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1.
Biomed Res Int ; 2022: 2928235, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35434123

RESUMO

In the present study, we evaluated the effects of different environments on the filtering rate (FR), mortality, and biodeposition (BD) of the freshwater mussel Unio douglasiae in bloom waters containing the toxic cyanobacterium Microcystis aeruginosa. The mean FR of 19 selected individuals (shell length, 5.0-9.8 cm) was 0.30 ± 0.03 L g-1 h-1 (range = 0.24-0.35 L g-1 h-1). Shell length was strongly correlated with both net and gross BD of mussels (P < 0.0001). The mean FR was higher in river water (0.405 ± 0.052 L g-1 h-1) than in lake water (0.304 ± 0.051 L g-1 h-1). In contrast, the BD of mussels was higher in RW (0.671 ± 0.609 mg g-1 h-1) than in LW (0.275 ± 0.027 mg g-1 h-1). For algal species, the FR of mussels ranged from 0.114 ± 0.024 to 0.553 ± 0.019 L g-1 h-1. The FR of U. douglasiae was higher in river water (mainly diatoms), whereas BD was higher in lake water (mainly Microcystis). U. douglasiae did not prefer toxic M. aeruginosa, which was significantly accumulated in pseudofaeces and faeces. The maximum FR of U. douglasiae in algal bloom water was recorded at a water temperature of 25°C and water depth of 50 cm. Moreover, the in situ mortality of U. douglasiae was strongly affected by water temperature and nitrogen concentration. Overall, U. douglasiae can enhance water quality in eutrophic areas by removing dominant cyanobacteria, although its removal efficiency depends on environmental parameters and site of introduction.


Assuntos
Bivalves , Cianobactérias , Microcystis , Unionidae , Animais , Água Doce/microbiologia , Humanos
2.
PLoS One ; 17(3): e0265318, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35312719

RESUMO

Pearl color is an important factor influencing pearl value, and is affected by the nacre color of the shell in Hyriopsis cumingii. Coproporphyrinogen-III oxidase (CPOX) is a key enzyme in porphyrin synthesis, and porphyrins are involved in color formation in different organisms, including in the nacre color of mussels. In this study, a CPOX gene (HcCPOX) was identified from H. cumingii, and its amino acid sequence was found to contain a coprogen-oxidase domain. HcCPOX mRNA was expressed widely in the tissues of white and purple mussels, and the highest expression was found in the gill, followed by the fringe mantle. The expression of HcCPOX in all tissues of purple mussels (except in the middle mantle) was higher than that of white mussels. Strong hybridization signals for HcCPOX were observed in the dorsal epithelial cells of the outer fold of the mantle. The activity of CPOX in the gill, fringe mantle, and foot of purple mussels was significantly higher than that in white mussels. Moreover, the expression of HcCPOX and CPOX activity were decreased in RNA interference experiments. The findings indicate that HcCPOX might contributes to nacre color formation in H. cumingii by being involved in porphyrin synthesis.


Assuntos
Bivalves , Nácar , Unionidae , Animais , Bivalves/genética , Bivalves/metabolismo , Coproporfirinogênio Oxidase/metabolismo , Coproporfirinogênios/metabolismo , Nácar/metabolismo , Oxirredutases/metabolismo , Unionidae/genética
3.
Environ Pollut ; 292(Pt A): 118330, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34634398

RESUMO

River floodplain ecosystems host one of the highest freshwater molluscan biodiversity on Earth. However, multiple human disturbances, such as loss of hydrological connectivity and deterioration of water quality, are seriously threatening most floodplain lakes throughout the world. Given the high imperilment rate of freshwater molluscs but the scarcity of studies examining the anthropogenic effects on this fauna, we test the response of mollusc assemblages to river-lake disconnection and eutrophication in 30 lakes in the Yangtze River floodplain, China. The species richness of entire Mollusca, Gastropoda and Bivalvia and 6 dominant families were all much lower at disconnected lakes than that in connected lakes, and decreased with increasing water eutrophication. The assemblage structure differed significantly among four lake groups for datasets based on entire Mollusca, Gastropoda and Bivalvia, indicating the serious impacts of hydrological disconnection and eutrophication. Moreover, the connected lakes showed significantly lower values of average taxonomic distinctness (Δ+) but higher values of variation in taxonomic distinctness (Λ+) than disconnected lakes. Such variations were triggered by the extirpation of congeneric and endemic species (mainly from families Unionidae and Viviparidae), which giving a waring of the loss of mollusc endemism in this region. In general, the present study showed that river-lake disconnection and deterioration of water quality resulted in serious biodiversity declines of both gastropods and bivalves in the Yangtze River floodplain lakes. A systematic approach including restoration of river-lake connectivity and habitats and improvement of water quality should be implemented in the conservation planning in this large river floodplain.


