Effects of poly-ether B on proteome and phosphoproteome expression in biofouling Balanus amphitrite cyprids

KAUST Repository

Dash, Swagatika

2012-04-01

Biofouling is ubiquitous in marine environments, and the barnacle Balanus amphitrite is one of the most recalcitrant and aggressive biofoulers in tropical waters. Several natural antifoulants that were claimed to be non-toxic have been isolated in recent years, although the mechanism by which they inhibit fouling is yet to be investigated. Poly-ether B has shown promise in the non-toxic inhibition of larval barnacle attachment. Hence, in this study, multiplex two-dimensional electrophoresis (2-DE) was applied in conjunction with mass spectrometry to investigate the effects of poly-ether B on barnacle larvae at the molecular level. The cyprid proteome response to poly-ether B treatment was analyzed at the total proteome and phosphoproteome levels, with 65 protein and 19 phosphoprotein spots found to be up- or down-regulated. The proteins were found to be related to energy-metabolism, oxidative stress, and molecular chaperones, thus indicating that poly-ether B may interfere with the redox-regulatory mechanisms governing the settlement of barnacle larvae. The results of this study demonstrate the usefulness of the proteomic technique in revealing the working mechanisms of antifouling compounds. © 2012 Copyright Taylor and Francis Group, LLC.

Long-term effects of the water-accomodated fraction (WAF) of diesel oil on rocky shore populations maintained in experimental mesocosms

Energy Technology Data Exchange (ETDEWEB)

Bokn, T.L. [Norwegian Inst. for Water Research, Oslo (Norway); Moy, F.E. [Norwegian Inst. for Water Research, Oslo (Norway); Murray, S.N. [California State Univ., Fullerton, CA (United States). Dept. of Biological Science

1993-12-31

The long-term effects of continuous doses (average hydrocarbon concentration =129.4 {mu}g L{sup -1} and 30.1 {mu}g L{sup -1}) of the water-accommodated fraction (WAF) of diesel oil on 15 rocky littoral populations were determined at three tidal levels in experimental mesocosms over two years. At each tidal level, most species exhibited similar abundance changes in both oil-contaminated and control (average background hydrocarbon concentration = 5.6 {mu}g L{sup -1}) mesocosms. Significant changes in species abundances attributable to oil (WAF) were demonstrated for only two of ten seaweeds and three of five invertebrates. Compared with the other mesocosms, significantly greater reductions in upper-level cover were recorded in the basin receiving the highest oil dosage for the seaweeds Phymatolithon lenormandii and Fucus evanescents together with lower recruitment of the barnacle Semibalanus balanoides. The mussel Mytilus edulis was storngly affected by the oil treatments and essentially disappeared from both oil-contaminated mesocosms. Numbers of the starfish Asterias rubens also fell to zero at the lowest tidal level in the basin receiving the highest oil dosage. There were no demonstrable differences in the abundance patterns of the gastropod Littorina littorea, the crab Carcinus maenus, and a total of eight brown (Ascophyllum nodosum, Fucus serratus, F. vesiculosus, Laminaria digitata), red (Chondrus crispus), and green (Cladophora rupestris, Enteromorpha spp., Ulva lactuca) seaweeds in the oil-contaminated compared with the control mesocosms. (orig.)

Long-term effects of the water-accomodated fraction (WAF) of diesel oil on rocky shore populations maintained in experimental mesocosms

International Nuclear Information System (INIS)

Bokn, T.L.; Moy, F.E.; Murray, S.N.

1993-01-01

The long-term effects of continuous doses (average hydrocarbon concentration =129.4 μg L -1 and 30.1 μg L -1 ) of the water-accommodated fraction (WAF) of diesel oil on 15 rocky littoral populations were determined at three tidal levels in experimental mesocosms over two years. At each tidal level, most species exhibited similar abundance changes in both oil-contaminated and control (average background hydrocarbon concentration = 5.6 μg L -1 ) mesocosms. Significant changes in species abundances attributable to oil (WAF) were demonstrated for only two of ten seaweeds and three of five invertebrates. Compared with the other mesocosms, significantly greater reductions in upper-level cover were recorded in the basin receiving the highest oil dosage for the seaweeds Phymatolithon lenormandii and Fucus evanescents together with lower recruitment of the barnacle Semibalanus balanoides. The mussel Mytilus edulis was storngly affected by the oil treatments and essentially disappeared from both oil-contaminated mesocosms. Numbers of the starfish Asterias rubens also fell to zero at the lowest tidal level in the basin receiving the highest oil dosage. There were no demonstrable differences in the abundance patterns of the gastropod Littorina littorea, the crab Carcinus maenus, and a total of eight brown (Ascophyllum nodosum, Fucus serratus, F. vesiculosus, Laminaria digitata), red (Chondrus crispus), and green (Cladophora rupestris, Enteromorpha spp., Ulva lactuca) seaweeds in the oil-contaminated compared with the control mesocosms. (orig.)

