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Onishi Y, Yamanaka T, Koba K. Major contribution of sulfide-derived sulfur to the benthic food web in a large freshwater lake. Geobiology 2023; 21:671-685. [PMID: 37434444 DOI: 10.1111/gbi.12569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 06/19/2023] [Accepted: 06/29/2023] [Indexed: 07/13/2023]
Abstract
In freshwater systems, contributions of chemosynthetic products by sulfur-oxidizing bacteria in sediments as nutritional resources in benthic food webs remain unclear, even though chemosynthetic products might be an important nutritional resource for benthic food webs in deep-sea hydrothermal vents and shallow marine systems. To study geochemical aspects of this trophic pathway, we sampled sediment cores and benthic animals at two sites (90 and 50 m water depths) in the largest freshwater (mesotrophic) lake in Japan: Lake Biwa. Stable carbon, nitrogen, and sulfur isotopes of the sediments and animals were measured to elucidate the sulfur nutritional resources for the benthic food web precisely by calculating the contributions of the incorporation of sulfide-derived sulfur to the biomass and of the biogeochemical sulfur cycle supporting the sulfur nutritional resource. The recovered sediment cores showed increases in 34 S-depleted sulfide at 5 cm sediment depth and showed low sulfide concentration with high δ34 S in deeper layers, suggesting an association of microbial activities with sulfate reduction and sulfide oxidation in the sediments. The sulfur-oxidizing bacteria may contribute to benthic animal biomass. Calculations based on the biomass, sulfur content, and contribution to sulfide-derived sulfur of each animal comprising the benthic food web revealed that 58%-67% of the total biomass sulfur in the benthic food web of Lake Biwa is occupied by sulfide-derived sulfur. Such a large contribution implies that the chemosynthetic products of sulfur-oxidizing bacteria are important nutritional resources supporting benthic food webs in the lake ecosystems, at least in terms of sulfur. The results present a new trophic pathway for sulfur that has been overlooked in lake ecosystems with low-sulfate concentrations.
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Affiliation(s)
- Yuji Onishi
- Center for Ecological Research, Kyoto University, Otsu, Shiga, Japan
| | - Toshiro Yamanaka
- School of Marine Resources and Environment, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Keisuke Koba
- Center for Ecological Research, Kyoto University, Otsu, Shiga, Japan
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2
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Takemoto K, Murakami M, Tabuchi M, Ohta T. Spectroscopic studies for identifying the chemical states of the periostracum of the Corbicula species in Lake Biwa. J Struct Biol 2023; 215:107944. [PMID: 36841078 DOI: 10.1016/j.jsb.2023.107944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 02/04/2023] [Accepted: 02/13/2023] [Indexed: 02/27/2023]
Abstract
Corbicula clam shells consist of thin periostracum and calcareous layers made of calcium carbonate (CaCO3). Depending on habitat conditions, the shell exhibits various colorations, such as yellow, brown, and black. The chemical state of the periostracum of the Corbicula species in Lake Biwa was studied by X-ray absorption fine structure (XAFS) and Raman scattering spectroscopies. Fe K-edge X-ray absorption near edge structure (XANES) revealed that the Fe3+ intensity increases as the color of the shell changes from yellow to black. Raman spectra suggested that quinone-based polymers cover the yellow shell, and the black shell is further covered by dihydroxyphenylalanine (DOPA) rings of amino acid derivatives. From Fe K-edge extended X-ray absorption fine structure (EXAFS), it was found that Fe3+ in the periostracum was surrounded by five to six oxygen atoms with an average Fe-O ligand distance of 2.0 Å. Accordingly, a tris-DOPA-Fe3+ complex is formed, which is responsible for the periostracum's black color.
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Affiliation(s)
- Kuniko Takemoto
- Department of Physics, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010, Japan.
| | - Masataka Murakami
- Toray Research Center, Inc., 3-3-7, Sonoyama, Otsu, Shiga 520-8567, Japan
| | - Masao Tabuchi
- Synchrotron Radiation Research Center, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan
| | - Toshiaki Ohta
- The SR Center, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan
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3
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Yanagida T, Asai N, Yamamoto M, Sugahara K, Fujiwara T, Shirakashi S, Yokoyama H. Molecular and morphological description of a novel microsporidian Inodosporus fujiokai n. sp. infecting both salmonid fish and freshwater prawns. Parasitology 2022; 150:1-14. [PMID: 36226572 PMCID: PMC10090623 DOI: 10.1017/s003118202200141x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/30/2022] [Accepted: 09/30/2022] [Indexed: 11/05/2022]
Abstract
A new microsporidian disease of cultured rainbow trout Oncorhynchus mykiss has recently been confirmed in Japan, and the causative species was tentatively designated as Microsporidium sp. RBT-2021. Involvement of common prawn Palaemon paucidens in its transmission was suggested based on the previous feeding trials, although the microsporidian infection in P. paucidens was not confirmed. In this study, P. paucidens in Lake Biwa, Japan was investigated for microsporidian infection and 4 types of spores (types 1-4) were newly found. The nucleotide sequence of the small subunit ribosomal RNA gene was identical between type 1 and Microsporidium sp. RBT-2021, indicating they are conspecific. However, intriguingly, the spore morphology and the mode of development in fish and prawn were strikingly different. Morphological observations revealed type 1 in the prawn possesses characteristics of the genus Inodosporus Overstreet and Weidner, 1974, while Microsporidium sp. RBT-2021 in the trout exhibited the characteristics of the genus Kabatana Lom, Dyková and Tonguthai, 2000. In the phylogeny, type 1 was placed within a clade comprising Kabatana spp. and Inodosporus octosporus. Based on the morphological and molecular analyses, we describe Microsporidium sp. RBT-2021 as Inodosporus fujiokai n. sp. Together with the success of the previous prawn-feeding trials, this study strongly suggests I. fujiokai n. sp. has a multi-host life cycle utilizing fish and crustacean hosts and different modes of development in each host. Such polymorphic life cycle has barely been known among fish microsporidians. This study also suggests that the genus Kabatana is a junior synonym of the genus Inodosporus.