Assuntos
Lagos , Unionidae , Animais , China , Ecossistema , Eutrofização , Humanos , Rios
4.
Dev Comp Immunol ; 129: 104336, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34921862

RESUMO

The NF-κB pathway activated by bacteria and viruses produces a series of antimicrobial peptides that participate in the innate immune response. In this study, two NF-κB subunits were cloned and identified from Hyriopsis cumingii (named Hcp65 and Hcp105) using RT-PCR and RACE. The predicted Hcp65 protein possessed a N-terminal Rel homology domain (RHD) and an Ig-like/plexins/transcription factors domain (IPT); the Hcp105 contained an RHD, an IPT domain, 6 ankyrin (ANK) domain and a death domain. Quantitative reverse transcription PCR (qRT-PCR) showed that Hcp65 and Hcp105 were constitutively expressed in the detected tissues, and were significantly up-regulated in hemocytes, hepatopancreas and gill of mussels challenged with lipopolysaccharide (LPS), peptidoglycan (PGN) and polyinosinic-polycytidylic acid (poly I: C). The dsRNA-mediated silencing of Hcp65 and Hcp105 caused significant reduction of immune genes such as lysozyme (HcLyso), theromacin (Hcther), whey acid protein (HcWAP), LPS-binding protein/bactericidal permeability protein (HcLBP/BPI) 1 and 2. In addition, subcellular localization experiments showed that Hcp65 and Hcp105 proteins were expressed in both the nucleus and cytoplasm of HEK-293T cells, and Hcp50 proteins (mature peptide of Hcp105) were mainly localized in the nucleus. The recombinant Hcp65 and Hcp50 protein could form homodimer and heterodimer and bind κB site in vitro. These results provide useful information for understanding the role of NF-κB in mollusks.


Assuntos
NF-kappa B/metabolismo , Proteínas de Fase Aguda , Animais , Anti-Infecciosos , Bivalves/imunologia , Proteínas de Transporte , DNA Complementar/genética , Regulação da Expressão Gênica , Hemócitos/metabolismo , Hepatopâncreas/imunologia , Imunidade Inata/genética , Lipopolissacarídeos , Glicoproteínas de Membrana , Muramidase/metabolismo , Peptidoglicano/metabolismo , Filogenia , Fator de Transcrição RelA , Unionidae/imunologia , Vibrio parahaemolyticus/imunologia
5.
Sci Rep ; 11(1): 23755, 2021 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-34887477

RESUMO

The naiads, large freshwater mussels (Unionida), have very long life spans, are large-bodied, and produce thousands to millions of larvae (glochidia) which typically must attach to host fish tissues to metamorphose into a juvenile mussel. Glochidia develop within a female's marsupial gill demibranch, thus their number is restricted by female size. However, larger mussels acquire more energy, which could be invested in either larger-sized glochidia, in a more glochidia, or a combination of both. The high level of host specialization seen in many naiads may constrain glochidial size and shape around a narrow optimum, while naiads that use a wide range of host fishes may be predicted to possess greater plasticity in glochidial morphology. In this paper, we investigated the relationship between maternal body size and progeny body size and shape, aided by modern digital microscopy. We analyzed the between- and within- species variation of glochidia size and shape relative to female size in four widespread species of European naiads: Anodonta anatina, Anodonta cygnea, Unio crassus and Unio tumidus. Whereas the total reproductive output is collinear with female body size, substantial differences between species in glochidia size were found within genus Anodonta, but not genus Unio where glochidial size is remarkably consistent. The glochidial shape, however, differed within both Unio and Anodonta. We interpret this constant within-species glochidial size in Unio as reflecting a constraint imposed by the likelihood of successful transmission onto and off from a narrow range of hosts, whereas their shape seems to be less constrained. The Anodonta species, inhabiting a wide spectrum of habitats and using more than twice the number of fish hosts than Unio spp., have larger glochidia with greater variation in size and shape. Our results suggest that measures of glochidial variability may also serve as an indicator of host specificity in other naiads.


