and linkage mapping have been conducted for the purpose of artificial cultivation. In the next stage, integration of genomic sequences within linkage groups (LG) is required to construct higher-resolution genetic markers for quantitative trait loci mapping and selective breeding of beneficial traits in farming. In order to identify LG1-linked scaffolds from the draft genome assembly (323,776 scaffolds) reported previously, we attempted to isolate chromosomes corresponding to LG1 by flow sorting and subsequent analyses. Initially, single chromosomes were randomly collected by chromosome sorting and subjected to whole-genome amplification (WGA). A total of 60 WGA samples were screened by PCR with primers for a known LG1-linked scaffold, and five positive WGA samples were sequenced by next-generation sequencing (NGS). Following reference mapping analysis of the NGS reads, four of the five WGA samples were found to be enriched by LG1-linked sequences. These samples were cytogenetically assigned to chromosome 5 by fluorescence in situ hybridization. Using blastn searches with 82,081 contigs constructed from the NGS reads of the four WGA samples as queries, 2323 scaffolds were identified as putative LG1-linked scaffolds from the draft genome assembly. The total length of the putative LG1-linked scaffolds was 99.0 Mb, comparable to the estimated DNA amounts of chromosome 5 (91.1 Mb). These results suggest that the methodology developed herein is applicable to isolate specific chromosome DNAs and integrate unanchored scaffold sequences onto a particular LG and chromosome even in teleost fishes, in which isolation of specific chromosomes by flow sorting is generally difficult owing to similar morphologies, sizes, and GC-contents among chromosomes in the genome. The putative LG1-linked scaffolds of Japanese eel contain a total of 6833 short tandem repeats which will be available for higher-resolution linkage mapping.
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Affiliation(s)
- Kazumi Matsubara
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Yuki Iwasaki
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Issei Nishiki
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
| | - Kazuharu Nomura
- National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Minami-ise, Mie, Japan
| | - Atushi Fujiwara
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, Japan
- * E-mail:
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28
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Cao Q, Gu J, Wang D, Liang F, Zhang H, Li X, Yin S. Physiological mechanism of osmoregulatory adaptation in anguillid eels. FISH PHYSIOLOGY AND BIOCHEMISTRY 2018; 44:423-433. [PMID: 29344774 PMCID: PMC5862950 DOI: 10.1007/s10695-018-0464-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 01/03/2018] [Indexed: 06/07/2023]
Abstract
In recent years, the production of eel larvae has dramatic declines due to reductions in spawning stocks, overfishing, growth habitat destruction and access reductions, and pollution. Therefore, it is particularly important and urgent for artificial production of glass eels. However, the technique of artificial hatching and rearing larvae is still immature, which has long been regarded as an extremely difficult task. One of the huge gaps is artificial condition which is far from the natural condition to develop their capability of osmoregulation. Thus, understanding their osmoregulatory mechanisms will help to improve the breed and adapt to the changes in the environment. In this paper, we give a general review for a study progress of osmoregulatory mechanisms in eels from five aspects including tissues and organs, ion transporters, hormones, proteins, and high throughput sequencing methods.
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Affiliation(s)
- Quanquan Cao
- College of Life Sciences, Key Laboratory of Biodiversity and Biotechnology of Jiangsu Province, Nanjing Normal University, 1 Wenyuan Road, Nanjing, Jiangsu Province, 210023, China
| | - Jie Gu
- Institute of Life Science, Jiangsu University, Zhenjiang, Jiangsu, 212000, China
| | - Dan Wang
- College of Life Sciences, Key Laboratory of Biodiversity and Biotechnology of Jiangsu Province, Nanjing Normal University, 1 Wenyuan Road, Nanjing, Jiangsu Province, 210023, China
| | - Fenfei Liang
- College of Life Sciences, Key Laboratory of Biodiversity and Biotechnology of Jiangsu Province, Nanjing Normal University, 1 Wenyuan Road, Nanjing, Jiangsu Province, 210023, China
| | - Hongye Zhang
- College of Life Sciences, Key Laboratory of Biodiversity and Biotechnology of Jiangsu Province, Nanjing Normal University, 1 Wenyuan Road, Nanjing, Jiangsu Province, 210023, China
| | - Xinru Li
- College of Life Sciences, Key Laboratory of Biodiversity and Biotechnology of Jiangsu Province, Nanjing Normal University, 1 Wenyuan Road, Nanjing, Jiangsu Province, 210023, China
| | - Shaowu Yin
- College of Life Sciences, Key Laboratory of Biodiversity and Biotechnology of Jiangsu Province, Nanjing Normal University, 1 Wenyuan Road, Nanjing, Jiangsu Province, 210023, China.
