Natural variation in the cytochrome c oxidase subunit 5B OsCOX5B regulates seed vigor by altering energy production in rice

Seed vigor is a crucial trait for the direct seeding of rice.Here we examined the genetic regulation of seed vigor traits in rice,including germination index(GI)and germination potential(GP),using a genome-wide association study approach.One major quantitative trait locus,qGI6/qGP6,was identified simultaneously for both GI and GP.The candidate gene encoding the cytochrome c oxidase subunit 5B(OsCOX5B)was validated for qGI6/qGP6.The disruption of OsCOX5B caused the vigor traits to be significantly lower in Oscox5b mutants than in the japonica Nipponbare wild type(WT).Gene co-expression analysis revealed that OsCOX5B influences seed vigor mainly by modulating the tricarboxylic acid cycle process.The glucose levels were significantly higher while the pyruvic acid and adenosine triphosphate levels were significantly lower in Oscox5b mutants than in WT during seed germination.The elite haplotype of OsCOX5B facilitates seed vigor by increasing its expression during seed germination.Thus,we propose that OsCOX5B is a potential target for the breeding of rice varieties with enhanced seed vigor for direct seeding.

Hippocampal mitochondrial cytochrome C oxidase activity and gene expression in a rat model of chronic cerebral ischemia

The present study established a rat model of chronic cerebral ischemia using bilateral common carotid artery permanent ligation to analyze cytochrome C oxidase activity and mRNA expression in hippocampal mitochondria. Results showed significantly decreased cytochrome C oxidase activity and cytochrome C oxidase II mRNA expression with prolonged ischemia time. Further analysis revealed five mitochondrial cytochrome C oxidase II gene mutations, two newly generated mutations, and four absent mutational sites at 1 month after cerebral ischemia, as well as three mitochondrial cytochrome C oxidase III gene mutations, including two newly generating mutations, and one disappeared mutational site at 1 month after cerebral ischemia. Results demonstrated that decreased cytochrome C oxidase gene expression and mutations, as well as decreased cytochrome C oxidase activity, resulting in energy dysmetabolism, which has been shown to be involved in the DatholoQical Process of ischemic brain iniurv.

Regulation of cytochrome c oxidase contributes to health and optimal life

The generation of cellular energy in the form of ATP occurs mainly in mitochondria by oxidative phosphorylation.Cytochrome c oxidase(CytOx),the oxygen accepting and rate-limiting step of the respiratory chain,regulates the supply of variable ATP demands in cells by“allosteric ATP-inhibition of CytOx.”This mechanism is based on inhibition of oxygen uptake of CytOx at high ATP/ADP ratios and low ferrocytochrome c concentrations in the mitochondrial matrix via cooperative interaction of the two substrate binding sites in dimeric CytOx.The mechanism keeps mitochondrial membrane potentialΔΨm and reactive oxygen species(ROS)formation at low healthy values.Stress signals increase cytosolic calcium leading to Ca^2+-dependent dephosphorylation of CytOx subunit I at the cytosolic side accompanied by switching off the allosteric ATPinhibition and monomerization of CytOx.This is followed by increase ofΔΨm and formation of ROS.A hypothesis is presented suggesting a dynamic change of binding of NDUFA4,originally identified as a subunit of complex I,between monomeric CytOx(active state with highΔΨm,high ROS and low efficiency)and complex I(resting state with lowΔΨm,low ROS and high efficiency).

Enzymatic Activity of Escherichia Coil Lactate Dehydrogenase and Cytochrome c Oxidase

The catalytic activity of two common bacterial enzymes, lactate dehydrogenase （LDH） and cytochrome c oxidase （COX） from Escherichia coli was examined following bacterial exposure to microwave （MW） radiation under well-defined experimental conditions. The experiments were conducted in a specialized microwave processing apparatus, with an exposure frequency of 18 GHz, and a temperature profile that was restricted to below 40℃ to avoid thermal degradation of the bacteria. The absorbed power was calculated to be 1,500 kW/m3 and the electric field was determined to be 300 Wm. Both values were theoretically confirmed using Computer Simulation Technology （CST） Microwave Studio 3D Electromagnetic Stimulation Software. Results showed that the activity of both enzymes was increased following MW radiation compared to negative controls and thermally treated samples subjected to similar temperature profiles. It is suggested that the increase in COX and LDH enzyme activity could not be explained by conventional heating alone, but was rather a result of micro-thermal effects that incorporated ＇undetectable＇ thermal mechanisms.