The relative magnitude of the effects of biological and physical settlement cues for cypris larvae of the acorn barnacle, Semibalanus balanoides L.

NARCIS (Netherlands)

Prendergast, G.S.; Zurn, C.M.; Bers, A.V.; Head, R.M.; Hansson, L.J.; Thomason, J.C.

2009-01-01

Barnacle cypris larvae respond to many cues when selecting a settlement site. The settlement of over a million larvae on tiles of different textures, orientations and densities of incumbent settlers was measured on the rocky intertidal at Great Cumbrae, Scotland. Half of the tiles were replaced

Toward an understanding of the molecular mechanisms of barnacle larval settlement: A comparative transcriptomic approach

KAUST Repository

Chen, Zhang-Fan; Matsumura, Kiyotaka; Wang, Hao; Arellano, Shawn M.; Yan, Xingcheng; Alam, Intikhab; Archer, John A.C.; Bajic, Vladimir B.; Qian, Pei-Yuan

2011-01-01

of cyprids; 3) 20 kDa-cement protein homologues were expressed in the cyprid cement gland and probably function during attachment; and 4) receptor tyrosine kinases were expressed higher in cyprid stage and may be involved in signal perception during larval

Antifouling activities of marine sedentary invertebrates on some macrofoulers

Digital Repository Service at National Institute of Oceanography (India)

Wilsanand, V.; Wagh, A.B.; Bapuji, M.

pfeifferae, Dercitopsis sp.] against cyprids of the barnacle Balanus amphitrite and green mussel Perna viridis are reported here. All the extracts examined inhibited the settlement of cyprids of B. amphitrite. Toxicity revival studies indicate...

Larval vision contributes to gregarious settlement in barnacles: adult red fluorescence as a possible visual signal

KAUST Repository

Matsumura, K.

2014-02-26

Gregarious settlement, an essential behavior for many barnacle species that can only reproduce by mating with a nearby barnacle, has long been thought to rely on larval ability to recognize chemical signals from conspecifics during settlement. However, the cyprid, the settlement stage larva in barnacles, has one pair of compound eyes that appear only at the late nauplius VI and cyprid stages, but the function(s) of these eyes remains unknown. Here we show that cyprids of the intertidal barnacle Balanus (=Amphibalanus) amphitrite can locate adult barnacles even in the absence of chemical cues, and prefer to settle around them probably via larval sense of vision. We also show that the cyprids can discriminate color and preferred to settle on red surfaces. Moreover, we found that shells of adult B. amphitrite emit red auto-fluorescence and the adult extracts with the fluorescence as a visual signal attracted cyprid larvae to settle around it. We propose that the perception of specific visual signals can be involved in behavior of zooplankton including marine invertebrate larvae, and that barnacle auto-fluorescence may be a specific signal involved in gregarious larval settlement.

siRNA transfection in larvae of the barnacle Amphibalanus amphitrite

KAUST Repository

Zhang, G.

2015-06-25

RNA interference (RNAi) provides an efficient and specific technique for functional genomic studies. Yet, no successful application of RNAi has been reported in barnacles. In this study, siRNA against p38 MAPK was synthesized and then transfected into A. amphitrite larvae at either the nauplius or cyprid stage, or at both stages. Effects of siRNA transfection on the p38 MAPK level were hardly detectable in the cyprids when they were transfected at the nauplius stage. In contrast, larvae that were transfected at the cyprid stage showed lower levels of p38 MAPK than the blank and reagent controls. However, significantly decreased levels of phosphorylated p38 MAPK (pp38 MAPK) and reduced settlement rates were observed only in ‘double transfections’, in which larvae were exposed to siRNA solution at both the nauplius and cyprid stages. A relatively longer transfection time and more larval cells directly exposed to siRNA might explain the higher efficiency of double transfection experiments.

siRNA transfection in larvae of the barnacle Amphibalanus amphitrite

KAUST Repository

Zhang, G.; He, L.-S.; Wong, Y. H.; Yu, L.; Qian, P.-Y.

2015-01-01

RNA interference (RNAi) provides an efficient and specific technique for functional genomic studies. Yet, no successful application of RNAi has been reported in barnacles. In this study, siRNA against p38 MAPK was synthesized and then transfected into A. amphitrite larvae at either the nauplius or cyprid stage, or at both stages. Effects of siRNA transfection on the p38 MAPK level were hardly detectable in the cyprids when they were transfected at the nauplius stage. In contrast, larvae that were transfected at the cyprid stage showed lower levels of p38 MAPK than the blank and reagent controls. However, significantly decreased levels of phosphorylated p38 MAPK (pp38 MAPK) and reduced settlement rates were observed only in ‘double transfections’, in which larvae were exposed to siRNA solution at both the nauplius and cyprid stages. A relatively longer transfection time and more larval cells directly exposed to siRNA might explain the higher efficiency of double transfection experiments.

Trophic structure and biomass distribution of macrobenthos on ...