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Noh ES, Kang HS, Kim EM, Noh JK, Park JY, Choi TJ, Kang JH. Rapid Differentiation of Seven Species of Anguilla Using PNA Clamping-based Asymmetric PCR with Fluorescence Melting Curve Analysis. BIOCHIP JOURNAL 2018. [DOI: 10.1007/s13206-017-2106-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Yada T, Mekuchi M, Ojima N. Molecular biology and functional genomics of immune-endocrine interactions in the Japanese eel, Anguilla japonica. Gen Comp Endocrinol 2018; 257:272-279. [PMID: 29108728 DOI: 10.1016/j.ygcen.2017.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 10/03/2017] [Accepted: 11/02/2017] [Indexed: 10/18/2022]
Abstract
Immune-endocrine interactions are an important pathogen resistance mechanism in fish. We review the immune-endocrine interactions in the Japanese eel, Anguilla japonica, with special reference to high throughput gene sequencing. These data may be relevant to the significant decrease in the eel harvest in recent years and will aid in the selection of appropriate disease-resistant strains for aquaculture. More than 1000 sequences that whose expression in elvers responded to air exposure were identified through comprehensive gene expression analysis using next-generation sequencing. These included transcription factors within the MAPK pathway. Significant changes in expression after air exposure were detected by quantitative polymerase chain reaction analysis in many genes related to disease resistance. These factors include innate immune system factors and cytokines that interact with the endocrine system during the stress response. Other applications of immune-endocrine interactions in eel culture are discussed.
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Affiliation(s)
- Takashi Yada
- Freshwater Fisheries Research Center, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Nikko, Japan.
| | - Miyuki Mekuchi
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Japan
| | - Nobuhiko Ojima
- Research Center for Bioinformatics and Biosciences, National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Japan
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Wong MKS, Tsukada T, Ogawa N, Pipil S, Ozaki H, Suzuki Y, Iwasaki W, Takei Y. A sodium binding system alleviates acute salt stress during seawater acclimation in eels. ZOOLOGICAL LETTERS 2017; 3:22. [PMID: 29255617 PMCID: PMC5727781 DOI: 10.1186/s40851-017-0081-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 10/11/2017] [Indexed: 05/28/2023]
Abstract
BACKGROUND Teleosts transiting from freshwater (FW) to seawater (SW) environments face an immediate osmotic stress from ion influxes and water loss, but some euryhaline species such as eels can maintain a stable plasma osmolality during early SW exposure. The time course changes in the gene expression, protein abundance, and localization of key ion transporters suggested that the reversal of the ion transport systems was gradual, and we investigate how eels utilize a Na-binding strategy to slow down the ion invasion and complement the transporter-mediated osmoregulation. RESULTS Using an electron probe micro-analyzer, we localized bound Na in various eel tissues in response to SW transfer, suggesting that the Na-binding molecules were produced to sequester excess ionic Na+ to negate its osmotic potential, thus preventing acute cellular dehydration. Mucus cells were acutely activated in digestive tract, gill, and skin after SW transfer, producing Na-binding molecule-containing mucus layers that fence off high osmolality of SW. Using gel filtration HPLC, some molecules at 18 kDa were found to bind Na in the luminal secretion of esophagus and intestine, and higher binding was associated with SW transfer. Transcriptome and protein interaction results indicated that downregulation of Notch and β-catenin pathways, and dynamic changes in TGFβ pathways in intestine were involved during early SW transition, supporting the observed histological changes on epithelial desquamation and increased mucus production. CONCLUSIONS The timing for the activation of the Na-binding mechanism to alleviate the adverse osmotic gradient was temporally complementary to the subsequent remodeling of branchial ionocytes and transporting epithelia of the digestive tract. The strategy to manipulate the osmotic potential of Na+ by specific binding molecules is similar to the osmotically inactive Na described in human skin and muscle. The Na-binding molecules provide a buffer to tolerate the salinity changes, which is advantageous to the estuary and migrating fishes. Our data pave the way to identify this unknown class of molecules and open a new area of vertebrate osmoregulation research.
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Affiliation(s)
- Marty Kwok Shing Wong
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa City, Japan
| | - Takehiro Tsukada
- Department of Biomolecular Science, Toho University, Funabashi City, Japan
| | - Nobuhiro Ogawa
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa City, Japan
| | - Supriya Pipil
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa City, Japan
| | - Haruka Ozaki
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa City, Japan
- Bioinformatics Research Unit, Advanced Center for Computing and Communication, RIKEN, Wako City, Japan
| | - Yutaka Suzuki
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa City, Japan
| | - Wataru Iwasaki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa City, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa City, Japan
| | - Yoshio Takei
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa City, Japan
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Single nucleotide polymorphism markers for assessing potential maternal population structure in European eel (Anguilla anguilla). CONSERV GENET RESOUR 2017. [DOI: 10.1007/s12686-017-0917-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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33
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Kondo M, Yamamoto T, Takahashi S, Taira M. Comprehensive analyses ofhoxgene expression inXenopus laevisembryos and adult tissues. Dev Growth Differ 2017; 59:526-539. [DOI: 10.1111/dgd.12382] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 05/29/2017] [Indexed: 01/04/2023]
Affiliation(s)
- Mariko Kondo
- Misaki Marine Biological Station; Graduate School of Science and Center for Marine Biology; The University of Tokyo; 1024 Koajiro Misaki Miura Kanagawa 238-0225 Japan
| | - Takayoshi Yamamoto
- Department of Biological Sciences; Graduate School of Science; The University of Tokyo; 7-3-1 Hongo Bunkyo-ku Tokyo 113-0033 Japan
| | - Shuji Takahashi
- Institute for Amphibian Biology; Graduate School of Science; Hiroshima University; 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima 739-8526 Japan
| | - Masanori Taira
- Department of Biological Sciences; Graduate School of Science; The University of Tokyo; 7-3-1 Hongo Bunkyo-ku Tokyo 113-0033 Japan
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Jansen HJ, Liem M, Jong-Raadsen SA, Dufour S, Weltzien FA, Swinkels W, Koelewijn A, Palstra AP, Pelster B, Spaink HP, Thillart GEVD, Dirks RP, Henkel CV. Rapid de novo assembly of the European eel genome from nanopore sequencing reads. Sci Rep 2017; 7:7213. [PMID: 28775309 PMCID: PMC5543108 DOI: 10.1038/s41598-017-07650-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 06/28/2017] [Indexed: 02/07/2023] Open
Abstract
We have sequenced the genome of the endangered European eel using the MinION by Oxford Nanopore, and assembled these data using a novel algorithm specifically designed for large eukaryotic genomes. For this 860 Mbp genome, the entire computational process takes two days on a single CPU. The resulting genome assembly significantly improves on a previous draft based on short reads only, both in terms of contiguity (N50 1.2 Mbp) and structural quality. This combination of affordable nanopore sequencing and light weight assembly promises to make high-quality genomic resources accessible for many non-model plants and animals.