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Affiliation(s)
- Tetsuya Yanagida
- Laboratory of Parasitology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8511, Japan
| | - Nanami Asai
- Aquaculture Research Institute, Kindai University, Wakayama 649-2211, Japan
| | - Michitaka Yamamoto
- Shiga Prefecture Fisheries Management Division, Otsu, Shiga 520-8577, Japan
- Shiga Prefectural Fisheries Experiment Station, Shiga 522-0057, Japan
| | - Kazuhiro Sugahara
- Shiga Prefectural Fisheries Experiment Station, Shiga 522-0057, Japan
| | - Takuto Fujiwara
- Laboratory of Parasitology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8511, Japan
| | - Sho Shirakashi
- Aquaculture Research Institute, Kindai University, Wakayama 649-2211, Japan
| | - Hiroshi Yokoyama
- Faculty of Veterinary Medicine, Okayama University of Science, Ehime 794-8555, Japan
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Nakanishi K, Yokomizo H, Fukaya K, Kadoya T, Matsuzaki SIS, Nishihiro J, Kohzu A, Hayashi TI. Inferring causal impacts of extreme water-level drawdowns on lake water clarity using long-term monitoring data. Sci Total Environ 2022; 838:156088. [PMID: 35605866 DOI: 10.1016/j.scitotenv.2022.156088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/20/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Although long-term ecosystem monitoring provides essential knowledge for practicing ecosystem management, analyses of the causal effects of ecological impacts from large-scale observational data are still in an early stage of development. We used causal impact analysis (CIA)-a synthetic control method that enables estimation of causal impacts from unrepeated, long-term observational data-to evaluate the causal impacts of extreme water-level drawdowns during summer on subsequent water quality. We used more than 100 years of transparency and water level monitoring data from Lake Biwa, Japan. The results of the CIA showed that the most extreme drawdown in recorded history, which occurred in 1994, had a significant positive effect on transparency (a maximum increase of 1.75 m on average over the following year) in the north basin of the lake. The extreme drawdown in 1939 was also shown to be a trigger for an increase in transparency in the north basin, whereas that in 1984 had no significant effects on transparency. In the south basin, contrary to the pattern in the north basin, the extreme drawdown had a significant negative effect on transparency shortly after the extreme drawdown. These different impacts of the extreme drawdowns were considered to be affected by the timing and magnitude of the extreme drawdowns and the depths of the basins. Our approach of inferring the causal impacts of past events on ecosystems will be helpful in implementing water-level management for ecosystem management and improving water quality in lakes.
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Affiliation(s)
- Kosuke Nakanishi
- Health and Environmental Risk Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
| | - Hiroyuki Yokomizo
- Health and Environmental Risk Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Keiichi Fukaya
- Biodiversity Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Taku Kadoya
- Biodiversity Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Shin-Ichiro S Matsuzaki
- Biodiversity Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Jun Nishihiro
- Center for Climate Change Adaptation, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Ayato Kohzu
- Regional Environment Conservation Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Takehiko I Hayashi
- Social Systems Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
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Ma CY, Sugie Y, Yu Z, Okuno Y, Tanaka H, Ihara M. Occurrence of E. coli and antibiotic-resistant E. coli in the southern watershed of Lake Biwa, including in wastewater treatment plant effluent and inflow rivers. Chemosphere 2022; 301:134372. [PMID: 35314177 DOI: 10.1016/j.chemosphere.2022.134372] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 03/14/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
The emergence of antibiotic-resistant bacteria (ARB) and their antibiotic resistance genes (ARGs) poses a serious challenge to human, animal, and environmental health worldwide. ARB can spread into the environment via various sources and routes. In this study, we investigated the occurrence of antibiotic-resistant E. coli in the southern watershed of Lake Biwa. Two-year monitoring of antibiotic-resistant E. coli was carried out in the southern part of Lake Biwa and inflow rivers and at three WWTPs around the southern part of the lake. Concentrations of E. coli in waters that are resistant to ampicillin (AMP), cefotaxime (CTX), ceftazidime (CAZ), levofloxacin (LVFX), tetracycline (TC), and amikacin (AMK) were measured using the culture method. Of these antibiotic-resistant E. coli, AMP-resistant E. coli were found at the highest prevalence, followed by LVFX, CTX, CAZ, TC, and AMK-resistant in both the influent and effluent of WWTPs. These resistance patterns in wastewater are the same as those in clinical samples in Japan. The numbers of antibiotic-resistant E. coli decreased by around a factor of 1000 during the wastewater treatment processes, but the rates clearly increased, suggesting that selection for antibiotic resistance might occur during the wastewater treatment process. AMP-resistant and TC-resistant E. coli were also detected in Lake Biwa and inflow rivers, which suggests that antibiotic resistance might come from not only WWTPs but also livestock farms and small-scale wastewater treatment facilities located in the river catchment.