African Journals Online (AJOL)

The trophic structure and biomass of macrobenthos on both wave-sheltered, rocky intertidal shores and semi-exposed ones at seven localities in the Tsitsikamma Marine Protected Area were compared. In the Cochlear zone and entire intertidal (Cochlear- and Balanoid zones combined) biomass values of invertebrates and ...

The fish community of East Cape tidal pools and an assessment of ...

African Journals Online (AJOL)

Fish occurring in tidal pools in the lower balanoid zone near Port Elizabeth were examined by visual census and rotenone collections. Numerically, Clinidae constituted 28% of the community, Sparidae 23%, Gobiidae 17% and the Cheilodactylidae 12%, while eleven other families contributed to the remaining 20%. The 44 ...

Characterisation of the bacteria associated with barnacle, Balanus amphitrite, shell and their role in gregarious settlement of cypris larvae

Digital Repository Service at National Institute of Oceanography (India)

BacchettiDeGregoris, T.; Khandeparker, L.; Anil, A.C.; Mesbahi, E.; Burgess, J.G.; Clare, A.S.

bound to a surface (Crisp and Meadows, 1963). Accordingly, the SIPC is posited to act as a contact pheromone (Clare, 2011). However, barnacle shells in their natural environment are covered by biofilm; a thick layer composed of microbial cells embedded... of Skeletonema costatum (~2 x 10 5 cells/ml) until they reached the cyprid stage (approx. for 4–5 days). Cyprids were collected by filtering through a tier of filters (pore sizes of 350 and 250 μm) in order to discard nauplii and microalgae, and stored...

iTRAQ-Based Proteomic Profiling of the Barnacle Balanus amphitrite in Response to the Antifouling Compound Meleagrin

KAUST Repository

Han, Zhuang

2013-05-03

Marine biofouling refers to the unwanted accumulation of fouling organisms, such as barnacles, on artificial surfaces, resulting in severe consequences for marine industries. Meleagrin is a potential nontoxic antifoulant that is isolated from the fungus Penicillium sp.; however, its mechanistic effect mode of action on larval settlement remains unknown. Here, we applied iTRAQ coupled with 2D LC-MS/MS proteomic analysis to investigate the effect of meleagrin on the proteomic expression profile of cyprid development and aging in the barnacle Balanus amphitrite. Fifty proteins were differentially expressed in response to treatment with meleagrin, among which 26 proteins were associated with cyprid development/aging and 24 were specifically associated with the meleagrin treatment. The 66 proteins that were associated with aging only remained unaltered during exposure to meleagrin. Using KEGG analysis, those proteins were assigned to several groups, including metabolic pathways, ECM-receptor interactions, and the regulation of the actin cytoskeleton. Among the 24 proteins that were not related to the development/aging process, expression of the cyprid major protein (CMP), a vitellogenin-like protein, increased after the meleagrin treatment, which suggested that meleagrin might affect the endocrine system and prevent the larval molting cycle. With the exception of the chitin binding protein that mediates the molting process and ATPase-mediated energy processes, the majority of proteins with significant effects in previous studies in response to cyprid treatment with butenolide and polyether B remained unchanged in the present study, suggesting that meleagrin may exhibit a different mechanism. © 2013 American Chemical Society.

The regulatory role of the NO/cGMP signal transduction cascade during larval attachment and metamorphosis of the barnacle Balanus (=Amphibalanus) amphitrite

KAUST Repository

Zhang, Y.

2012-08-01

The barnacle Balanus amphitrite is among the most dominant fouling species on intertidal rocky shores in tropical and subtropical areas and is thus a target organism in antifouling research. After being released from adults, the swimming nauplius undertakes six molting cycles and then transforms into a cyprid. Using paired antennules, a competent cyprid actively explores and selects a suitable substratum for attachment and metamorphosis (collectively known as settlement). This selection process involves the reception of exogenous signals and subsequent endogenous signal transduction. To investigate the involvement of nitric oxide (NO) and cyclic GMP (cGMP) during larval settlement of B. amphitrite, we examined the effects of an NO donor and an NO scavenger, two nitric oxide synthase (NOS) inhibitors and a soluble guanylyl cyclase (sGC) inhibitor on settling cyprids. We found that the NO donor sodium nitroprusside (SNP) inhibited larval settlement in a dose-dependent manner. In contrast, both the NO scavenger carboxy-PTIO and the NOS inhibitors aminoguanidine hemisulfate (AGH) and S-methylisothiourea sulfate (SMIS) significantly accelerated larval settlement. Suppression of the downstream guanylyl cyclase (GC) activity using a GC-selective inhibitor ODQ could also significantly accelerate larval settlement. Interestingly, the settlement inhibition effects of SNP could be attenuated by ODQ at all concentrations tested. In the developmental expression profiling of NOS and sGC, the lowest expression of both genes was detected in the cyprid stage, a crucial stage for the larval decision to attach and metamorphose. In summary, we concluded that NO regulates larval settlement via mediating downstream cGMP signaling.

iTRAQ-Based Proteomic Profiling of the Barnacle Balanus amphitrite in Response to the Antifouling Compound Meleagrin