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Affiliation(s)
| | - Michael Liem
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | | | - Sylvie Dufour
- Muséum National d'Histoire Naturelle, Sorbonne Universités, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, UCN, UA, Paris, France
| | - Finn-Arne Weltzien
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Department of Basic Science and Aquatic Medicine, Oslo, Norway
| | | | | | - Arjan P Palstra
- Animal Breeding and Genomics Centre, Wageningen Livestock Research, Wageningen University & Research, Wageningen, The Netherlands
| | - Bernd Pelster
- Institute of Zoology and Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Herman P Spaink
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | | | | | - Christiaan V Henkel
- Institute of Biology, Leiden University, Leiden, The Netherlands.
- University of Applied Sciences Leiden, Leiden, The Netherlands.
- Generade Centre of Expertise in Genomics, Leiden, The Netherlands.
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35
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Lee SC, Hsiao CD, Wang YS, Lou SW. Transcriptome response of previtellogenic ovary in Anguilla japonica after artificial hormone injection. Mar Genomics 2017; 35:31-34. [PMID: 28478932 DOI: 10.1016/j.margen.2017.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 04/25/2017] [Accepted: 04/27/2017] [Indexed: 11/19/2022]
Abstract
In this study we investigate the intra-ovarian pathways underlying early follicle development in Japanese eels, Anguilla japonica. We conducted high-throughput transcriptome analyses in the initial development of the ovary via the next-generation sequencing (NGS). Japanese eels were treated with three weekly salmon pituitary homogenate (SPH) injections. Using RNA-seq, we obtained 29,117,237 and 41,867,557 reads from the control and the SPH-injected groups, respectively. Combining these RNA-seq datasets, we acquired a total of 101,711 unigenes (N50=1,517bp) after performing de novo assembly. After differentially expressed gene (DEG) analysis, 4,211 and 7,059 annotated genes showed upregulation and downregulation respectively in SPH-injected ovarian tissues. Furthermore, functions of annotated genes were classified by GO and KEGG analyses. The PTEN/PI3K-Akt pathway, Tsc/mTOR signaling, oocyte meiosis and reproduction functions were found in data of differentially expressed genes.
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Affiliation(s)
- Shang-Chien Lee
- Institute of Fisheries Science, College of life science, National Taiwan University, Taipei 10617, Taiwan
| | - Chung-Der Hsiao
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li district, Taoyuan, city 32023, Taiwan
| | - Yung-Song Wang
- Institute of Fisheries Science, College of life science, National Taiwan University, Taipei 10617, Taiwan.
| | - Show-Wan Lou
- Institute of Fisheries Science, College of life science, National Taiwan University, Taipei 10617, Taiwan.
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36
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Nuclear and membrane progestin receptors in the European eel: Characterization and expression in vivo through spermatogenesis. Comp Biochem Physiol A Mol Integr Physiol 2017; 207:79-92. [DOI: 10.1016/j.cbpa.2017.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/02/2017] [Accepted: 02/05/2017] [Indexed: 01/04/2023]
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37
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Evolution of Shh endoderm enhancers during morphological transition from ventral lungs to dorsal gas bladder. Nat Commun 2017; 8:14300. [PMID: 28155855 PMCID: PMC5296767 DOI: 10.1038/ncomms14300] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/16/2016] [Indexed: 11/13/2022] Open
Abstract
Shh signalling plays a crucial role for endoderm development. A Shh endoderm enhancer, MACS1, is well conserved across terrestrial animals with lungs. Here, we first show that eliminating mouse MACS1 causes severe defects in laryngeal development, indicating that MACS1-directed Shh signalling is indispensable for respiratory organogenesis. Extensive phylogenetic analyses revealed that MACS1 emerged prior to the divergence of cartilaginous and bony fishes, and even euteleost fishes have a MACS1 orthologue. Meanwhile, ray-finned fishes evolved a novel conserved non-coding sequence in the neighbouring region. Transgenic assays showed that MACS1 drives reporter expression ventrally in laryngeal epithelium. This activity has been lost in the euteleost lineage, and instead, the conserved non-coding sequence of euteleosts acquired an enhancer activity to elicit dorsal epithelial expression in the posterior pharynx and oesophagus. These results implicate that evolution of these two enhancers is relevant to the morphological transition from ventral lungs to dorsal gas bladder. Endoderm enhancer MACS1 of Sonic Hedgehog is conserved in animals with lungs. Here, the authors show that mouse without MACS1 has defective laryngeal development, and use phylogenetic analyses to show association of evolutionary lung-gas bladder transition with change of the enhancer.