Assuntos
Tamanho Corporal , Somatotipos , Unionidae/anatomia & histologia , Animais , Bivalves , Feminino , Larva , Masculino , Metamorfose Biológica , Fatores Sexuais
6.
Fish Shellfish Immunol ; 119: 533-541, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34737132

RESUMO

Metalloproteinase tissue inhibitors (TIMPs) have the activity of inhibiting matrix metalloproteinases (MMPs), which can promote cell growth, bind to the matrix, inhibit angiogenesis, and play a key role in extracellular matrix (ECM) metabolism regulation. In this study, TIMP-1, 2 from Hyriopsis cumingii (designated as HcTIMP-1, 2) were cloned and identified. Full-length cDNA of HcTIMP-1, 2 was 1160 bp and 729 bp, encoding 235 and 150 amino acid residues, respectively. The predicted molecular weight of HcTIMP-1 and 2 protein was 27.26 and 16.58 kDa, with isoelectric points of 8.89 and 8.72, respectively. HcTIMP-2 contained only one netrin (NTR) domain at the N-terminal but lacked a C-terminal domain. The mRNA of HcTIMP-1, 2 was expressed in hepatopancreas, gills, muscles, hemocytes, and mantles, which had the highest expression in hemocytes and muscles. The expression of HcTIMP-1, 2 had increased remarkably in hemocytes after bacterial challenge. After trauma, HcTIMP-1, 2 genes had the highest expression level in the first day. This indicated that HcTIMP-1 and 2 were involved in the immune response of H. cumingii. The soluble recombinant proteins HcTIMP-1, 2 were expressed efficiently in Escherichia coli BL21 (DE3) by constructing pET32a-TIMP1, 2 recombinant plasmids. The concentration of the recombinant was 0.14 and 0.31 mg/mL, respectively. The recombinant HcTIMP-1, 2 proteins were shown to inhibit human MMP2 activity and promoted the growth of NBL-7 and HUVE cells.


Assuntos
Unionidae , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Alinhamento de Sequência , Unionidae/genética
7.
Environ Toxicol Chem ; 40(12): 3392-3409, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34592004

RESUMO

The US Environmental Protection Agency's short-term freshwater effluent test methods include a fish (Pimephales promelas), a cladoceran (Ceriodaphnia dubia), and a green alga (Raphidocelis subcapitata). There is a recognized need for additional taxa to accompany the three standard species for effluent testing. An appropriate additional taxon is unionid mussels because mussels are widely distributed, live burrowed in sediment and filter particles from the water column for food, and exhibit high sensitivity to a variety of contaminants. Multiple studies were conducted to develop a relevant and robust short-term test method for mussels. We first evaluated the comparative sensitivity of two mussel species (Villosa constricta and Lampsilis siliquoidea) and two standard species (P. promelas and C. dubia) using two mock effluents prepared by mixing ammonia and five metals (cadmium, copper, nickel, lead, and zinc) or a field-collected effluent in 7-day exposures. Both mussel species were equally or more sensitive (more than two-fold) to effluents compared with the standard species. Next, we refined the mussel test method by first determining the best feeding rate of a commercial algal mixture for three age groups (1, 2, and 3 weeks old) of L. siliquoidea in a 7-day feeding experiment, and then used the derived optimal feeding rates to assess the sensitivity of the three ages of juveniles in a 7-day reference toxicant (sodium chloride [NaCl]) test. Juvenile mussels grew substantially (30%-52% length increase) when the 1- or 2-week-old mussels were fed 2 ml twice daily and the 3-week-old mussels were fed 3 ml twice daily. The 25% inhibition concentrations (IC25s) for NaCl were similar (314-520 mg Cl/L) among the three age groups, indicating that an age range of 1- to 3-week-old mussels can be used for a 7-day test. Finally, using the refined test method, we conducted an interlaboratory study among 13 laboratories to evaluate the performance of a 7-day NaCl test with L. siliquoidea. Eleven laboratories successfully completed the test, with more than 80% control survival and reliable growth data. The IC25s ranged from 296 to 1076 mg Cl/L, with a low (34%) coefficient of variation, indicating that the proposed method for L. siliquoidea has acceptable precision. Environ Toxicol Chem 2021;40:3392-3409. © 2021 SETAC.


Assuntos
Bivalves , Unionidae , Poluentes Químicos da Água , Animais , Água Doce , Testes de Toxicidade , Poluentes Químicos da Água/toxicidade
8.
Environ Toxicol Chem ; 40(12): 3410-3420, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34559934