KAUST Repository

Han, Zhuang; Sun, Jin; Zhang, Yu; He, Fei; Xu, Ying; Matsumura, Kiyotaka; He, Li-Sheng; Qiu, Jian-Wen; Qi, Shu-Hua; Qian, Pei-Yuan

2013-01-01

Marine biofouling refers to the unwanted accumulation of fouling organisms, such as barnacles, on artificial surfaces, resulting in severe consequences for marine industries. Meleagrin is a potential nontoxic antifoulant that is isolated from the fungus Penicillium sp.; however, its mechanistic effect mode of action on larval settlement remains unknown. Here, we applied iTRAQ coupled with 2D LC-MS/MS proteomic analysis to investigate the effect of meleagrin on the proteomic expression profile of cyprid development and aging in the barnacle Balanus amphitrite. Fifty proteins were differentially expressed in response to treatment with meleagrin, among which 26 proteins were associated with cyprid development/aging and 24 were specifically associated with the meleagrin treatment. The 66 proteins that were associated with aging only remained unaltered during exposure to meleagrin. Using KEGG analysis, those proteins were assigned to several groups, including metabolic pathways, ECM-receptor interactions, and the regulation of the actin cytoskeleton. Among the 24 proteins that were not related to the development/aging process, expression of the cyprid major protein (CMP), a vitellogenin-like protein, increased after the meleagrin treatment, which suggested that meleagrin might affect the endocrine system and prevent the larval molting cycle. With the exception of the chitin binding protein that mediates the molting process and ATPase-mediated energy processes, the majority of proteins with significant effects in previous studies in response to cyprid treatment with butenolide and polyether B remained unchanged in the present study, suggesting that meleagrin may exhibit a different mechanism. © 2013 American Chemical Society.

The regulatory role of the NO/cGMP signal transduction cascade during larval attachment and metamorphosis of the barnacle Balanus (=Amphibalanus) amphitrite

KAUST Repository

Zhang, Y.; He, L.-S.; Zhang, G.; Xu, Y.; Lee, O.-O.; Matsumura, K.; Qian, P.-Y.

2012-01-01

The barnacle Balanus amphitrite is among the most dominant fouling species on intertidal rocky shores in tropical and subtropical areas and is thus a target organism in antifouling research. After being released from adults, the swimming nauplius undertakes six molting cycles and then transforms into a cyprid. Using paired antennules, a competent cyprid actively explores and selects a suitable substratum for attachment and metamorphosis (collectively known as settlement). This selection process involves the reception of exogenous signals and subsequent endogenous signal transduction. To investigate the involvement of nitric oxide (NO) and cyclic GMP (cGMP) during larval settlement of B. amphitrite, we examined the effects of an NO donor and an NO scavenger, two nitric oxide synthase (NOS) inhibitors and a soluble guanylyl cyclase (sGC) inhibitor on settling cyprids. We found that the NO donor sodium nitroprusside (SNP) inhibited larval settlement in a dose-dependent manner. In contrast, both the NO scavenger carboxy-PTIO and the NOS inhibitors aminoguanidine hemisulfate (AGH) and S-methylisothiourea sulfate (SMIS) significantly accelerated larval settlement. Suppression of the downstream guanylyl cyclase (GC) activity using a GC-selective inhibitor ODQ could also significantly accelerate larval settlement. Interestingly, the settlement inhibition effects of SNP could be attenuated by ODQ at all concentrations tested. In the developmental expression profiling of NOS and sGC, the lowest expression of both genes was detected in the cyprid stage, a crucial stage for the larval decision to attach and metamorphose. In summary, we concluded that NO regulates larval settlement via mediating downstream cGMP signaling.

Nontoxic piperamides and their synthetic analogues as novel antifouling reagents

KAUST Repository

Huang, Xiang-Zhong

2014-03-25

Bioassay-guided isolation of an acetone extract from a terrestrial plant Piper betle produced four known piperamides with potent antifouling (AF) activities, as evidenced by inhibition of settlement of barnacle cypris larvae. The AF activities of the four piperamides and 15 synthesized analogues were compared and their structure-activity relationships were probed. Among the compounds, piperoleine B and 1-[1-oxo-7-(3′,4′-methylenedioxyphenyl)-6E-heptenyl]-piperidine (MPHP) showed strong activity against settlement of cyprids of the barnacle Balanus amphitrite, having EC50 values of 1.1 ± 0.3 and 0.5 ± 0.2 μg ml-1, respectively. No toxicity against zebra fish was observed following incubation with these two compounds. Besides being non-toxic, 91% of piperoleine B-treated cyprids and 84% of MPHP-treated cyprids at a concentration of 100 μM completed normal metamorphosis in recovery bioassays, indicating that the anti-settlement effect of these two compounds was reversible. Hydrolysis and photolysis experiments indicated that MPHP could be decomposed in the marine environment. It is concluded that piperamides are promising compounds for use in marine AF coatings. © 2014 © 2014 Taylor & Francis.