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38
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Morini M, Peñaranda DS, Vílchez MC, Tveiten H, Lafont AG, Dufour S, Pérez L, Asturiano JF. The expression of nuclear and membrane estrogen receptors in the European eel throughout spermatogenesis. Comp Biochem Physiol A Mol Integr Physiol 2017; 203:91-99. [DOI: 10.1016/j.cbpa.2016.08.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 08/03/2016] [Accepted: 08/24/2016] [Indexed: 02/02/2023]
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39
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Takei Y, Wong MKS, Pipil S, Ozaki H, Suzuki Y, Iwasaki W, Kusakabe M. Molecular mechanisms underlying active desalination and low water permeability in the esophagus of eels acclimated to seawater. Am J Physiol Regul Integr Comp Physiol 2016; 312:R231-R244. [PMID: 28003213 DOI: 10.1152/ajpregu.00465.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/19/2016] [Accepted: 12/21/2016] [Indexed: 11/22/2022]
Abstract
Marine teleosts can absorb imbibed seawater (SW) to maintain water balance, with esophageal desalination playing an essential role. NaCl absorption from luminal SW was enhanced 10-fold in the esophagus of SW-acclimated eels, and removal of Na+ or Cl- from luminal SW abolished the facilitated absorption, indicating coupled transport. Mucosal/serosal application of various blockers for Na+/Cl- transporters profoundly decreased the absorption. Among the transporter genes expressed in eel esophagus detected by RNA-seq, dimethyl amiloride-sensitive Na+/H+ exchanger (NHE3) and 4,4'-diisothiocyano-2,2'-disulfonic acid-sensitive Cl-/[Formula: see text] exchanger (AE) coupled by the scaffolding protein on the apical membrane of epithelial cells, and ouabain-sensitive Na+-K+-ATPases (NKA1α1c and NKA3α) and diphenylamine-2-carboxylic acid-sensitive Cl- channel (CLCN2) on the basolateral membrane, may be responsible for enhanced transcellular NaCl transport because of their profound upregulation after SW acclimation. Upregulated carbonic anhydrase 2a (CA2a) supplies H+ and [Formula: see text] for activation of the coupled NHE and AE. Apical hydrochlorothiazide-sensitive Na+-Cl- cotransporters and basolateral Na+-[Formula: see text] cotransporter (NBCe1) and AE1 are other possible candidates. Concerning the low water permeability that is typically seen in marine teleost esophagus, downregulated aquaporin genes (aqp1a and aqp3) and upregulated claudin gene (cldn15a) are candidates for transcellular/paracellular route. In situ hybridization showed that these upregulated transporters and tight-junction protein genes were expressed in the absorptive columnar epithelial cells of eel esophagus. These results allow us to provide a full picture of the molecular mechanism of active desalination and low water permeability that are characteristic to marine teleost esophagus and gain deeper insights into the role of gastrointestinal tracts in SW acclimation.
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Affiliation(s)
- Yoshio Takei
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba, Japan;
| | - Marty K-S Wong
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba, Japan
| | - Supriya Pipil
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba, Japan
| | - Haruka Ozaki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan.,Bioinformatics Research Unit, Advanced Center for Computing and Communication, RIKEN, Wako, Saitama, Japan; and
| | - Yutaka Suzuki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan
| | - Wataru Iwasaki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan.,Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Makoto Kusakabe
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba, Japan
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40
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Pavey SA, Laporte M, Normandeau E, Gaudin J, Letourneau L, Boisvert S, Corbeil J, Audet C, Bernatchez L. Draft genome of the American Eel (Anguilla rostrata). Mol Ecol Resour 2016; 17:806-811. [PMID: 27754597 DOI: 10.1111/1755-0998.12608] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 10/12/2016] [Accepted: 10/13/2016] [Indexed: 11/28/2022]
Abstract
Freshwater eels (Anguilla sp.) have large economic, cultural, ecological and aesthetic importance worldwide, but they suffered more than 90% decline in global stocks over the past few decades. Proper genetic resources, such as sequenced, assembled and annotated genomes, are essential to help plan sustainable recoveries by identifying physiological, biochemical and genetic mechanisms that caused the declines or that may lead to recoveries. Here, we present the first sequenced genome of the American eel. This genome contained 305 043 contigs (N50 = 7397) and 79 209 scaffolds (N50 = 86 641) for a total size of 1.41 Gb, which is in the middle of the range of previous estimations for this species. In addition, protein-coding regions, including introns and flanking regions, are very well represented in the genome, as 95.2% of the 458 core eukaryotic genes and 98.8% of the 248 ultra-conserved subset were represented in the assembly and a total of 26 564 genes were annotated for future functional genomics studies. We performed a candidate gene analysis to compare three genes among all three freshwater eel species and, congruent with the phylogenetic relationships, Japanese eel (A. japanica) exhibited the most divergence. Overall, the sequenced genome presented in this study is a crucial addition to the presently available genetic tools to help guide future conservation efforts of freshwater eels.