RESUMO

Freshwater mussels are one of the most imperiled groups of animals in the world and are among the most sensitive species to a variety of chemicals. However, little is known about the sensitivity of freshwater mussels to wastewater effluents. The objectives of the present study were to (1) assess the toxicity of a permitted effluent, which entered the Deep Fork River, Oklahoma (USA), to a unionid mussel (Lampsilis siliquoidea) and to two standard test species (cladoceran Ceriodaphnia dubia; and fathead minnow Pimephales promelas) in short-term 7-day effluent tests; (2) evaluate the relative sensitivities of the three species to potassium (K), an elevated major ion in the effluent, using 7-day toxicity tests with KCl spiked into a Deep Fork River upstream reference water; (3) determine the potential influences of background water characteristics on the acute K toxicity to the mussel (96-h exposures) and cladoceran (48-h exposure) in four reconstituted waters that mimicked the hardness and ionic composition ranges of the Deep Fork River; and (4) determine the potential influence of temperature on acute K toxicity to the mussel. The effluent was found to be toxic to mussels and cladocerans, and it contained elevated concentrations of major cations and anions relative to the upstream Deep Fork River reference water. The K concentration in the effluent was 48-fold greater than in the upstream water. Compared with the standard species, the mussel was more than 4-fold more sensitive to the effluent in the 7-day effluent tests and more than 8-fold more sensitive to K in the 7-day K toxicity tests. The acute K toxicity to the mussel decreased by a factor of 2 when the water hardness was increased from soft (42 mg/L as CaCO3 ) to very hard (314 mg/L as CaCO3 ), whereas the acute K toxicity to the cladoceran remained almost the same as hardness increased from 84 to 307 mg/L as CaCO3 . Acute K toxicity to the mussel at 23 °C was similar to the toxicity at an elevated temperature of 28 °C. The overall results indicate that the two standard test species may not represent the sensitivity of the tested mussel to both the effluent and K, and the toxicity of K was influenced by the hardness in test waters, but by a limited magnitude. Environ Toxicol Chem 2021;40:3410-3420. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.


Assuntos
Bivalves , Unionidae , Poluentes Químicos da Água , Animais , Potássio , Testes de Toxicidade Crônica , Poluentes Químicos da Água/toxicidade
9.
Sci Total Environ ; 799: 149345, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34426362

RESUMO

Infaunal freshwater mussels are highly threatened and declining worldwide. One of the potential threats to mussels consists of biological invasions. We intended to investigate the habitat overlap and behavioural differences between native (Unio pictorum, Unio tumidus, Anodonta anatina, Anodonta cygnea) and invasive (Asian Sinanodonta woodiana) unionid bivalves to determine potential sources of competition. Furthermore, we investigated differences between S. woodiana from the established population in artificially heated waters and from the recent population in a natural thermal regime. We used pairwise choice tests on mud, medium, coarse and very coarse sand, mixture of medium and coarse sand, fine, medium and coarse gravel, and observed mussel locomotion and burrowing in preferred and non-preferred substrata. All species generally preferred fine-grained materials. The widest preference range was exhibited by S. woodiana (both populations), whereas A. cygnea was the most selective. The preferences of the cold-water population of S. woodiana were shifted towards coarser materials compared to conspecifics from the heated waters, and highly overlapped with the preferences of the native species. Anodonta cygnea most often moved horizontally and spent the shortest time deeply burrowed. Both Unio species were deeply burrowed for the largest amount of time and the horizontal locomotion of U. tumidus was the lowest among the test species. Sinanodonta woodiana, especially from the heated water population, exhibited relatively weak locomotion (compared to A. cygnea) and burrowing (compared to Unio spp. and A. anatina). Deep burrowing was more common on fine-grained materials. Our results suggest that the native mussels can be threatened by S. woodiana due to their overlapping habitat preferences, potentially hindering habitat separation. However, mobile native mussels may be capable of migrating and avoiding competition. Accumulating knowledge of the biology and ecology of freshwater mussels could contribute to the creation and improvement of conservation plans to protect these threatened animals.


Assuntos
Anodonta , Unio , Unionidae , Animais , Europa (Continente) , Água Doce
10.
PLoS One ; 16(8): e0256279, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34449794