Toward an understanding of the molecular mechanisms of barnacle larval settlement: A comparative transcriptomic approach

KAUST Repository

Chen, Zhang-Fan

2011-07-29

Background: The barnacle Balanus amphitrite is a globally distributed biofouler and a model species in intertidal ecology and larval settlement studies. However, a lack of genomic information has hindered the comprehensive elucidation of the molecular mechanisms coordinating its larval settlement. The pyrosequencing-based transcriptomic approach is thought to be useful to identify key molecular changes during larval settlement. Methodology and Principal Findings: Using 454 pyrosequencing, we collected totally 630,845 reads including 215,308 from the larval stages and 415,537 from the adults; 23,451 contigs were generated while 77,785 remained as singletons. We annotated 31,720 of the 92,322 predicted open reading frames, which matched hits in the NCBI NR database, and identified 7,954 putative genes that were differentially expressed between the larval and adult stages. Of these, several genes were further characterized with quantitative real-time PCR and in situ hybridization, revealing some key findings: 1) vitellogenin was uniquely expressed in late nauplius stage, suggesting it may be an energy source for the subsequent non-feeding cyprid stage; 2) the locations of mannose receptors suggested they may be involved in the sensory system of cyprids; 3) 20 kDa-cement protein homologues were expressed in the cyprid cement gland and probably function during attachment; and 4) receptor tyrosine kinases were expressed higher in cyprid stage and may be involved in signal perception during larval settlement. Conclusions: Our results provide not only the basis of several new hypotheses about gene functions during larval settlement, but also the availability of this large transcriptome dataset in B. amphitrite for further exploration of larval settlement and developmental pathways in this important marine species. © 2011 Chen et al.

Thielavins W–Z7, New Antifouling Thielavins from the Marine-Derived Fungus Thielavia sp. UST030930-004

KAUST Repository

Han, Zhuang; Li, Yong-Xin; Liu, Ling-Li; Lu, Liang; Guo, Xianrong; Zhang, Xixiang; Zhang, Xiao-Yong; Qi, Shu-Hua; Xu, Ying; Qian, Pei-Yuan

2017-01-01

Eleven new depsides-thielavins W-Z (1-4) and thielavins Z₁-Z₇ (5-11)-and also four known thielavins-A, H, J, and K (12-15)-were isolated from the ethyl acetate extract of a marine-derived fungal strain Thielavia sp UST030930-004. All of these compounds were evaluated for antifouling activity against cyprids of the barnacle Balanus (=Amphibalanus) amphitrite. The results showed that compounds 1-3 and 6-13 were active, with EC50 values ranging from 2.95 ± 0.59 to 69.19 ± 9.51 μM, respectively. The inhibitive effect of compounds 1-3 and 7 was reversible. This is the first description of the antifouling activity of thielavins against barnacle cyprids.

Thielavins W–Z7, New Antifouling Thielavins from the Marine-Derived Fungus Thielavia sp. UST030930-004

KAUST Repository

Han, Zhuang

2017-05-02

Eleven new depsides-thielavins W-Z (1-4) and thielavins Z₁-Z₇ (5-11)-and also four known thielavins-A, H, J, and K (12-15)-were isolated from the ethyl acetate extract of a marine-derived fungal strain Thielavia sp UST030930-004. All of these compounds were evaluated for antifouling activity against cyprids of the barnacle Balanus (=Amphibalanus) amphitrite. The results showed that compounds 1-3 and 6-13 were active, with EC50 values ranging from 2.95 ± 0.59 to 69.19 ± 9.51 μM, respectively. The inhibitive effect of compounds 1-3 and 7 was reversible. This is the first description of the antifouling activity of thielavins against barnacle cyprids.

Quantitative proteomics study of larval settlement in the barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan; Zhang, Huoming; Wang, Hao; Matsumura, Kiyotaka; Wong, Yue Him; Ravasi, Timothy; Qian, Pei-Yuan

2014-01-01

Barnacles are major sessile components of the intertidal areas worldwide, and also one of the most dominant fouling organisms in fouling communities. Larval settlement has a crucial ecological effect not only on the distribution of the barnacle population but also intertidal community structures. However, the molecular mechanisms involved in the transition process from the larval to the juvenile stage remain largely unclear. In this study, we carried out comparative proteomic profiles of stage II nauplii, stage VI nauplii, cyprids, and juveniles of the barnacle Balanus amphitrite using label-free quantitative proteomics, followed by the measurement of the gene expression levels of candidate proteins. More than 700 proteins were identified at each stage; 80 were significantly up-regulated in cyprids and 95 in juveniles vs other stages. Specifically, proteins involved in energy and metabolism, the nervous system and signal transduction were significantly up-regulated in cyprids, whereas proteins involved in cytoskeletal remodeling, transcription and translation, cell proliferation and differentiation, and biomineralization were up-regulated in juveniles, consistent with changes associated with larval metamorphosis and tissue remodeling in juveniles. These findings provided molecular evidence for the morphological, physiological and biological changes that occur during the transition process from the larval to the juvenile stages in B. amphitrite. © 2014 Chen et al.