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Affiliation(s)
- Scott A Pavey
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Pavillon Charles-Eugène-Marchand, Québec, QC, G1V 0A6, Canada.,Department of Biological Sciences and Canadian Rivers Institute, University of New Brunswick, Saint-John, NB, E2L 4L5, Canada
| | - Martin Laporte
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Pavillon Charles-Eugène-Marchand, Québec, QC, G1V 0A6, Canada
| | - Eric Normandeau
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Pavillon Charles-Eugène-Marchand, Québec, QC, G1V 0A6, Canada
| | - Jérémy Gaudin
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Pavillon Charles-Eugène-Marchand, Québec, QC, G1V 0A6, Canada
| | - Louis Letourneau
- McGill University and Génome Québec Innovation Centre, Montréal, QC, H3A0G1, Canada
| | - Sébastien Boisvert
- Faculty of Medicine, CHUL Research Center, Université Laval, Québec, QC, G1V4G2, Canada
| | - Jacques Corbeil
- Faculty of Medicine, CHUL Research Center, Université Laval, Québec, QC, G1V4G2, Canada
| | - Céline Audet
- Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, Rimouski, Québec, G5L 3A1, Canada
| | - Louis Bernatchez
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Pavillon Charles-Eugène-Marchand, Québec, QC, G1V 0A6, Canada
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Lafont AG, Rousseau K, Tomkiewicz J, Dufour S. Three nuclear and two membrane estrogen receptors in basal teleosts, Anguilla sp.: Identification, evolutionary history and differential expression regulation. Gen Comp Endocrinol 2016; 235:177-191. [PMID: 26654744 DOI: 10.1016/j.ygcen.2015.11.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 11/26/2015] [Accepted: 11/29/2015] [Indexed: 12/17/2022]
Abstract
Estrogens interact with classical intracellular nuclear receptors (ESR), and with G-coupled membrane receptors (GPER). In the eel, we identified three nuclear (ESR1, ESR2a, ESR2b) and two membrane (GPERa, GPERb) estrogen receptors. Duplicated ESR2 and GPER were also retrieved in most extant teleosts. Phylogeny and synteny analyses suggest that they result from teleost whole genome duplication (3R). In contrast to conserved 3R-duplicated ESR2 and GPER, one of 3R-duplicated ESR1 has been lost shortly after teleost emergence. Quantitative PCRs revealed that the five receptors are all widely expressed in the eel, but with differential patterns of tissue expression and regulation. ESR1 only is consistently up-regulated in vivo in female eel BPG-liver axis during induced sexual maturation, and also up-regulated in vitro by estradiol in eel hepatocyte primary cultures. This first comparative study of the five teleost estradiol receptors provides bases for future investigations on differential roles that may have contributed to the conservation of multiple estrogen receptors.
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Affiliation(s)
- Anne-Gaëlle Lafont
- Muséum National d'Histoire Naturelle, Sorbonne Universités, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS 7208, IRD207, UPMC, UCN, Paris, France.
| | - Karine Rousseau
- Muséum National d'Histoire Naturelle, Sorbonne Universités, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS 7208, IRD207, UPMC, UCN, Paris, France
| | - Jonna Tomkiewicz
- Technical University of Denmark, National Institute of Aquatic Resources, Charlottenlund, Denmark
| | - Sylvie Dufour
- Muséum National d'Histoire Naturelle, Sorbonne Universités, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS 7208, IRD207, UPMC, UCN, Paris, France.
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42
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Metzger DC, Hemmer-Hansen J, Schulte PM. Conserved structure and expression of hsp70 paralogs in teleost fishes. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2016; 18:10-20. [DOI: 10.1016/j.cbd.2016.01.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/21/2016] [Accepted: 01/24/2016] [Indexed: 12/14/2022]
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43
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Murgarella M, Puiu D, Novoa B, Figueras A, Posada D, Canchaya C. A First Insight into the Genome of the Filter-Feeder Mussel Mytilus galloprovincialis. PLoS One 2016; 11:e0151561. [PMID: 26977809 PMCID: PMC4792442 DOI: 10.1371/journal.pone.0151561] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 03/01/2016] [Indexed: 02/06/2023] Open
Abstract
Mussels belong to the phylum Mollusca, one of the largest and most diverse taxa in the animal kingdom. Despite their importance in aquaculture and in biology in general, genomic resources from mussels are still scarce. To broaden and increase the genomic knowledge in this family, we carried out a whole-genome sequencing study of the cosmopolitan Mediterranean mussel (Mytilus galloprovincialis). We sequenced its genome (32X depth of coverage) on the Illumina platform using three pair-end libraries with different insert sizes. The large number of contigs obtained pointed out a highly complex genome of 1.6 Gb where repeated elements seem to be widespread (~30% of the genome), a feature that is also shared with other marine molluscs. Notwithstanding the limitations of our genome sequencing, we were able to reconstruct two mitochondrial genomes and predict 10,891 putative genes. A comparative analysis with other molluscs revealed a gene enrichment of gene ontology categories related to multixenobiotic resistance, glutamate biosynthetic process, and the maintenance of ciliary structures.