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Affiliation(s)
- Chih-Yu Ma
- Research Center for Environmental Quality Management, Kyoto University, Shiga, 520-0811, Japan; Louis Pasteur Center for Medical Research, Kyoto, 606-8225, Japan.
| | - Yoshinori Sugie
- Research Center for Environmental Quality Management, Kyoto University, Shiga, 520-0811, Japan
| | - Zaizhi Yu
- Research Center for Environmental Quality Management, Kyoto University, Shiga, 520-0811, Japan
| | - Yoshiki Okuno
- Research Center for Environmental Quality Management, Kyoto University, Shiga, 520-0811, Japan
| | - Hiroaki Tanaka
- Research Center for Environmental Quality Management, Kyoto University, Shiga, 520-0811, Japan
| | - Masaru Ihara
- Research Center for Environmental Quality Management, Kyoto University, Shiga, 520-0811, Japan; Department of General Affairs, Monobe General Affairs Division, Kochi University, Kochi, 783-8502, Japan.
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Kokita T, Ueno K, Yamasaki YY, Matsuda M, Tabata R, Nagano AJ, Mishina T, Watanabe K. Gudgeon fish with and without genetically determined countershading coexist in heterogeneous littoral environments of an ancient lake. Ecol Evol 2021; 11:13283-13294. [PMID: 34646469 PMCID: PMC8495823 DOI: 10.1002/ece3.8050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/02/2021] [Accepted: 08/09/2021] [Indexed: 11/16/2022] Open
Abstract
Countershading, characterized by a darker dorsal surface and lighter ventral surface, is common among many animals. This dorsoventral pigment polarity is often thought to be adaptive coloration for camouflage. By contrast, noncountershaded (melanistic) morphs often occur within a species due to genetic color polymorphism in terrestrial animals. However, the polymorphism with either countershaded or melanistic morphs is poorly known in wild aquatic animals. This study explored the genetic nature of diverged color morphs of a lineage of gudgeon fish (genus Sarcocheilichthys) in the ancient Lake Biwa and propose this system as a novel model for testing hypotheses of functional aspects of countershading and its loss in aquatic environments. This system harbors two color morphs that have been treated taxonomically as separate species; Sarcocheilichthys variegatus microoculus which occurs throughout the littoral zone and Sarcocheilichthys biwaensis which occurs in and around rocky areas. First, we confirmed that the divergence of dorsoventral color patterns between the two morphs is under strict genetic control at the levels of chromatophore distribution and melanin-related gene expression under common garden rearing. The former morph displayed sharp countershading coloration, whereas the latter morph exhibited a strong tendency toward its loss. The crossing results indicated that this divergence was likely controlled by a single locus in a two-allele Mendelian inheritance pattern. Furthermore, our population genomic and genome-wide association study analyses detected no genome-wide divergence between the two morphs, except for one region near a locus that may be associated with the color divergence. Thus, these morphs are either in a state of intraspecific color polymorphism or two incipient species. Evolutionary forces underlying this polymorphism appear to be associated with heterogeneous littoral environments in this lake. Future ecological genomic research will provide insight into adaptive functions of this widespread coloration, including the eco-evolutionary drivers of its loss, in the aquatic world.
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Affiliation(s)
- Tomoyuki Kokita
- Faculty of Marine Science and TechnologyFukui Prefectural UniversityObamaJapan
| | - Kohtaro Ueno
- Faculty of Marine Science and TechnologyFukui Prefectural UniversityObamaJapan
| | | | | | | | - Atsushi J. Nagano
- Faculty of AgricultureRyukoku UniversityOtsuJapan
- Institute for Advanced BiosciencesKeio UniversityTsuruokaJapan
| | - Tappei Mishina
- Laboratory for Chromosome SegregationRIKEN Center for Biosystems Dynamics ResearchKobeJapan
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Kishimoto Y, Okuyama H, Takahashi JI. Complete mitochondrial DNA sequence of the Japanese endemic catfish Silurus biwaensis (Siluriformes: Siluridae) from Lake Biwa. Mitochondrial DNA B Resour 2021; 6:2482-2483. [PMID: 34395882 PMCID: PMC8354177 DOI: 10.1080/23802359.2021.1920487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The Japanese endemic catfish Silurus biwaensis is distributed only in Lake Biwa and Yodo river drainages. There are four species of the genus Silurus in Japan, of which S. biwaensis has a most limited distribution. This catfish needs to be collected for DNA data owing to the lack of information related to its phylogenetic relationship. Here, the complete mitochondrial genome of the S. biwaensis from Lake Biwa in Japan was analyzed using next-generation sequencing. The mitochondrial genome of S. biwaensis was identified as a 16,531 bp circular molecule containing 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes, along with one A + T-rich control region. The AT content was 55.83%. The heavy (H)-strand was predicted to have 12 PCGs, 14 tRNA, and 2 rRNA genes, whereas the light (L)-strand was predicted to contain one PCG and eight tRNA genes. The start codons ATG, ATC, and GTG were found in 13 PCGs. The stop codons TAA, TAG, and AGA were observed in all PCGs, except CytB and COX3. All tRNA genes formed typical cloverleaf secondary structures. The molecular phylogenetic relationships estimated using 13 PCGs (maximum-likelihood method) indicated that S. biwaensis is genetically distinct from the sympatric species S. asotus and S. lithophilus. This result clearly indicated that S. biwaensis is a valid species.