Epiphytic zooplankton community profiles in a typical urban wetland as revealed by DNA metabarcoding

Zooplankton,a crucial component of urban wetland,are one of the effective bioindicators for monitoring the feeding stocks of organisms at higher trophic levels and assessing the ecological quality of ecosystems.However,information about the characteristics of epiphytic zooplankton community structure resulted from traditional methods is limited and hindered by the large amount of detritus and sludge attached to the macrophytes.We investigated the epiphytic zooplankton communities associated with macrophytes(Vallisneria,Nymphaea,and Thalia dealbata)in a subtropical wetland using as DNA markers of the 18 S rRNA gene and the mitochondrial cytochrome c oxidase subunit I(COI)gene.A total of 241 OTUs of zooplankton were obtained from COI amplicons,including 194 OTUs of Rotifera,22 of Cladocera,and 25 of Copepoda,while only 62 OTUs of zooplankton were obtained from 18 S rDNA amplicons including 34 OTUs of Rotifera and 28 of Copepoda.The zooplankton communities associated with the three macrophytes were similar,but they differed significantly from those in the open waters.However,there were no significant temporal differences among the zooplankton communities.Epiphytic zooplankton communities were dominated by littoral zooplankton such as Testudinella,Lecane,and Philodina.Microzooplankton,especially littoral species,utilize macrophytes as food sources and as refuges against predation.This further led to an increase inαandβdiversity of zooplankton communities in urban wetlands.Our result suggests that the joint use of multiple molecular markers could improve the taxonomic resolution and generate a comprehensive biodiversity profile of zooplankton.

Construction of Cox7a2 fluorescent vector and its effect on cytochrome C oxidase activity in mouse Sertoli cell line TM4

Objective To construct Cox7a2 fluorescent vector and study its effect on cytochrome C oxidase ( COX) activity in mouse Sertoli cell line TM4. Methods The coding region of CoxTa2 was amplified from mouse Sertoli cell line TM4 by RT-PCR. PCR product was

Resveratrol engages selective apoptotic signals in gastric adenocarcinoma cells

AIM： To investigate the intracellular apoptotic signals engaged by resveratrol in three gastric adenocarcinoma cancer cell lines, two of which （AGS and SNU-1） express p53 and one （KATO-M） with deleted p53. METHODS： Nuclear fragmentation was used to quantitate apoptotic cells; caspase activity was determined by photometric detection of cleaved substrates; formation of oxidized cytochrome C was used to measure cytochrome C activity, and Western blot analysis was used to determine protein expression, RESULTS： Gastric cancer cells, irrespective of their p53 status, responded to resveratrol with fragmentation of DNA and cleavage of nuclear lamins A and B and PARP. Resveratrol, however, has no effect on mitochondria-associated apoptotic proteins Bcl-2, Bcl- xl, Bax, Bid or Smac/Diablo, and did not promote sub-cellular redistribution of cytochrome C, indicating that resveratrol-induced apoptosis of gastric carcinoma cells does not require breakdown of mitochondrial membrane integrity. Resveratrol up-regulated p53 protein in SNU-1 and AGS cells but there was a difference in response of intracellular apoptotic signals between these cell lines. SNU-1 cells responded to resveratrol treatment with down-regulation of survivin, whereas in AGS and KATO- 111 cells resveratrol stimulated caspase 3 and cytochrome C oxidase activities. CONCLUSION： These findings indicate that even within a specific cancer the intracellular apoptotic signals engaged by resveratrol are cell type dependent and suggest that such differences may be related to differentiation or lack of differentiation of these cells.

Altered expression of mitochondrial related genes in the native Tibetan placents by mitochondrial cDNA array analysis