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Affiliation(s)
- Maria Murgarella
- Department of Biochemistry, Genetics and Immunology and Unidad Asociada CSIC, University of Vigo, Vigo, Spain
| | - Daniela Puiu
- Center for Computational Biology. McKusick-Nathans, Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Beatriz Novoa
- Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas, Vigo, Spain
| | - Antonio Figueras
- Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas, Vigo, Spain
| | - David Posada
- Department of Biochemistry, Genetics and Immunology and Unidad Asociada CSIC, University of Vigo, Vigo, Spain
| | - Carlos Canchaya
- Department of Biochemistry, Genetics and Immunology and Unidad Asociada CSIC, University of Vigo, Vigo, Spain
- * E-mail:
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Liu YC, Hsu SD, Chou CH, Huang WY, Chen YH, Liu CY, Lyu GJ, Huang SZ, Aganezov S, Alekseyev MA, Hsiao CD, Huang HD. Transcriptome sequencing based annotation and homologous evidence based scaffolding of Anguilla japonica draft genome. BMC Genomics 2016; 17 Suppl 1:13. [PMID: 26818233 PMCID: PMC4895481 DOI: 10.1186/s12864-015-2306-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Background Anguilla japonica (Japanese eel) is currently one of the most important research subjects in eastern Asia aquaculture. Enigmatic life cycle of the organism makes study of artificial reproduction extremely limited. Henceforth genomic and transcriptomic resources of eels are urgently needed to help solving the problems surrounding this organism across multiple fields. We hereby provide a reconstructed transcriptome from deep sequencing of juvenile (glass eels) whole body samples. The provided expressed sequence tags were used to annotate the currently available draft genome sequence. Homologous information derived from the annotation result was applied to improve the group of scaffolds into available linkage groups. Results With the transcriptome sequence data combined with publicly available expressed sequence tags evidences, 18,121 genes were structurally and functionally annotated on the draft genome. Among them, 3,921 genes were located in the 19 linkage groups. 137 scaffolds covering 13 million bases were grouped into the linkage groups in additional to the original partial linkage groups, increasing the linkage group coverage from 13 to 14 %. Conclusions This annotation provide information of the coding regions of the genes supported by transcriptome based evidence. The derived homologous evidences pave the way for phylogenetic analysis of important genetic traits and the improvement of the genome assembly. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2306-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yu-Chen Liu
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC
| | - Sheng-Da Hsu
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC
| | - Chih-Hung Chou
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC
| | - Wei-Yun Huang
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC
| | - Yu-Hung Chen
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC
| | - Chia-Yu Liu
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC
| | - Guan-Jay Lyu
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC
| | - Shao-Zhen Huang
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC
| | - Sergey Aganezov
- Computational Biology Institute & Department of Mathematics, George Washington University, Washington, DC, USA.,Department of Higher Mathematics, ITMO University, St. Petersburg, Russia
| | - Max A Alekseyev
- Computational Biology Institute & Department of Mathematics, George Washington University, Washington, DC, USA
| | - Chung-Der Hsiao
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li, Taiwan, ROC.
| | - Hsien-Da Huang
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC. .,Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu, 300, Taiwan, ROC. .,Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan.
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Wong MKS, Pipil S, Ozaki H, Suzuki Y, Iwasaki W, Takei Y. Flexible selection of diversified Na(+)/K(+)-ATPase α-subunit isoforms for osmoregulation in teleosts. ZOOLOGICAL LETTERS 2016; 2:15. [PMID: 27489726 PMCID: PMC4971688 DOI: 10.1186/s40851-016-0050-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 07/18/2016] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND METHODS Multiple Na+/K+-ATPase (NKA) α-subunit isoforms express differentially in response to salinity transfer in teleosts but we observed that the isoform nomenclature is inconsistent with the phylogenetic relationship of NKA α-genes. We cloned the catalytic NKA α-subunit isoforms in eels and medaka, analyzed the time course of their expressions in osmoregulatory tissues after transfer from freshwater (FW) to seawater (SW), and performed phylogenetic analyses to deduce an evolutionary scenario that illustrates how various duplication events have led to the current genomic arrangement of NKA α-genes in teleosts. RESULTS AND DISCUSSION Five and six α-subunits were cloned in eels and medaka respectively. In eels, the commonly-reported α1a and α1b isoforms were absent while the α1c isoform was diversified instead (α1c-1, α1c-2, α1c-3, α2, and α3 in eels). Phylogenetic estimation indicated that the α1a and α1b isoforms from salmon, tilapia, and medaka were generated by independent duplication events and thus they are paralogous isoforms. Re-examination of expression changes of known isoforms after salinity challenge revealed that the isoforms selected as predominant SW-types varied among teleost lineages. Diversification of α1 isoforms occurred by various types of gene duplication, or by alternative transcription among tandem genes to form chimeric transcripts, but there is no trend for more α1 copies in euryhaline species. Our data suggest that the isoform switching between FW (α1a predominates) and SW (α1b predominates) that occurs in salmonids is not universal in teleosts. Instead, in eels, α1c-1 was the major α-subunit upregulated gill, intestine, and kidney in SW. Localization of both NKA mRNA and protein showed consistent upregulation in gill and intestine in SW eels, but not in renal distal and collecting tubules, where low transcript expression levels were accompanied by high protein levels, suggesting a tissue-specific translational regulation that determines and fine-tunes the NKA expression. In medaka, α1b was upregulated in SW in anterior intestine while most other α-subunit isoforms were less responsive to salinity changes. CONCLUSION By integrating gene expression and phylogenetic results, we propose that the major NKA α-subunits for SW acclimation were not ancestrally selected, but rather were flexibly determined in lineage-specific fashion in teleosts.