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Affiliation(s)
- Yuu Kishimoto
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
| | - Hisashi Okuyama
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
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Kishimoto Y, Okuyama H, Takahashi JI. Complete mitochondrial DNA sequence of the Japanese endemic catfish Silurus lithophilus (Siluriformes: Siluridae). Mitochondrial DNA B Resour 2021; 6:2559-2561. [PMID: 34377829 PMCID: PMC8344260 DOI: 10.1080/23802359.2021.1920486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Japanese endemic catfish Silurus lithophilus is distributed only in Lake Biwa, Lake Yogo, and their river drainages. There are four species of the genus Silurus in Japan, of which S. lithophilus has a limited distribution. This catfish needs to be collected for DNA data owing to the lack of information related to its conservation. Here, the complete mitochondrial genome of the S. lithophilus from Lake Biwa in Japan was analyzed using next-generation sequencing. The mitochondrial genome of S. lithophilus was identified as a 16,524 bp circular molecule containing 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes, along with one A + T-rich control region. The AT content was 55.89%. The heavy (H)-strand was predicted to have 12 PCGs and 15 tRNA, and 2 rRNA genes, whereas the light (L)-strand was predicted to contain one PCG and seven tRNA genes. The start codons ATG and GTG were found in 13 PCGs. The stop codons TAA, TAG, and AGA were observed in all PCGs, except CytB. All tRNA genes formed typical cloverleaf secondary structures. The molecular phylogenetic relationship, inferred using 13 PCGs (based on the maximum likelihood), was consistent with that reported in previous studies, which predicted a sister relationship between S. lithophilus and S. asotus. The results also clearly indicated that S. lithophilus is a valid species.
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Affiliation(s)
- Yuu Kishimoto
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
| | - Hisashi Okuyama
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
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Mabuchi K, Nishida K, Nakajima N. Complete F mitochondrial genomes of two freshwater mussels from the Lake Biwa system in Japan: Beringiana fukuharai and Sinanodonta tumens. Mitochondrial DNA B Resour 2021; 6:2491-2493. [PMID: 34368451 PMCID: PMC8317961 DOI: 10.1080/23802359.2021.1955762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We determined the complete mitochondrial sequences of female-transmitted (F) mitogenomes of six unionid specimens from the Lake Biwa system, Japan. Their gene contents and orders agreed with those of the typical F mitogenome of freshwater mussels. Molecular phylogenetic analysis using fifteen previously identified partial COI and 12 (six previously identified and six newly determined) whole mitogenome sequences revealed that five of the six mitogenomes (LC592401, LC592402, LC592403, LC592408, and LC592410) were those of Beringiana fukuharai, while the remaining one (LC592406) was Sinanodonta tumens.
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Affiliation(s)
- Kohji Mabuchi
- Lake Biwa Branch Office, National Institute for Environmental Studies, Otsu, Japan
| | - Kazuya Nishida
- Lake Biwa Branch Office, National Institute for Environmental Studies, Otsu, Japan
| | - Nobuyoshi Nakajima
- Environmental Genomics Office, National Institute for Environmental Studies, Tsukuba, Japan
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Mabuchi K, Nishida K, Nakajima N. Complete female-transmitted mitochondrial genomes of two freshwater mussels from the Lake Biwa system in Japan: Nodularia douglasiae and N. nipponensis. Mitochondrial DNA B Resour 2021; 6:1536-1538. [PMID: 33969212 PMCID: PMC8078931 DOI: 10.1080/23802359.2021.1914218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We determined the complete mitochondrial sequences of female-transmitted (F) mitogenomes of two unionid specimens from the Lake Biwa system, Japan. Their gene contents and orders agreed with those of the typical F mitogenome of freshwater mussels. Molecular phylogenetic analysis using 20 previously identified partial COI and seven (five previously identified and two newly determined) whole mitogenome sequences revealed that one of the two mitogenomes was that of Nodularia douglasiae, while the other was N. nipponensis.
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Affiliation(s)
- Kohji Mabuchi
- Lake Biwa Branch Office, National Institute for Environmental Studies, Otsu, Japan
| | - Kazuya Nishida
- Lake Biwa Branch Office, National Institute for Environmental Studies, Otsu, Japan
| | - Nobuyoshi Nakajima
- Environmental Genomics Office, National Institute for Environmental Studies, Tsukuba, Japan
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Sawada N, Nakano T. Revisiting a 135-year-old Taxonomic Account of the Freshwater Snail Semisulcospira multigranosa: Designating its Lectotype and Describing a New Species of the genus (Mollusca: Gastropoda: Semisulcospiridae). Zool Stud 2021; 60:e7. [PMID: 34394756 DOI: 10.6620/ZS.2021.60-07] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/01/2021] [Indexed: 12/23/2022]
Abstract
The type series of Semisulcospira multigranosa Boettger, 1886 was found in the Malacological Collection at the Senckenberg Naturmuseum for the first time ca. 135 years after its original description. The syntypes consisted of 38 specimens that can be classified into four species. The examination of adult shell morphology of these original materials revealed that the current taxonomic account of S. multigranosa should be amended. Therefore, we designate a lectotype for S. multigranosa, and thus describe S. multigranosa auct. as Semisulcospira davisi sp. nov. Semisulcospira davisi can be discriminated from the other congeners by the characteristics of adult and embryonic shells, and radulae morphology. The present study resolves one of the fundamental taxonomic problems remaining in Semisulcospira snails.