Objective： To explore the mechanism of native Tibetan fetuses adaptation to hypoxia, we tried to find the different expression genes about mitochondrial function in the native Tibetan placents. Methods： In this study, the placents of native Tibetan and the high-altitude Hart （ha-Hart） were collected. After the total RNA extraction, the finally synthesized cDNAs were hybridized to mitochondrial array to find the altered expression genes between them. Then, the cytochrome c oxidase 17 （Coxl7）, dynactin 2 （DCTN2, also known as p50）, and vascular endothelial growth factor receptor （VEGFR, also known as KDR） were chosen from the altered expression genes to further verify the array results using the SYBR Green real-time PCR. Because the altered expression genes （such as Cybb and Cox 17） in the array results related to the activities of COXI and COXIV, the placental mitochondria activities of COXI and COXIV were measured to find their changes in the hypoxia. Results： By a standard of≥1.5 or ≤0.67, there were 24 different expressed genes between the native Tibetan and the ha-Han placents, including 3 up-regulated genes and 21 down-regulated genes. These genes were related to energy metabolism, signal transduction, cell proliferation, electron transport, cell adhesion, nucleotide-excision repair. The array results of Cox17, DCTN2 and KDR were further verified by the real-time RT-PCR. Through the mitochondria respiration measurements, the activity of COXI in the native Tibetan placents were higher than that of ha-Han, there was no difference in COXIV activity between them. Conclusion： The altered mitochondrial related genes in the native Tibetan placents may have a role in the high altitude adaptation for fetuses through changing the activity of mitochondrial COX.

Mitochondrial protective and anti-apoptotic effects of Rhodiola crenulata extract on hippocampal neurons in a rat model of Alzheimer's disease

In our previous study, we found that the edible alcohol extract of the root of the medicinal plant Rhodiola crenulata（RCE） improved spatial cognition in a rat model of Alzheimer＇s disease. Another study from our laboratory showed that RCE enhanced neural cell proliferation in the dentate gyrus of the hippocampus and prevented damage to hippocampal neurons in a rat model of chronic stress-induced depression. However, the mechanisms underlying the neuroprotective effects of RCE are unclear. In the present study, we investigated the anti-apoptotic effect of RCE and its neuroprotective mechanism of action in a rat model of Alzheimer＇s disease established by intracerebroventricular injection of streptozotocin. The rats were pre-administered RCE at doses of 1.5, 3.0 or 6.0 g/kg for 21 days before model establishment. ATP and cytochrome c oxidase levels were significantly decreased in rats with Alzheimer＇s disease. Furthermore, neuronal injury was obvious in the hippocampus, with the presence of a large number of apoptotic neurons. In comparison, in rats given RCE pretreatment, ATP and cytochrome c oxidase levels were markedly increased, the number of apoptotic neurons was reduced, and mitochondrial injury was mitigated. The 3.0 g/kg dose of RCE had the optimal effect. These findings suggest that pretreatment with RCE prevents mitochondrial dysfunction and protects hippocampal neurons from apoptosis in rats with Alzheimer＇s disease.

Seasonal phenotypic flexibility in body mass,basal thermogenesis,and tissue oxidative capacity in the male Silky Starling(Sturnus sericeus)

Background: Acclimatization to winter conditions is an essential prerequisite for the survival of small birds in the northern temperate zone.Changes in photoperiod,ambient temperature and food availability trigger seasonal physiological and behavioral acclimatization in many passerines.Seasonal trends in metabolic parameters are well known in avian populations from temperate environments;however,the physiological and biochemical mechanisms underlying these trends are incompletely understood.In this study,we used an integrative approach to measure variation in the thermogenic properties of the male Silky Starling(Sturnus sericeus) at different levels or organization,from the whole organism to the biochemical.We measured body mass(Mb),basal metabolic rate(BMR),energy budget,the mass of selected internal organs,state 4 respiration and cytochrome c oxidase(COX) activity in the heart,liver and muscle.Methods: Oxygen consumption was measured using an open-circuit respirometry system.The energy intake of the birds were then determined using an oxygen bomb calorimeter.Mitochondrial state 4 respiration and COX activity in heart,liver and pectoral muscle were measured with a Clark electrode.Results: The results suggest that acclimatization to winter conditions caused significant change in each of the measured variables,specifically,increases in Mb,organ mass,BMR,energy intake and cellular enzyme activity.Furthermore,BMR was positively correlated with body mass,energy intake,the mass of selected internal organs,state 4 respiration in the heart,liver and muscle,and COX activity in the heart and muscle.Conclusions: These results suggest that the male Silky Starling's enhanced basal thermogenesis under winter conditions is achieved by making a suite of adjustments from the whole organism to the biochemical level,and provide further evidence to support the notion that small birds have high phenotypic plasticity with respect to seasonal changes.