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Affiliation(s)
- Marty Kwok-Shing Wong
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba Japan
| | - Supriya Pipil
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba Japan
| | - Haruka Ozaki
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
- Bioinformatics Research Unit, Advanced Center for Computing and Communication, RIKEN, Wako, Saitama Japan
| | - Yutaka Suzuki
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
| | - Wataru Iwasaki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
| | - Yoshio Takei
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba Japan
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Lai KP, Li JW, Gu J, Chan TF, Tse WKF, Wong CKC. Transcriptomic analysis reveals specific osmoregulatory adaptive responses in gill mitochondria-rich cells and pavement cells of the Japanese eel. BMC Genomics 2015; 16:1072. [PMID: 26678671 PMCID: PMC4683740 DOI: 10.1186/s12864-015-2271-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 12/03/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Homeostasis of ions and water is important for the maintenance of cellular functions. The regulation of the homeostasis is particularly important in euryhaline fish that migrate between freshwater (FW) and seawater (SW) environments. The fish gill, the major tissue that forms an interface separating the extracellular fluids and external water environment, has an effective transport system to maintain and regulate a constant body osmolality. In fish gills, the two major epithelial cells, pavement cells (PVCs) and mitochondria-rich cells (MRCs), are known to play key and complementary roles in ion transport at the interface. Discovering the robust mechanisms underlying the two cell types' response to osmotic stress would benefit our understanding of the fundamental mechanism allowing PVCs and MRCs to handle osmotic stress. Owing to the limited genomic data available on estuarine species, existing knowledge in this area is slim. In this study, transcriptome analyses were conducted using PVCs and MRCs isolated from Japanese eels adapted to FW or SW environments to provide a genome-wide molecular study to unravel the fundamental processes at work. RESULTS The study identified more than 12,000 transcripts in the gill cells. Interestingly, remarkable differential expressed genes (DEGs) were identified in PVCs (970 transcripts) instead of MRCs (400 transcripts) in gills of fish adapted to FW or SW. Since PVCs cover more than 90 % of the gill epithelial surface, the greater change in gene expression patterns in PVCs in response to external osmolality is anticipated. In the integrity pathway analysis, 19 common biological functions were identified in PVCs and MRCs. In the enriched signaling pathways analysis, most pathways differed between PVCs and MRCs; 14 enriched pathways were identified in PVCs and 12 in MRCs. The results suggest that the osmoregulatory responses in PVCs and MRCs are cell-type specific, which supports the complementary functions of the cells in osmoregulation. CONCLUSIONS This is the first study to provide transcriptomic analysis of PVCs and MRCs in gills of eels adapted to FW or SW environments. It describes the cell-type specific transcriptomic network in different tonicity. The findings consolidate the known osmoregulatory pathways and provide molecular insight in osmoregulation. The presented data will be useful for researchers to select their targets for further studies.
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Affiliation(s)
- Keng Po Lai
- School of Biological Sciences, Kadoorie Biological Sciences Building, The University of Hong Kong, Pokfulam Road, Pok Fu Lam, Hong Kong
| | - Jing-Woei Li
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong.,Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Je Gu
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong
| | - Ting-Fung Chan
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - William Ka Fai Tse
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong.
| | - Chris Kong Chu Wong
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong. .,Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Pok Fu Lam, Hong Kong.
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Abstract
Recent improvements in next-generation sequencing technology have made it possible to do whole genome sequencing, on even non-model eukaryote species with no available reference genomes. However, de novo assembly of diploid genomes is still a big challenge because of allelic variation. The aim of this study was to determine the feasibility of utilizing the genome of haploid fish larvae for de novo assembly of whole-genome sequences. We compared the efficiency of assembly using the haploid genome of yellowtail (Seriola quinqueradiata) with that using the diploid genome obtained from the dam. De novo assembly from the haploid and the diploid sequence reads (100 million reads per each datasets) generated by the Ion Proton sequencer (200 bp) was done under two different assembly algorithms, namely overlap-layout-consensus (OLC) and de Bruijn graph (DBG). This revealed that the assembly of the haploid genome significantly reduced (approximately 22% for OLC, 9% for DBG) the total number of contigs (with longer average and N50 contig lengths) when compared to the diploid genome assembly. The haploid assembly also improved the quality of the scaffolds by reducing the number of regions with unassigned nucleotides (Ns) (total length of Ns; 45,331,916 bp for haploids and 67,724,360 bp for diploids) in OLC-based assemblies. It appears clear that the haploid genome assembly is better because the allelic variation in the diploid genome disrupts the extension of contigs during the assembly process. Our results indicate that utilizing the genome of haploid larvae leads to a significant improvement in the de novo assembly process, thus providing a novel strategy for the construction of reference genomes from non-model diploid organisms such as fish.