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Yamada E, Sasai K, Higa R, Mizuguchi H, Fuse Y. Characterization and Dynamic Analysis of Dissolved Proteins in Lake Biwa Using Two-Dimensional Electrophoresis. ANAL SCI 2020; 36:753-759. [PMID: 31956160 DOI: 10.2116/analsci.19p450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Concentrated protein-like fluorophores of dissolved organic matter (DOM) in Lake Biwa were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis (2-DE). As a result, it was found that the protein-like fluorophores in Lake Biwa are likely to be dissolved proteins released from phytoplankton. SDS-PAGE analysis revealed that protein-like fluorophores from Lake Biwa usually consist of proteins with molecular weights of 33 - 35, 42 - 45, 56 - 59 and 62 - 66 kDa. The molecular weights (MWs) and isoelectric points (pIs) of dissolved proteins in Lake Biwa were firstly clarified using 2-DE. The 2-DE patterns of proteins in Lake Biwa were compared with those for algal DOM released from four kinds of lake phytoplankton, Microcystis aeruginosa, Staurastrum dorsidentiferum, Cryptomonas ovata, and Fragilaria capucina. Some of the protein spots in 2-DE of Lake Biwa were similar to those of algal DOM released during cultivation. The relations between monthly changes in the electrophoretic gel images of lake water samples and those in the community structure of phytoplankton in Lake Biwa were observed. These results suggest that some of the dissolved proteins in Lake Biwa are likely derived from phytoplankton.
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Affiliation(s)
| | - Keisuke Sasai
- Department of Chemistry and Material Technology, Kyoto Institute of Technology
| | - Ryota Higa
- Department of Chemistry and Material Technology, Kyoto Institute of Technology
| | - Hirotaka Mizuguchi
- Department of Chemistry and Material Technology, Kyoto Institute of Technology
| | - Yasuro Fuse
- Department of Chemistry and Material Technology, Kyoto Institute of Technology.,Center for Environmental Science, Kyoto Institute of Technology
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Misaki K, Matsuda S, Matsuda T, Kusakabe T, Shimizu Y. Detection of DNA damage formation by natural organic matter using EGFP-fused MDC1-expressing cells. Chemosphere 2019; 235:169-174. [PMID: 31255757 DOI: 10.1016/j.chemosphere.2019.06.126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 06/13/2019] [Accepted: 06/17/2019] [Indexed: 06/09/2023]
Abstract
Studies have been conducted on the genotoxicity and carcinogenicity of disinfection by-products formed from natural organic matter (NOM) and mitigation effect for mutagens and clastogens by NOM. Whereas, reportedly, synthetic humic acid in high concentration has induced genotoxicity in human cells, and NOM samples have provoked mild oxidative and other physiological responses in aquatic organisms. Our group developed a novel detection method for DNA damage formation, namely enhanced green fluorescent protein (EGFP)-fused mediator of DNA damage checkpoint 1 (MDC1)-expressing human cells as simple and high-sensitive system. By using this method, a significant increase in the foci area was observed after 3 h, but not 24 h for 130 mgC L-1 Suwannee River fulvic acid (SRFA), 38 mgC L-1 humic acid (SRHA), and 19 mgC L-1 NOM (SRNOM). The SRNOM concentration is the original environmental one; therefore, it was suggested that the formation and repair of DNA damage associated with γ-H2AX, a biomarker for DNA double-strand breaks by mild oxidative stress, in Suwannee River (SR) were detected for the first time. The increase in the foci area was not observed for 18 mgC L-1 Lake Biwa fulvic acid (LBFA) and 50 mg L-1 catechin after both 3 h and 24 h. The difference between the SR and Lake Biwa (LB) samples may result from the differences in their electron-accepting capacity. The application of this methodology is expected to elucidate oxidative stress and toxicological effects shortly and in detail for many water samples.
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Affiliation(s)
- Kentaro Misaki
- Research Center for Environmental Quality Management (RCEQM), Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, Japan; School of Nursing, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, Japan.
| | - Shun Matsuda
- Research Center for Environmental Quality Management (RCEQM), Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, Japan
| | - Tomonari Matsuda
- Research Center for Environmental Quality Management (RCEQM), Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, Japan
| | - Taketoshi Kusakabe
- Research Center for Environmental Quality Management (RCEQM), Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, Japan
| | - Yoshihisa Shimizu
- Research Center for Environmental Quality Management (RCEQM), Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, Japan
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Misaki K, Morita Y, Kobayashi K, Sugawara Y, Shimizu Y, Kusakabe T. Evaluation of algal photosynthesis inhibition activity for dissolved organic matter with the consideration of inorganic and coloring constituents. Chemosphere 2019; 224:333-342. [PMID: 30826703 DOI: 10.1016/j.chemosphere.2019.02.106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/15/2019] [Accepted: 02/16/2019] [Indexed: 06/09/2023]
Abstract
The effect of waterborne ingredient on ecosystem has been of great interest. In the present study, the evaluation method using algal photosynthesis inhibition assay with dual-channel pulse amplitude modulation (PAM) system was established for a series of water samples to elucidate the potential effect of the total body of organic compounds including natural organic matter (NOM) on aquatic ecosystems. The more sensitive and less time-consuming monitoring method compared with algal growth inhibition assay was suggested, especially considering inorganic and coloring constituents. Algal photosynthesis inhibition activity was detected with high sensitivity for photosystem II (PSII) inhibitors, whereas the IC10 of the other chemicals was over the environmental standard concentration for Chlamydomonas moewusii (Chlorophyceae) and Pheodactylum tricornutum (Diatomea). The photosynthesis inhibition activity of Lake Biwa dissolved organic matter (LBDOM) and fulvic acid (LBFA) was significantly detected at ≥10 times the concentration and >10 mgC L-1, respectively, whereas prominent activity was confirmed for Suwannee River NOM (SRNOM) on the river original concentration (>30 mgC L-1) for both algae. Significant inhibition activity was detected in both algae at least in twice-concentration for water samples from a wastewater treatment pilot plant. There was no great difference in the activity between sewage secondary effluent and its filtrate with ultrafiltration (UF), and physically washing water for the UF membrane.