Genetic diversity and population structure of Eleutheronema rhadinum in the East and South China Seas revealed in mitochondrial COI sequences

Eleutheronema rhadinum is a potential commercial fisheries species and is subject to intense exploitation in China. Knowledge on the population structure of E. rhadinum in Chinese coastal waters, which is important for sustainable exploitation and proper resource management, is lacking. In the present study, the genetic diversity and population structure of E. rhadinum were evaluated using a 564-base pair fragment of the mitochondrial cytochrome c oxidase subunit I （COl） gene. A total of 76 specimens were collected from three localities around the East （Qidong and Zhoushan） and South China Seas （Zhuhai）. Among these individuals, nine polymorphic sites were detected and 1 l distinct haplotypes were defined. High levels ofhaplotype diversity （h=0.759i0.035） and low levels of nucleotide diversity （re=0.001 98i0.003 26） were observed in these populations, Hierarchical analysis of molecular variance （AMOVA） indicated that 96.72% of the genetic variation occurred within the populations, whereas 3.28% occurred among populations. No significant genealogical branches or clusters were recognized on the neighbor-joining tree. Intra-group variation among populations was significant （~0~t=0.032 85, P〈0.01）. These results suggest that E. rhadinum populations in the East and South China Seas have developed divergent genetic structures. Tests of neutral evolution and mismatch distribution suggest that E. rhadinum may have experienced a population expansion. The present study provides basic information for the conservation and sustainable exploitation of this species.

First record of the little fire ant,Wasmannia auropunctata(Hymenoptera:Formicidae),in Chinese mainland

In January 2022,we received ant specimens collected from three field colonies from Shantou City,Guangdong Province,China.They were identified as the little fire ant,Wasmannia auropunctata,through morphological and molecular analyses.Wasmannia auropunctata is listed as one of the 100 most dangerous invasive species by the International Union for Conservation of Nature(IUCN)and has spread from its native range in South America to every continent except Antarctica.DNA analysis of mitochondrial cytochrome c oxidase subunit I(COI)in nine specimens of W.auropunctata found that they had a close genetic relationship with specimens from Argentina.This study represents the first formal record of the establishment of W.auropunctata outdoor in Chinese mainland.However,the invasion stage and occurrence degree of W.auropunctata in China are not clear to date.The implementation of quarantine measures,investigation of the occurrence and distribution,and development of monitoring and control strategies are needed to actively respond to the threat posed by this highly invasive ant.

Identification of differentially expressed genes of primary spermatocyte against round spermatid isolated from human testis using the laser capture microdissection technique

The method of laser capture microdissection (LCM) combined with suppressive subtractive hybridization (SSH) was developed to isolate specific germ cells from human testis sections and to identify the genes expressed during differentiation and development. In the present study, over 10,000 primary spermatocytes and round spermatid cells were successfully isolated by LCM. Using the cDNAs from primary spermatocytes and round spermatids, SSH cDNAs library of primary spermatocyte-specific was constructed. The average insert size of the cDNA isolated from 75 randomly picked white clones was 500 bp, ranging from 250 bp to 1.7 kb. Using the dot-blot method, a total of 421 clones were examined, resulting in the identification of 390 positive clones emitting strong signals. Partial sequence of cDNAs prepared from each clone was determined with an overall success rate of 84.4%. Genes encoding cytochrome c oxidase II and the rescue factor-humanin were most frequently expressed in primary spermatocytes, suggesting their roles involved in meiosis.

The role of temperature as a driver of metabolic flexibility in the Red-billed Leiothrix(Leiothrix lutea)

Background:The thermoregulatory ability of animals is strongly influenced by the temperature of their environment.Acclimation to cold requires a range of physiological and morphological adjustments.In this study,we tested the hypothesis that a small passerine,the Red-billed Leiothrix(Leiothrix lutea),can maintain homeothermy in cold conditions by adjusting the physiology and biochemistry of its tissue and organs and return to its former physiological and biochemical state when moved to a warm temperature.Methods:Phenotypic variation in thermogenic activity of the Red-billed Leiothrixs(Leiothrix lutea)was investigated under warm(35℃),normal(25℃)or cold(15℃)ambient temperature conditions.Oxygen consumption was measured using an open-circuit respirometry system.Mitochondrial state-4 respiration and cytochrome-c oxidase(COX)activity in liver,kidney heart and pectoral muscle were measured with a Clark electrode.Results:Birds acclimated to an ambient temperature of 15℃ for 4 weeks significantly increased their basal metabolic rate(BMR)compared to a control group kept at 25℃.Birds acclimated to 35℃ decreased their BMR,gross energy intake(GEI)and digestible energy intake(DEI).Furthermore,birds acclimated to 15℃ increased state-4 respiration in their pectoral muscles and cytochrome-c oxidase(COX)activity in their liver and pectoral muscle,compared to the 25℃ control group.Birds acclimated to 35℃ also displayed lower state-4 respiration and COX activity in the liver,heart and pectoral muscles,compared to those kept at 25℃.There was a positive correlation between BMR and state-4 respiration,and between BMR and COX activity,in all of the above organs except the liver and heart.Conclusions:Our study illustrates that the morphological,physiological,and enzymatic changes are associated with temperature acclimation in the Red-billed Leiothrix,and supports the notion that the primary means by which small birds meet the energetic challenges of cold conditions is through metabolic adjustments.