RESUMO

To meet monitoring and recovery planning needs, demographic vital rates of two endangered freshwater mussels (Bivalvia: Unionidae)-the Cumberlandian Combshell (Epioblasma brevidens, Lea 1831) and Oyster Mussel (Epioblasma capsaeformis, Lea 1834), species endemic to the Tennessee and Cumberland river basins, U.S.A-were estimated and compared using census methodologies. Annual variation in population density and size, recruitment rate, mortality rate, sex ratios, and female fecundity of both species were observed from 2004-2014 at three fixed sites, spanning a 33.8 kilometer (KM) reach of the Clinch River, Hancock County, Tennessee. Mean population size of E. brevidens estimated from 11 censuses was 2,598 individuals at Swan Island (KM 277.1), 8,744 at Frost Ford (KM 291.8), and 879 at Wallen Bend (KM 309.6); collectively, these demes grew at an annual rate of 7% over the study period. Mean population size of E. capsaeformis was 7,846 individuals at Swan Island, 265,442 at Frost Ford, and 11,704 at Wallen Bend; collectively, these demes grew at an annual rate of 6%. Population size, variability in population growth, recruitment, and mortality of the shorter-lived E. capsaeformis (maximum age = 16 yrs, rarely >10 yrs) were higher than those of the longer-lived E. brevidens (maximum age = 25 yrs). Stream discharge was associated with realized per-capita population growth rate for both species when juvenile (Ages 1-3) data was included. Linear regression analysis showed that the growth rate of E. brevidens was negatively associated with median annual discharge (p = 0.0274) and that growth rate of E. capsaeformis was negatively associated with the number of days having extreme high discharge preceding a census (p = 0.0381). Fecundity of female E. brevidens averaged 34,947 (SE = 2,492) glochidia and ranged from 18,987 to 56,151, whereas fecundity of female E. capsaeformis averaged 9,558 (SE = 603) glochidia and ranged from 3,456 to 22,182. Estimated vital rates indicated that the two species are characterized by different life-history strategies, with E. brevidens exhibiting a periodic strategy (between K- and r-selected) and E. capsaeformis an opportunistic strategy (r-selected). These life history strategies are likely influenced by each species' longevity and habitat preference, in addition to the life histories and population dynamics of their primary fish hosts.


Assuntos
Monitoramento Biológico , Bivalves/fisiologia , Espécies em Perigo de Extinção , Fertilidade/fisiologia , Animais , Feminino , Peixes/fisiologia , Água Doce , Traços de História de Vida , Rios , Tennessee , Unionidae/fisiologia , Poluentes Químicos da Água
11.
Fish Shellfish Immunol ; 118: 85-93, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34438059

RESUMO

Wnt2 is a significant factor in the Wnt signaling pathway, which is associated with a variety of physiological activities, including inflammatory response, cell apoptosis, reproductive system development, and cell differentiation. Hyriopsis cumingii is the main pearl breeding mussel in China. However, the role of wnt2 in this species remains unclear. In this study, wnt2 from H. cumingii was cloned and identified. The full-length cDNA of wnt2 is 1524 bp, containing a 963 bp open reading frame (ORF), encoding 320 amino acid residues. The tissue distribution of H. cumingii indicated that wnt2 was predominantly highly expressed in the ovary and gill. And the expression profile after Aeromonas hydrophila or LPS injection indicated that wnt2 was up-regulated in gill, suggesting its role in the innate immune response. The expression of wnt2 was high at 4-month-old of early gonadal development and throughout ovarian development. In situ hybridization (ISH) showed significant hybridization signals on the gills and mature eggs of female gonads. In addition, miR-1988b-5p was found to negatively regulate wnt2 to affect the expression of key genes (frizzled-5, ctnnb1, and tcf7l) in the Wnt signaling pathway. Thus, these findings suggest a key role for wnt2 in immune regulation and gonadal development in H. cumingii.


Assuntos
Bivalves , Unionidae , Sequência de Aminoácidos , Animais , Sequência de Bases , Bivalves/genética , Clonagem Molecular , Feminino , Gônadas , Imunidade Inata/genética , Unionidae/genética
12.
Int J Biol Macromol ; 188: 800-810, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34339790

RESUMO

The biomineralization mechanism of mollusc shell has been studied for a long time, but there is a lack of understanding about the relationship between the shell formation in vitro and the signaling system in vivo. In this study, we cloned a novel shell matrix protein gene (hc-temptin), which only be characterized as a water-borne protein pheromone of molluscs in previous studies, from the freshwater mussel Hyriopsis cumingii. By bioinformatics analysis we found that temptin was a gene unique to the clade Lophotrochozoa, and it exists in all mollusc taxa except Cephalopoda. The current data supported the premise that temptin was generated in the early emergence of molluscs and that it maintained a high mutation rate to evolve relative independently. The specificity of hc-temptin expression in the mantle tissue suggests its potential to participate in biomineralization. Its sequence contained typical Ca2+ binding sites. Our experiments involving the pearl formation process, damaged shell repair process, and RNAi experiment showed that hc-temptin was a shell matrix protein that plays an important role in formation of the prismatic layer. The results of this study provided new insights about the origin of the temptin gene and its role in molluscs.