Quantitative proteomics study of larval settlement in the barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan

2014-02-13

Barnacles are major sessile components of the intertidal areas worldwide, and also one of the most dominant fouling organisms in fouling communities. Larval settlement has a crucial ecological effect not only on the distribution of the barnacle population but also intertidal community structures. However, the molecular mechanisms involved in the transition process from the larval to the juvenile stage remain largely unclear. In this study, we carried out comparative proteomic profiles of stage II nauplii, stage VI nauplii, cyprids, and juveniles of the barnacle Balanus amphitrite using label-free quantitative proteomics, followed by the measurement of the gene expression levels of candidate proteins. More than 700 proteins were identified at each stage; 80 were significantly up-regulated in cyprids and 95 in juveniles vs other stages. Specifically, proteins involved in energy and metabolism, the nervous system and signal transduction were significantly up-regulated in cyprids, whereas proteins involved in cytoskeletal remodeling, transcription and translation, cell proliferation and differentiation, and biomineralization were up-regulated in juveniles, consistent with changes associated with larval metamorphosis and tissue remodeling in juveniles. These findings provided molecular evidence for the morphological, physiological and biological changes that occur during the transition process from the larval to the juvenile stages in B. amphitrite. © 2014 Chen et al.

Cirripede Cypris Antennules

DEFF Research Database (Denmark)

Chan, Benny K. K.; Sari, Alireza; Høeg, Jens Thorvald

2017-01-01

Barnacle cypris antennules are important for substratum attachment during settlement and on through metamorphosis from the larval stage to sessile adult. Studies on the morphology of cirripede cyprids are mostly qualitative, based on descriptions from images obtained using a scanning electron...... microscope (SEM). To our knowledge, our study is the first to use scanning electron microscopy to quantify overall structural diversity in cypris antennules by measuring 26 morphological parameters, including the structure of sensory organs. We analyzed cyprids from seven species of balanomorphan barnacles...... inhabiting rocky shore communities; for comparison, we also included a sponge-inhabiting balanomorphan and a verrucomorphan species. Multivariate analysis of the structural parameters resulted in two distinct clusters of species. From nonmetric multidimensional scaling plots, the sponge-inhabiting Balanus...

What do barnacle larvae feed on ? Implications in biofouling ecology

Digital Repository Service at National Institute of Oceanography (India)

Gaonkar, C.; Anil, A.C.

in experimental studies. Larval development in this barnacle includes planktotrophic naupliar stages followed by pre-settling cyprid instar. Studies have shown that availability of food during naupliar development is of critical importance to successful...

Thielavins W–Z7, New Antifouling Thielavins from the Marine-Derived Fungus Thielavia sp. UST030930-004

Directory of Open Access Journals (Sweden)

Zhuang Han

2017-04-01

Full Text Available Eleven new depsides—thielavins W–Z (1–4 and thielavins Z1–Z7 (5–11—and also four known thielavins—A, H, J, and K (12–15—were isolated from the ethyl acetate extract of a marine-derived fungal strain Thielavia sp UST030930-004. All of these compounds were evaluated for antifouling activity against cyprids of the barnacle Balanus (=Amphibalanus amphitrite. The results showed that compounds 1–3 and 6–13 were active, with EC50 values ranging from 2.95 ± 0.59 to 69.19 ± 9.51 μM, respectively. The inhibitive effect of compounds 1–3 and 7 was reversible. This is the first description of the antifouling activity of thielavins against barnacle cyprids.

Starvation threshold of Balanus amphitrite larvae in relation to temperature

Digital Repository Service at National Institute of Oceanography (India)

Anil, A.C.; Desai, D.V.

Energy content in the non-feeding (lecithotrophic) cyprid larvae of B. amphitrite plays an important role in determining its metamorphic characteristics. In this context it is important to understand the energy transformed to this stage from...

Metamorphosis in the Cirripede Crustacean Balanus amphitrite

Science.gov (United States)

Maruzzo, Diego; Aldred, Nick; Clare, Anthony S.; Høeg, Jens T.

2012-01-01

Stalked and acorn barnacles (Cirripedia Thoracica) have a complex life cycle that includes a free-swimming nauplius larva, a cypris larva and a permanently attached sessile juvenile and adult barnacle. The barnacle cyprid is among the most highly specialized of marine invertebrate larvae and its settlement biology has been intensively studied. By contrast, surprisingly few papers have dealt with the critical series of metamorphic events from cementation of the cyprid to the substratum until the appearance of a suspension feeding juvenile. This metamorphosis is both ontogenetically complex and critical to the survival of the barnacle. Here we use video microscopy to present a timeline and description of morphological events from settled cyprid to juvenile barnacle in the model species Balanus amphitrite, representing an important step towards both a broader understanding of the settlement ecology of this species and a platform for studying the factors that control its metamorphosis. Metamorphosis in B. amphitrite involves a complex sequence of events: cementation, epidermis separation from the cypris cuticle, degeneration of cypris musculature, rotation of the thorax inside the mantle cavity, building of the juvenile musculature, contraction of antennular muscles, raising of the body, shedding of the cypris cuticle, shell plate and basis formation and, possibly, a further moult to become a suspension feeding barnacle. We compare these events with developmental information from other barnacle species and discuss them in the framework of barnacle settlement ecology. PMID:22666355