Effects of sustained cold and heat stress on energy intake, growth and mitochondrial function of broiler chickens

To study the correlation of broiler chickens with energy intake, growth and mitochondrial function which exposed to sustained cold and heat stress and to find out the comfortable temperature, 288 broiler chickens（21-day with（748±26） g, 144 males and 144 females） were divided randomly into six temperature-controlled chambers. Each chamber contained six cages including eight AA broilers per cage, each cage as a repeat. After acclimation for one week（temperature, 21℃; relative humidity, 60%）, the temperature of each chamber was adjusted（finished within 1 h） respectively to 10, 14, 18, 22, 26, or 30℃（RH, 60%） for a 14-day experimental period. After treatment, gross energy intake（GEI）, metabolizable energy intake（MEI）, the ratio of MEI/BW, metabolizability, average daily gain（ADG）, the concentration of liver mitochondria protein and cytochrome c oxidase（CCO） were measured respectively. Our results confirmed that when the temperature over 26℃ for 14 days, GEI, MEI and CCO activities were decreased significantly（P〈0.05）, but the concentration of liver mitochondria protein was increased and metabolizability of broilers was not influenced（P〉0.05）. Compared with treatment for 14 days, the ratio of MEI/body weight（BW） were also decreased when the temperature over 26℃ after temperature stress for 7 days（P〈0.05）, meanwhile mitochondrial protein concentration was increased at 10℃ and CCO activity was not affected（P〉0.05）. Additionally at 22℃, the ADG reached the maximal value. When kept in uncomfortable temperatures for a long time, the ADG and CCO activities of broiler were reduced, which was accompanied by mitochondrial hyperplasia. In summary, our study focused on the performance of broilers during sustained cold and heat environmental temperatures ranging from 10 to 30℃. From the point of view of energy utilization, moreover, 22 to 26℃ is comfortable for 28–42 day s broilers. And these could provide the theoretical basis on the high efficient production.

Morphological and molecular characterization of the rice root-knot nematode, Meloidogyne graminicola, Golden and Birchfeild, 1965 occurring in Zhejiang, China

The rice root-knot nematode Meloidogyne graminicola is a severe pest of rice. In China, it was first reported from Hainan Province, and later from several other provinces. In the present study, a rice root-knot nematode population found from the rice cultivation areas of Zhejiang Province, China is characterized via molecular analysis using internal transcribed spacer(ITS) and cytochrome c oxidase subunit Ⅱ(coxⅡ)-16 S rRNA genes and scanning electron microscopy(SEM) observations of males and the second-stage juveniles. Morphometric data and molecular sequence comparisons for all M. graminicola populations occurring in China are also provided. The overall morphology of M. graminicola found in Zhejiang match well with the original description, though males have a slightly longer body and stylet, and a shorter tail, while the second-stage juvenile is also slightly longer than in the original description. This is the first report of M. graminicola from Zhejiang. Phylogenetic studies based on coxⅡ suggest that all the Chinese populations belong to Type B. This study expands knowledge of the increasing distribution and phylogenetic relationships of M. graminicola that occur in China.

DNA barcode assessment of Ceramiales(Rhodophyta) in the intertidal zone of the northwestern Yellow Sea