Assuntos
Biomineralização/genética , Filogenia , Proteínas/genética , Unionidae/genética , Unionidae/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA Complementar/genética , Evolução Molecular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Inativação Gênica , Nácar/metabolismo , Proteínas/química , Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
13.
Mol Phylogenet Evol ; 163: 107261, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34273504

RESUMO

Located at the junction between Europe, Africa, and Asia, with distinct evolutionary origins and varied ecological and geographical settings, together with a marked history of changes in orogeny and configuration of the main river basins, turned the Eastern Mediterranean into a region of high diversity and endemism of freshwater taxa. Freshwater mussels (Bivalvia, Unionidae) from the Western Palearctic have been widely studied in their European range, but little attention has been dedicated to these taxa in the Eastern Mediterranean region and their diversity and phylogeography are still poorly understood. The present study aims to resolve the diversity, biogeography, and evolutionary relationships of the Eastern Mediterranean freshwater mussels. To that end, we performed multiple field surveys, phylogenetic analyses, and a thorough taxonomic revaluation. We reassessed the systematics of all Unionidae species in the region, including newly collected specimens across Turkey, Israel, and Iran, combining COI + 16S + 28S and COI phylogenies with molecular species delineation methods. Phylogeographical patterns were characterized based on published molecular data, newly sequenced specimens, and species distribution data, as well as ancestral range estimations. We reveal that Unionidae species richness in the Eastern Mediterranean is over 70% higher than previously assumed, counting 19 species within two subfamilies, the Unioninae (14) and Gonideinae (5). We propose two new species, Anodonta seddonisp. nov. and Leguminaia anatolicasp. nov. Six additional taxa, Unio delicatusstat. rev., Unio eucirrusstat. rev., Unio huetistat. rev., Unio sesirmensisstat. rev., Unio terminalisstat. rev. removed from the synonymy of Unio tigridis, as well as Unio damascensisstat. rev. removed from the synonymy of Unio crassus, are re-described. The nominal taxa Unio rothi var. komarowi O. Boettger, 1880 and Unio armeniacus Kobelt, 1911 are proposed as new synonyms of Unio bruguierianus, and Anodonta cyrea Drouët, 1881 and Anodonta cilicica Kobelt & Rolle, 1895 as new synonyms of Anodonta anatina. Also, the presence of Unio tumidus in the Maritza River is confirmed. The phylogeographic patterns described here are interpreted concerning major past geological events. Conservation needs and implications are presented, together with populations and species conservation priorities.


Assuntos
Bivalves , Unio , Unionidae , Animais , Água Doce , Filogenia , Unionidae/genética
14.
Biol Open ; 10(6)2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34100539

RESUMO

Histological studies and magnetic resonance imaging were employed to analyze the kidney structure and function of the freshwater mussel, Nodularia douglasiae. The Nodularia kidney consists of proximal, intermediate and distal tubules. The epithelia of the renal tubules were composed of a single layer of cuboidal cells. The proximal and distal tubules run in opposite directions underneath the pericardial cavity. Molecular weight cut-off (MWCO) values for the kidney filtration were detected by MR tracer injections: gadolinium-diethylenetriaminepentaacetic acid (GdDTPA) at 0.55 kDa, an oligomer-based contrast agent (CH3-DTPA-Gd) at 2.2 kDa, as well as Gd-DTPA-polylysine at 10, 22, and 110 kDa. The T1w-MRI intensity and T1 relaxation rate (R1) of the pericardial cavity and renal tubules increased with tracers smaller than 10 kDa. The other tracers showed only minimal or no increase. Thus, we concluded that the MWCO of the kidney is 22 kDa, 50 times larger than that for the Mytilus living in seawater. Since the R1 values of the renal tubules were similar to those of the pericardial cavity, the kidney did not concentrate filtrated tracers. The slow decay of the magnetic resonance (MR) tracers from the renal tubules indicated a low filtration rate, suggesting that the counter-current system reabsorbs useful solutes without reabsorption of water. The higher MWCO may be beneficial to maintain the tubular oncotic pressure and allow excretion of excess water. In conclusion, a main renal function of the freshwater mussel is the excretion of water, opposite to that of the seawater mussel and vertebrates, which preserve water.