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Affiliation(s)
- Kentaro Misaki
- Research Center for Environmental Quality Management (RCEQM), Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, Japan; School of Nursing, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, Japan.
| | - Yuhei Morita
- Research Center for Environmental Quality Management (RCEQM), Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, Japan
| | - Kentaro Kobayashi
- Global Environmental Research Laboratories, Toray Industries, Inc., 3-2-1 Sonoyama, Otsu, Shiga, Japan
| | - Yuichi Sugawara
- Water Treatment Technical Dept., Toray Industries, Inc., 3-3-3 Sonoyama, Otsu, Shiga, Japan
| | - Yoshihisa Shimizu
- Research Center for Environmental Quality Management (RCEQM), Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, Japan.
| | - Taketoshi Kusakabe
- Research Center for Environmental Quality Management (RCEQM), Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga, Japan.
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Maruyama A, Sugatani K, Watanabe K, Yamanaka H, Imamura A. Environmental DNA analysis as a non-invasive quantitative tool for reproductive migration of a threatened endemic fish in rivers. Ecol Evol 2018; 8:11964-11974. [PMID: 30598791 PMCID: PMC6303803 DOI: 10.1002/ece3.4653] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/20/2018] [Accepted: 09/25/2018] [Indexed: 12/22/2022] Open
Abstract
Quantitative information regarding reproduction is essential for conserving endangered animals; however, some conventional quantitative methods can be damaging to the target population and their habitats. In the present study, the reproductive migration of a threatened endemic fish, three-lips (Opsariichthys uncirostris uncirostris), was non-invasively monitored by quantitative PCR of species-specific environmental DNA (eDNA), the usefulness of which has been not sufficiently explored. Water sampling and from-shore visual inspection were performed weekly along a tributary of Lake Biwa (Japan), where adult fish seasonally migrate upstream to reproduce as well as at lake sites near the river mouth. Species-specific eDNA was collected at all locations at times when the fish were visually observed and at certain sites where the fish were not observed. Log-transformed individual counts from visual inspection were positively correlated with log-transformed eDNA concentration in the river sites, indicating that eDNA analysis can be a reliable quantitative tool for fish abundance in rivers. Furthermore, distance from the lake did not influence eDNA concentration, suggesting that eDNA transport by river flow had a negligible effect on eDNA quantification. Both eDNA concentration and individual counts gradually increased from May-July, and decreased in August. Importantly, eDNA analysis showed that the fish occupied more habitats in the peak reproductive season and stayed for longer time at any given site. An additional underwater survey confirmed unexpected eDNA detections as true positives. eDNA analysis has great potential to quantitatively monitor reproductive fish migrations under certain conditions.
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Affiliation(s)
- Atsushi Maruyama
- Faculty of Science and TechnologyRyukoku UniversityOtsuShigaJapan
| | - Kousuke Sugatani
- Faculty of Science and TechnologyRyukoku UniversityOtsuShigaJapan
| | - Kazuki Watanabe
- Faculty of Science and TechnologyRyukoku UniversityOtsuShigaJapan
| | - Hiroki Yamanaka
- Faculty of Science and TechnologyRyukoku UniversityOtsuShigaJapan
| | - Akio Imamura
- Hokkaido University of EducationAsahikawaHokkaidoJapan
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Abstract
The Japanese clouded salamander (Hynobius nebulosus) is a lentic-breeding species distributed throughout western Japan. Threats, such as habitat loss, have led to it being categorized as a vulnerable species. To explore the phylogeographic features and population differentiation among clouded salamanders in Shiga prefecture, we analyzed sequences of the mitochondrial cytochrome b gene. DNA samples were collected from 29 distinct breeding sites, and 53 cytochrome b haplotypes were identified. On the basis of comparison of the composition and frequency of haplotypes in each breeding site, salamanders in each habitat appeared to have distinct characteristics. Significant genetic differentiation was observed in 93.3% of possible pairs of habitats in Shiga prefecture, and 67.7% of habitat pairs within the same locality were found to be significantly different. These results suggest that the salamanders' poor locomotion combined with topographic effects may have contributed to the diversity of locally distributed salamanders in Shiga. Phylogenetic analysis showed that haplotypes of H. nebulosus in Shiga can be divided into five groups (the Nagahama-Maibara group, Otsu group, Konan group 1, Konan group 2, and Takashima group), each with a distinct geographical distribution. Haplotypes of the Otsu group, however, were exceptionally widely distributed. The results of the present study will contribute to the future of H. nebulosus conservation management in Shiga.