A total of 142 specimens of Ceramiales （Rhodophyta） were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species, 14 genera, and four families. Cluster analyses show that the specimens had a high diversity for the three DNA markers, namely, partial large subunit rRNA gene （LSU）, universal plastid amplicon （UPA）, and partial mitochondrial cytochrome c oxidase subunit I gene （COl）. No intraspecific divergence was found in our collection for these markers, except for a 1-3 bp divergence in the COI of Ceramium kondoi, Syrnphyocladia latiuscula, and Neosiphoniajaponica. Because short DNA markers were used, the phylogenetic relationships of higher taxonomic levels were hard to evaluate with poor branch support. More than half species of our collection failed to find their matched sequences owing to shortage information of DNA barcodes for macroalgae in GenBank or BOLD （Barcode of Life Data） Systems. Three specimens were presumed as Heterosiphonia crispella by cluster analyses on DNA barcodes assisted by morphological identification, which was the first record in the investigated area, implying that it might he a cryptic or invasive species in the coastal area of northwestern Yellow Sea. In the neighbor-joining trees of all three DNA markers, Heterosiphonia japonica converged with Dasya spp. and was distant from the other Heterosiphonia spp., implying that H.japonica had affinities to the genus Dasya. The LSU and UPA markers amplified and sequenced easier than the COI marker across the Ceramiales species, but the COI had a higher ability to discriminate between species.

DNA barcoding of fishes from Zhoushan coastal waters using mitochondrial COI and 12S rRNA genes

Accurate species identification is a key component of biodiversity research.DNA barcoding is an effective molecular method used for fish species identification.We aimed to study the DNA barcoding of fish in Zhoushan coastal waters,explore the differences and applicability of two gene fragments(12S rRNA and COI)of DNA barcoding in fish species identification,and established a comprehensive fish barcoding reference database.Two hundred and eighty-seven captured fish samples from Zhoushan coastal waters were identified using morphological characteristics and DNA barcoding.A total of 26412S rRNA sequences(belonging to eight orders,31 families,55 genera,and 66 species)and 188 COI sequences(belonging to seven orders,30 families,48 genera,and 58 species)were obtained.The lengths of the 12S rRNA sequences ranged from 165 to 178 bp,and the guanine-cytosine(GC)content was 45.37%.The average 12S rRNA interspecific and intraspecific genetic distances(K2P)were 0.10%and 26.66%,respectively.The length of the COI sequence ranged 574–655 bp,and the content of GC was 45.97%.The average 12S rRNA interspecific and intraspecific genetic distances(K2P)were 0.16%and 27.45%,respectively.The minimum interspecific genetic distances of 12S rRNA and COI(1.23%and 1.86%)were both greater than their maximum intraspecific genetic distances(2.42%and 8.66%).Three molecular analyses(NJ tree,ABGD,and GMYC)were performed to accurately identify and delineate species.Clustering errors occurred when the 12S rRNA sequences were delimited using the NJ tree method,and the delimitation results of ABGD and GMYC are consistent with the final species identification results.Our results demonstrate that DNA barcoding based on 12S rRNA and COI can be used as an effective tool for fish species identification,and 12S rRNA has good application prospects in the environmental DNA(eDNA)metabarcoding of marine fish.

The complete mitochondrial genome of Triuncina daii(Lepidoptera:Bombycidae) and its phylogenetic implications

The bombycid moth, Triuncina daii Xing Wang ＆ Zolotuhin, 2015, plays an important role for analyzing the phylogenetic relationships of the family Bombycidae （Lepidoptera： Bombycoidea）. Here we first describe the complete mitochondrial genome （mitogenome） of T. daii, which includes thirteen protein-coding genes （PCGs）, twenty-two transfer RNA genes, two ribosomal RNA genes and an A＋T-rich region, and we find the mitogenome is 15,482 bp in length （GenBank no. KY091643）. The genes order and orientation in the T. daii mitogenome are similar to other sequenced lepidopteran species. Except for cox1, all of the PCGs started with ATN. Twelve PCGs stopped at TAA except for cox1 which stops at a single T. Thirteen PCGs of available species are used to demonstrate the inner phylogenetic relationships of Bombycoidea. The bombycid species form a monophyletic clade with a bootstrap value of 100% and a posterior probability of 1.00.

Benthodytes tetrapapillata sp.nov.,a new elasipodid sea cucumber(Elasipodida:Psychropotidae)from a seamount in the Western Pacific Ocean

Benthodytes tetrapapillata sp.nov.was collected from a seamount located on the Caroline Ridge at a depth of 2289 m,during the cruise of R/V Kexue in June 2019.We provided detailed descriptions of external and deposits morphology.The phylogenetic analyses based on cytochrome c oxidase I(COI)and a concatenated dataset of 16S and COI genes showed that the new species belonged to Benthodytes that is not monophyletic.Both details of morphological comparisons and molecular analyses confirmed that Benthodytes tetrapapillata sp.nov.is a new psychropotid species.A state of main morphological characters in valid species of Benthodytes is also provided in this study.