Assuntos
Rim/fisiologia , Mytilus/fisiologia , Unionidae/fisiologia , Animais , Meios de Contraste , Água Doce , Taxa de Filtração Glomerular , Imuno-Histoquímica , Rim/citologia , Rim/diagnóstico por imagem , Testes de Função Renal , Imageamento por Ressonância Magnética , Água do Mar
15.
Dev Comp Immunol ; 124: 104175, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34147569

RESUMO

Bacterial disease outbreaks in filter feeder bivalve Hyriopsis cumingii as water contamination become more frequent in the water ecosystem, especially in intensive aquaculture habitats. To characterize host-pathogen interactions between H. cumingii and bacterial infection, we investigated the effects of Stenotrophomonas maltophilia HOP3 and Aeromonas veronii GL1 on the antioxidant response, tissue invasion and transcriptome expression of H. cumingii by infectivity trials. We showed that bacterial infections resulted in tubular necrosis of the hepatopancreas and induced the acute immune response in H. cumingii. The transcriptomic study identified a total of 5957 differentially expressed genes (DEGs) after A. veronii challenge. These DEGs were implicated in 302 KEGG pathways, notably in Apoptosis, Phagosome and Lysosome. The results showed that the relative expressions of all six immune-related DEGs were effectively stimulated with A. veronii, accompanied by tissue differences. Overall, these findings will contribute to an analysis of the immune response of H. cumingii to bacterial infection at the transcriptomic level and its genomic resource for research.


Assuntos
Expressão Gênica/imunologia , Infecções por Bactérias Gram-Negativas/imunologia , Transcriptoma/imunologia , Unionidae/imunologia , Aeromonas veronii/fisiologia , Animais , Antioxidantes/metabolismo , Aquicultura , Infecções por Bactérias Gram-Negativas/genética , Infecções por Bactérias Gram-Negativas/patologia , Hepatopâncreas/imunologia , Hepatopâncreas/patologia , Interações Hospedeiro-Patógeno/imunologia , Stenotrophomonas maltophilia/fisiologia , Distribuição Tecidual , Unionidae/genética , Unionidae/microbiologia , Fatores de Virulência/imunologia
16.
Artigo em Inglês | MEDLINE | ID: mdl-34182125

RESUMO

Shell matrix proteins have important roles in the biomineralization of shells. In this study, we isolated and identified a novel shell matrix protein gene, hic7, from the mussel Hyriopsis cumingii. The cDNA of hic7 was 459 bp long, including a 240-bp open reading frame. It encoded a 79 amino acid-long protein, with amino acids 1-19 constituting the signal peptide. The resulting hic7 is rich in cysteine (16.5%). After removing the signal peptide, the molecular weight was 8.85 kDa and the theoretical isoelectric point was 6.34, indicating that hic7 is a weakly acidic shell matrix protein. Hic7 is mainly expressed in the mantle tissue of H. cumingii. In situ hybridization showed hic7 signals at the edge and dorsal region of the mantle outer fold, indicating that it is related to the formation of the prismatic and nacreous layer of the shell. RNA interference indicated that when hic7 was inhibited by 80%, the crystal morphology of the prism and nacre layers of the shell were irregular and disordered. In addition, the expression of hic7 during the early development of the pearl sac indicated that it has an important role in the transformation of calcium carbonate crystals from a disordered to an orderly deposition pattern. These results suggest that matrix protein hic7 take part in constructing the framework of crystal nucleation and regulating the calcium carbonate crystal morphology of the nacreous and prismatic layers of shells and pearls.


Assuntos
Exoesqueleto/crescimento & desenvolvimento , Proteínas da Matriz Extracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Nácar/biossíntese , Unionidae/crescimento & desenvolvimento , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/isolamento & purificação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/isolamento & purificação , Unionidae/genética , Unionidae/metabolismo
17.
Sci Rep ; 11(1): 10752, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34031525

RESUMO

Detailed information on species delineation and population genetic structure is a prerequisite for designing effective restoration and conservation strategies for imperiled organisms. Phylogenomic and population genomic analyses based on genome-wide double digest restriction-site associated DNA sequencing (ddRAD-Seq) data has identified three allopatric lineages in the North American freshwater mussel genus Cyprogenia. Cyprogenia stegaria is restricted to the Eastern Highlands and displays little genetic structuring within this region. However, two allopatric lineages of C. aberti in the Ozark and Ouachita highlands exhibit substantial levels (mean uncorrected FST = 0.368) of genetic differentiation and each warrants recognition as a distinct evolutionary lineage. Lineages of Cyprogenia in the Ouachita and Ozark highlands are further subdivided reflecting structuring at the level of river systems. Species tree inference and species delimitation in a Bayesian framework using single nucleotide polymorphisms (SNP) data supported results from phylogenetic analyses, and supports three species of Cyprogenia over the currently recognized two species. A comparison of SNPs generated from both destructively and non-destructively collected samples revealed no significant difference in the SNP error rate, quality and amount of ddRAD sequence reads, indicating that nondestructive or trace samples can be effectively utilized to generate SNP data for organisms for which destructive sampling is not permitted.