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Affiliation(s)
- Naoki Mito
- 1 Department of Animal Bio-Science, Faculty of Bio-Science, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-cho, Nagahama-shi, Shiga 526-0829, Japan
| | - Kazuhiko Ohshima
- Department of Computer Bio-Science, Faculty of Bio-Science, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-cho, Nagahama-shi, Shiga 526-0829, Japan
| | - Osamu Saitoh
- 1 Department of Animal Bio-Science, Faculty of Bio-Science, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-cho, Nagahama-shi, Shiga 526-0829, Japan
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Tsuji K, Asayama T, Shiraki N, Inoue S, Okuda E, Hayashi C, Nishida K, Hasegawa H, Harada E. Mn accumulation in a submerged plant Egeria densa (Hydrocharitaceae) is mediated by epiphytic bacteria. Plant Cell Environ 2017; 40:1163-1173. [PMID: 28098343 DOI: 10.1111/pce.12910] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 12/24/2016] [Accepted: 01/04/2017] [Indexed: 06/06/2023]
Abstract
Many aquatic plants act as biosorbents, removing and recovering metals from the environment. To assess the biosorbent activity of Egeria densa, a submerged freshwater macrophyte, plants were collected monthly from a circular drainage area in Lake Biwa basin and the Mn concentrations of the plants were analysed. Mn concentrations in these plants were generally above those of terrestrial hyperaccumulators, and were markedly higher in spring and summer than in autumn. Mn concentrations were much lower in plants incubated in hydroponic medium at various pH levels with and without Mn supplementation than in field-collected plants. The precipitation of Mn oxides on the leaves was determined by variable pressure scanning electron microscopy-energy dispersive X-ray analysis and Leucoberbelin blue staining. Several strains of epiphytic bacteria were isolated from the field-collected E. densa plants, with many of these strains, including those of the genera Acidovorax, Comamonas, Pseudomonas and Rhizobium, found to have Mn-oxidizing activity. High Mn concentrations in E. densa were mediated by the production of biogenic Mn oxide in biofilms on leaf surfaces. These findings provide new insights into plant epidermal bacterial flora that affect metal accumulation in plants and suggest that these aquatic plants may have use in Mn phytomining.
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Affiliation(s)
- Kousuke Tsuji
- Graduate School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Takuma Asayama
- Graduate School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Nozomi Shiraki
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Shota Inoue
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Erina Okuda
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Chizuru Hayashi
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Kazuma Nishida
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Hiroshi Hasegawa
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
| | - Emiko Harada
- School of Environmental Science, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga, 522-8533, Japan
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Chen X, Chen Y, Shimizu T, Niu J, Nakagami K, Qian X, Jia B, Nakajima J, Han J, Li J. Water resources management in the urban agglomeration of the Lake Biwa region, Japan: An ecosystem services-based sustainability assessment. Sci Total Environ 2017; 586:174-187. [PMID: 28185732 DOI: 10.1016/j.scitotenv.2017.01.197] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/30/2017] [Accepted: 01/30/2017] [Indexed: 06/06/2023]
Abstract
An innovative ecosystem services-based sustainability assessment was conducted in the important urban agglomeration of the Lake Biwa region, Japan, covering the time period from 1950 to 2014. A 22-indicator system was established that was based on the major ecosystem services of Lake Biwa and its water courses, i.e., provisioning services regarding aquatic products and water; regulating services regarding floods and water quality; cultural services regarding recreation and tourism, scientific research, and environmental education; and supporting services regarding biodiversity. First, changes in the eight ecosystem services were discussed together with the considerable experience and difficult lessons that can be drawn from the development trajectory. Next, with the indicators rearranged according to sustainability principles, the regional sustainability over the past six-plus decades was assessed. In general, this urban agglomeration has been progressing in terms of its sustainability, although economic and social development was achieved at the cost of environmental degradation in the past, and the current economic downturn is hurting the balanced development and integrated benefits. The results lead directly to recommendations for regional development, especially in terms of economic rejuvenation, from the perspective of improving management of Lake Biwa's water resources. Moreover, the relevant knowledge is educational and inspirational for other places in the world that are facing similar development issues. For example, the effective and even pioneering countermeasures that have been taken against environmental degradation, as well as the participation and collaboration of multiple stakeholders, could be useful as a model. Moreover, the study invites increased understanding of ecosystem vulnerability to anthropogenic devastation and emphasizes the priority of precautionary measures over countermeasures in the context of holistic urban planning and sustainable urban development.
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Affiliation(s)
- Xiaochen Chen
- College of Environment and Resources, Fuzhou University, No. 2 Xueyuan Road, Fuzhou, Fujian 350116, China; Ritsumeikan-Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan
| | - Yuqing Chen
- College of Environment and Resources, Fuzhou University, No. 2 Xueyuan Road, Fuzhou, Fujian 350116, China
| | - Toshiyuki Shimizu
- Ritsumeikan-Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan
| | - Jia Niu
- College of Ecological Environment and Urban Construction, Fujian University of Technology, No. 3 Xueyuan Road, Fuzhou, Fujian 350118, China; Ritsumeikan Research Center for Sustainability Science, Ritsumeikan University, 2-150 Iwakura-cho, Ibaraki, Osaka 567-8570, Japan.