The monophyletic origin of a remarkable sexual system in akentrogonid rhizocephalan parasites

DEFF Research Database (Denmark)

Glenner, Henrik; Høeg, Jens Thorvald; Stenderup, Jesper

2010-01-01

parasites. The Rhizocephala Akentrogonida form a monophyletic group nested within a paraphyletic "Kentrogonida". C. paguri and S. hippolytes are sistergroups confirming the monophyly of the Clistosaccidae that was originally based on similarities in the cypris larvae. We find numerous LM and SEM level...... similarities between the two species, many of which appear to be correlated with their specialized sexual system, where male cyprids use an antennule to implant cells into the virgin female parasite. Some of these traits are also found in cyprids of the thompsoniid species. We conclude that the special cypris...... morphology and the implantation of males by antennular penetration was present in the stem species to the Thompsoniidae and the Clistosaccidae and emphasize the power of larval characters in rhizocephalan systematics. C. delagei is a sister group to Boschmaella balani and the two are nested deep within...

Larval vision contributes to gregarious settlement in barnacles: adult red fluorescence as a possible visual signal

KAUST Repository

Matsumura, K.; Qian, P.-Y.

2014-01-01

surfaces. Moreover, we found that shells of adult B. amphitrite emit red auto-fluorescence and the adult extracts with the fluorescence as a visual signal attracted cyprid larvae to settle around it. We propose that the perception of specific visual signals

External morphology of the two cypridiform ascothoracid-larva instars of Dendrogaster: The evolutionary significance of the two-step metamorphosis and comparison of lattice organs between larvae and adult males (Crustacea, Thecostraca, Ascothoracida)

DEFF Research Database (Denmark)

Kolbasov, G.A.; Grygier, M.J.; Høeg, Jens Thorvald

2008-01-01

We describe the external morphology of the two cypridiform larval instars (first and second ascothoracid-larvae, or -a-cyprids") of the ascothoracidan genus Dendrogaster. Ascothoracid-larvae of five species were studied with light and scanning electron microscopy, including both ascothoracid-larv...

Cypris metamorphosis, injection and earliest internal development of theRrizocephalan Loxothylacus panopaei (Gissler). Crustacea: Cirripedia: Rhizocephala: Sacculinidae

DEFF Research Database (Denmark)

Glenner, H

2001-01-01

substratum and initiate metamorphosis. In the presumed sister group to Rhizocephala, the true barnacles or Thoracica, metamorphosis leads to a juvenile filter-feeding version of the adult organism. In Rhizocephala the female cyprid settles on the integument of a crustacean and undergoes metamorphosis...

Cirripede Cypris Antennules: How Much Structural Variation Exists Among Balanomorphan Species from Hard-Bottom Habitats?

Science.gov (United States)

Chan, Benny K K; Sari, Alireza; Høeg, Jens T

2017-10-01

Barnacle cypris antennules are important for substratum attachment during settlement and on through metamorphosis from the larval stage to sessile adult. Studies on the morphology of cirripede cyprids are mostly qualitative, based on descriptions from images obtained using a scanning electron microscope (SEM). To our knowledge, our study is the first to use scanning electron microscopy to quantify overall structural diversity in cypris antennules by measuring 26 morphological parameters, including the structure of sensory organs. We analyzed cyprids from seven species of balanomorphan barnacles inhabiting rocky shore communities; for comparison, we also included a sponge-inhabiting balanomorphan and a verrucomorphan species. Multivariate analysis of the structural parameters resulted in two distinct clusters of species. From nonmetric multidimensional scaling plots, the sponge-inhabiting Balanus spongicola and Verruca stroemia formed one cluster, while the other balanomorphan species, all from hard bottoms, grouped together in the other cluster. The shape of the attachment disk on segment 3 is the key parameter responsible for the separation into two clusters. The present results show that species from a coastal hard-bottom habitat may share a nearly identical antennular structure that is distinct from barnacles from other habitats, and this finding supports the fact that such species also have rather similar reactions to substratum cues during settlement. Any differences that may be found in settlement biology among such species must therefore be due either to differences in the properties of their adhesive mechanisms or to the way that sensory stimuli are detected by virtually identical setae and processed into settlement behavior by the cyprid.