Assuntos
Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA/veterinária , Unionidae/classificação , Animais , Teorema de Bayes , DNA Mitocondrial/genética , América do Norte , Filogenia , Unionidae/genética
18.
Dev Comp Immunol ; 122: 104136, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34004268

RESUMO

Nitric oxide synthase (NOS) is a critical enzyme that catalyzes nitric oxide biosynthesis and orchestrates various immunological responses mediated by nitric oxide (NO) in host animals. In this study, the NOS gene was identified in the triangle shell mussel (Hyriopsis cumingii) (HcNOS). HcNOS was highly conserved in the characteristic gene structures of NOS. Phylogenetic analysis suggested that HcNOS was a typical invertebrate NOS. Further gene expression analysis, NOS activity assays and nitric oxide content measurements demonstrated the inducibility of HcNOS in responses to lipopolysaccharide (LPS) challenge and during tissue transplantation. Of note, mantle grafting induced a prolonged HcNOS/NO response, suggesting that through the HcNOS/NO system, multiple immunomodulators may play decisive roles in tissue grafting in triangle shell mussels. Thus, HcNOS appears to be a crucial player in responding to both bacterial infection and tissue transplantation.


Assuntos
Exoesqueleto/transplante , Óxido Nítrico Sintase/genética , Óxido Nítrico/biossíntese , Unionidae/genética , Unionidae/imunologia , Animais , Bactérias/imunologia , Infecções Bacterianas/imunologia , Imunidade Inata/genética , Imunidade Inata/imunologia , Imunomodulação/genética , Lipopolissacarídeos/imunologia , Filogenia , Transplante de Tecidos/métodos
19.
Anim Reprod Sci ; 230: 106768, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34051647

RESUMO

Freshwater unionid mussel diversity is decreasing because of species extirpation or extinction. While little can be done to recover lost species, there is an opportunity to develop techniques to save other species. This can be facilitated through gene banking and assisted reproduction. Unfortunately, limited information is available on mussel reproduction, especially relating to sperm quality. Objectives, therefore, were to quantify seasonal changes in sperm concentration and morphology for two unionid mussels, Ligumia subrostrata and Lampsilisstraminea, measure intraspecific heterogeneity for sperm morphometry, and develop an efficient method to quantify sperm concentration using a microspectrophotometer. There were no differences in sperm concentration when cells were extracted from the center or at a half centimeter on either side of the visceral mass, during the spawning season. There was a seasonal change in sperm concentration, such that concentration for L. subrostrata ranged from 1.1 × 109 to 19.60 × 109 cells/mL with there being the largest counts between 26 September to 7 November. L. straminea sperm concentration was greatest (20.0 × 109 cells/mL) on 13 September and subsequently decreased. Sperm were uniflagellated and SEM results for L. subrostrata and L. straminea showed mean head length and width (mid-spawning) were 3.38 ± 0.04 µm and 1.61 ± 0.01 µm and 3.37 ± 0.04 µm and 1.61 ± 0.01 µm, respectively. There were close (R2 ≥ 0.85) quadratic associations between hemocytometer counts and absorbance (300, 600, 700 nm). These results provide baseline information to further investigate sperm quality, fertilizing capacity, and cryopreservation for freshwater mussels.


Assuntos
Estações do Ano , Espermatozoides/fisiologia , Unionidae/genética , Unionidae/fisiologia , Animais , Masculino , Microespectrofotometria , Especificidade da Espécie , Unionidae/classificação
20.
Sci Rep ; 11(1): 8244, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33972560

RESUMO

The Mekong and Chao Phraya rivers harbor a species-rich freshwater mussel assemblage containing a large radiation of the Pseudodontini species. Members of the genera Bineurus Simpson 1900 and Thaiconcha Bolotov et al., 2020 primarily inhabit small and medium-sized tributaries of these rivers. Here, we present an integrative taxonomic review of these genus-level clades. We show that Bineurus contains four species: B. mouhotii (Lea, 1863), B. exilis (Morelet, 1866) stat. rev., B. anodontinum (Rochebrune, 1882) stat. rev., and B. loeiensis sp. nov. In its turn, Thaiconcha comprises three species: T. callifera (Martens, 1860), T. munelliptica sp. nov., and T. thaiensis sp. nov. Two species, Pseudodon ovalis Morlet, 1889 and P. thomsoni Morlet, 1884, are considered here as questionable taxa. These findings further highlight that Southeast Asia represents a significant evolutionary hotspot of freshwater mussels, which requires further international collaborative research and conservation efforts.


Assuntos
Unionidae/classificação , Animais , Ásia Sudeste , Evolução Biológica , Água Doce , Filogenia , Filogeografia
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