| | - Ken'ichi Nakagami
- College of Policy Science, Ritsumeikan University, 2-150 Iwakura-cho, Ibaraki, Osaka 567-8570, Japan; Integrated Research System for Sustainability Science, Todai Institutes for Advanced Study, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Xuepeng Qian
- College of Asia Pacific Studies, Ritsumeikan Asia Pacific University, 1-1 Jumonjibaru, Beppu, Oita 874-8577, Japan
| | - Baoju Jia
- Ritsumeikan-Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan
| | - Jun Nakajima
- College of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan
| | - Ji Han
- School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Jianhua Li
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
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Tabata R, Kakioka R, Tominaga K, Komiya T, Watanabe K. Phylogeny and historical demography of endemic fishes in Lake Biwa: the ancient lake as a promoter of evolution and diversification of freshwater fishes in western Japan. Ecol Evol 2016; 6:2601-23. [PMID: 27066244 PMCID: PMC4798153 DOI: 10.1002/ece3.2070] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/16/2016] [Accepted: 02/22/2016] [Indexed: 01/21/2023] Open
Abstract
To elucidate the origins of the endemic fish of Lake Biwa, an ancient lake in Japan, and the role of the lake in the diversification of freshwater fish in western Japan, we established a molecular phylogenetic framework with an absolute time scale and inferred the historical demography of a large set of fish species in and around the lake. We used mtDNA sequences obtained from a total of 190 specimens, including 11 endemic species of Lake Biwa and their related species, for phylogenetic analyses with divergence time estimations and from a total of 2319 specimens of 42 species (including 14 endemics) occurring in the lake for population genetic analyses. Phylogenetic analysis suggested that some of the endemic species diverged from their closest relatives earlier (1.3–13.0 Ma) than the period in which the present environmental characteristics of the lake started to develop (ca. 0.4 Ma), whereas others diverged more recently (after 0.4 Ma). In contrast, historical demographic parameters suggested that almost all species, including endemic and nonendemic ones, expanded their populations after the development of the present lake environment. In phylogeographic analyses, common or very close haplotypes of some species were obtained from Lake Biwa and other regions of western Japan. The phylogenetic and historical demographic evidence suggests that there was a time lag between phylogenetic divergence and population establishment and that phenotypic adaptation of some endemic species to the limnetic environment occurred much later than the divergences of those endemic lineages. Population structure and phylogeographic patterns suggest that Lake Biwa has functioned not only as the center of adaptive evolution but also as a reservoir for fish diversity in western Japan.
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Affiliation(s)
- Ryoichi Tabata
- Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo Kyoto 606-8502 Japan
| | - Ryo Kakioka
- Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo Kyoto 606-8502 Japan; Research Institute for Humanity and Nature 457-4 Kamigamo-Motoyama Kita-ku Kyoto 603-8047 Japan
| | - Koji Tominaga
- Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo Kyoto606-8502 Japan; Kwansei Gakuin Senior High School 1-155 Uegahara-ichibancho Nishinomiya Hyogo 662-8501 Japan
| | - Takefumi Komiya
- Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo Kyoto 606-8502 Japan
| | - Katsutoshi Watanabe
- Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo Kyoto 606-8502 Japan
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Ito T, Kurita J, Yuasa K. Differences in the susceptibility of Japanese indigenous and domesticated Eurasian common carp (Cyprinus carpio), identified by mitochondrial DNA typing, to cyprinid herpesvirus 3 (CyHV-3). Vet Microbiol 2014; 171:31-40. [PMID: 24690375 DOI: 10.1016/j.vetmic.2014.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 02/24/2014] [Accepted: 03/03/2014] [Indexed: 11/20/2022]
Abstract
In 2004, a massive mortality of wild common carp (Cyprinus carpio) due to CyHV-3 infection occurred in Lake Biwa. Although common carp of two different mitochondrial types (Japanese indigenous and domesticated Eurasian) occur in the lake, the majority of the dead fish seemed to be the indigenous type. The apparent high mortality in the indigenous type implies a higher susceptibility of this type to CyHV-3. To test the hypothesis that the susceptibility of indigenous and Eurasian types differ, we performed experimental infections with CyHV-3 among 2 groups of the indigenous type, and for the Eurasian type 4 groups of domesticated common carp and 4 groups of koi carp. Fish were immersed in CyHV-3 isolate and kept at 24°C. Both groups of the indigenous type died more rapidly compared with the 8 groups of the Eurasian type. Cumulative mortality in both indigenous groups reached 95-100%, whereas the cumulative mortalities of domesticated common carp (30-95%) and koi carp (35-100%) were more varied. CyHV-3 genome in the organs of the indigenous type increased more rapidly after the viral exposure and reached higher peak levels than those of the domesticated strain. These findings revealed that susceptibility of the indigenous type of carp to CyHV-3 can be considered especially high.
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Araki KS, Nakazawa T, Kawakita A, Kudoh H, Okuda N. Development of nine markers and characterization of the microsatellite loci in the endangered Gymnogobius isaza (Gobiidae). Int J Mol Sci 2012; 13:5700-5. [PMID: 22754324 DOI: 10.3390/ijms13055700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 04/28/2012] [Accepted: 05/07/2012] [Indexed: 11/28/2022] Open
Abstract
Gymnogobius isaza is a freshwater goby endemic to Lake Biwa, Japan. They experienced a drastic demographic bottleneck in the 1950s and 1980s and slightly recovered thereafter, but the population size is still very small. To reveal dynamics of genetic diversity of G. isaza, we developed nine microsatellite markers based on the sequence data of a related goby Chaenogobius annularis. Nine SSR (Simple Sequence Repeats) markers were successfully amplified for raw and formalin-fixed fish samples. The number of alleles and expected heterozygosities ranged from one to 10 and from 0.06 to 0.84, respectively, for the current samples, while one to 12 and 0.09 to 0.83 for historical samples. The markers described here will be useful for investigating the genetic diversity and gene flow and for conservation of G. isaza.
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