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Morini M, Peñaranda DS, Vílchez MC, Gallego V, Nourizadeh-Lillabadi R, Asturiano JF, Weltzien FA, Pérez L. Transcript levels of the soluble sperm factor protein phospholipase C zeta 1 (PLCζ1) increase through induced spermatogenesis in European eel. Comp Biochem Physiol A Mol Integr Physiol 2015; 187:168-76. [DOI: 10.1016/j.cbpa.2015.05.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/22/2015] [Accepted: 05/31/2015] [Indexed: 11/15/2022]
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Maugars G, Dufour S. Demonstration of the Coexistence of Duplicated LH Receptors in Teleosts, and Their Origin in Ancestral Actinopterygians. PLoS One 2015; 10:e0135184. [PMID: 26271038 PMCID: PMC4536197 DOI: 10.1371/journal.pone.0135184] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/18/2015] [Indexed: 11/18/2022] Open
Abstract
Pituitary gonadotropins, FSH and LH, control gonad activity in vertebrates, via binding to their respective receptors, FSHR and LHR, members of GPCR superfamily. Until recently, it was accepted that gnathostomes possess a single FSHR and a single LHR, encoded by fshr and lhcgr genes. We reinvestigated this question, focusing on vertebrate species of key-phylogenetical positions. Genome analyses supported the presence of a single fshr and a single lhcgr in chondrichthyans, and in sarcopterygians including mammals, birds, amphibians and coelacanth. In contrast, we identified a single fshr but two lhgcr in basal teleosts, the eels. We further showed the coexistence of duplicated lhgcr in other actinopterygians, including a non-teleost, the gar, and other teleosts, e.g. Mexican tetra, platyfish, or tilapia. Phylogeny and synteny analyses supported the existence in actinopterygians of two lhgcr paralogs (lhgcr1/ lhgcr2), which do not result from the teleost-specific whole-genome duplication (3R), but likely from a local gene duplication that occurred early in the actinopterygian lineage. Due to gene losses, there was no impact of 3R on the number of gonadotropin receptors in extant teleosts. Additional gene losses during teleost radiation, led to a single lhgcr (lhgcr1 or lhgcr2) in some species, e.g. medaka and zebrafish. Sequence comparison highlighted divergences in the extracellular and intracellular domains of the duplicated lhgcr, suggesting differential properties such as ligand binding and activation mechanisms. Comparison of tissue distribution in the European eel, revealed that fshr and both lhgcr transcripts are expressed in the ovary and testis, but are differentially expressed in non-gonadal tissues such as brain or eye. Differences in structure-activity relationships and tissue expression may have contributed as selective drives in the conservation of the duplicated lhgcr. This study revises the evolutionary scenario and nomenclature of gonadotropin receptors, and opens new research avenues on the roles of duplicated LHR in actinopterygians.
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Affiliation(s)
- Gersende Maugars
- Muséum National d'Histoire Naturelle, Sorbonne Universités, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS 7208-IRD 207-UPMC-UCBN, Paris, France
| | - Sylvie Dufour
- Muséum National d'Histoire Naturelle, Sorbonne Universités, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS 7208-IRD 207-UPMC-UCBN, Paris, France
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Callol A, Reyes-López FE, Roig FJ, Goetz G, Goetz FW, Amaro C, MacKenzie SA. An Enriched European Eel Transcriptome Sheds Light upon Host-Pathogen Interactions with Vibrio vulnificus. PLoS One 2015. [PMID: 26207370 PMCID: PMC4514713 DOI: 10.1371/journal.pone.0133328] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Infectious diseases are one of the principal bottlenecks for the European eel recovery. The aim of this study was to develop a new molecular tool to be used in host-pathogen interaction experiments in the eel. To this end, we first stimulated adult eels with different pathogen-associated molecular patterns (PAMPs), extracted RNA from the immune-related tissues and sequenced the transcriptome. We obtained more than 2x106 reads that were assembled and annotated into 45,067 new descriptions with a notable representation of novel transcripts related with pathogen recognition, signal transduction and the immune response. Then, we designed a DNA-microarray that was used to analyze the early immune response against Vibrio vulnificus, a septicemic pathogen that uses the gills as the portal of entry into the blood, as well as the role of the main toxin of this species (RtxA13) on this early interaction. The gill transcriptomic profiles obtained after bath infecting eels with the wild type strain or with a mutant deficient in rtxA13 were analyzed and compared. Results demonstrate that eels react rapidly and locally against the pathogen and that this immune-response is rtxA13-dependent as transcripts related with cell destruction were highly up-regulated only in the gills from eels infected with the wild-type strain. Furthermore, significant differences in the immune response against the wild type and the mutant strain also suggest that host survival after V. vulnificus infection could depend on an efficient local phagocytic activity. Finally, we also found evidence of the presence of an interbranchial lymphoid tissue in European eel gills although further experiments will be necessary to identify such tissue.
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Affiliation(s)
- Agnès Callol
- Departament de Microbiologia i Ecologia, Universitat de Valencia, Burjassot, Spain
- Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Felipe E. Reyes-López
- Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Department de Biologia cel·lular, Fisiologia Animal i Immunologia, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Francisco J. Roig
- Departament de Microbiologia i Ecologia, Universitat de Valencia, Burjassot, Spain
| | - Giles Goetz
- Northwest Fisheries Science Center, Seattle, United States of America
| | | | - Carmen Amaro
- Departament de Microbiologia i Ecologia, Universitat de Valencia, Burjassot, Spain
| | - Simon A. MacKenzie
- Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Institute of Aquaculture, University of Stirling, Stirling, United Kingdom
- * E-mail:
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