Antifouling Activity of Synthetic Alkylpyridinium Polymers Using the Barnacle Model

Science.gov (United States)

Piazza, Veronica; Dragić, Ivanka; Sepčić, Kristina; Faimali, Marco; Garaventa, Francesca; Turk, Tom; Berne, Sabina

2014-01-01

Polymeric alkylpyridinium salts (poly-APS) isolated from the Mediterranean marine sponge, Haliclona (Rhizoniera) sarai, effectively inhibit barnacle larva settlement and natural marine biofilm formation through a non-toxic and reversible mechanism. Potential use of poly-APS-like compounds as antifouling agents led to the chemical synthesis of monomeric and oligomeric 3-alkylpyridinium analogues. However, these are less efficient in settlement assays and have greater toxicity than the natural polymers. Recently, a new chemical synthesis method enabled the production of poly-APS analogues with antibacterial, antifungal and anti-acetylcholinesterase activities. The present study examines the antifouling properties and toxicity of six of these synthetic poly-APS using the barnacle (Amphibalanus amphitrite) as a model (cyprids and II stage nauplii larvae) in settlement, acute and sub-acute toxicity assays. Two compounds, APS8 and APS12-3, show antifouling effects very similar to natural poly-APS, with an anti-settlement effective concentration that inhibits 50% of the cyprid population settlement (EC50) after 24 h of 0.32 mg/L and 0.89 mg/L, respectively. The toxicity of APS8 is negligible, while APS12-3 is three-fold more toxic (24-h LC50: nauplii, 11.60 mg/L; cyprids, 61.13 mg/L) than natural poly-APS. This toxicity of APS12-3 towards nauplii is, however, 60-fold and 1200-fold lower than that of the common co-biocides, Zn- and Cu-pyrithione, respectively. Additionally, exposure to APS12-3 for 24 and 48 h inhibits the naupliar swimming ability with respective IC50 of 4.83 and 1.86 mg/L. PMID:24699112

Antifouling Activity of Synthetic Alkylpyridinium Polymers Using the Barnacle Model

Directory of Open Access Journals (Sweden)

Veronica Piazza

2014-04-01

Full Text Available Polymeric alkylpyridinium salts (poly-APS isolated from the Mediterranean marine sponge, Haliclona (Rhizoniera sarai, effectively inhibit barnacle larva settlement and natural marine biofilm formation through a non-toxic and reversible mechanism. Potential use of poly-APS-like compounds as antifouling agents led to the chemical synthesis of monomeric and oligomeric 3-alkylpyridinium analogues. However, these are less efficient in settlement assays and have greater toxicity than the natural polymers. Recently, a new chemical synthesis method enabled the production of poly-APS analogues with antibacterial, antifungal and anti-acetylcholinesterase activities. The present study examines the antifouling properties and toxicity of six of these synthetic poly-APS using the barnacle (Amphibalanus amphitrite as a model (cyprids and II stage nauplii larvae in settlement, acute and sub-acute toxicity assays. Two compounds, APS8 and APS12-3, show antifouling effects very similar to natural poly-APS, with an anti-settlement effective concentration that inhibits 50% of the cyprid population settlement (EC50 after 24 h of 0.32 mg/L and 0.89 mg/L, respectively. The toxicity of APS8 is negligible, while APS12-3 is three-fold more toxic (24-h LC50: nauplii, 11.60 mg/L; cyprids, 61.13 mg/L than natural poly-APS. This toxicity of APS12-3 towards nauplii is, however, 60-fold and 1200-fold lower than that of the common co-biocides, Zn- and Cu-pyrithione, respectively. Additionally, exposure to APS12-3 for 24 and 48 h inhibits the naupliar swimming ability with respective IC50 of 4.83 and 1.86 mg/L.

Evidence for the Involvement of p38 MAPK Activation in Barnacle Larval Settlement

KAUST Repository

He, Li-Sheng

2012-10-24

The barnacle Balanus ( = Amphibalanus) amphitrite is a major marine fouling animal. Understanding the molecular mechanism of larval settlement in this species is critical for anti-fouling research. In this study, we cloned one isoform of p38 MAPK (Bar-p38 MAPK) from this species, which shares the significant characteristic of containing a TGY motif with other species such as yeast, Drosophila and humans. The activation of p38 MAPK was detected by an antibody that recognizes the conserved dual phosphorylation sites of TGY. The results showed that phospho-p38 MAPK (pp38 MAPK) was more highly expressed at the cyprid stage, particularly in aged cyprids, in comparison to other stages, including the nauplius and juvenile stages. Immunostaining showed that Bar-p38 MAPK and pp38 MAPK were mainly located at the cyprid antennules, and especially the third and fourth segments, which are responsible for substratum exploration during settlement. The expression and localization patterns of Bar-p38 MAPK suggest its involvement in larval settlement. This postulation was also supported by the larval settlement bioassay with the p38 MAPK inhibitor SB203580. Behavioral analysis by live imaging revealed that the larvae were still capable of exploring the surface of the substratum after SB203580 treatment. This shows that the effect of p38 MAPK on larval settlement might be by regulating the secretion of permanent proteinaceous substances. Furthermore, the level of pp38 MAPK dramatically decreased after full settlement, suggesting that Bar-p38 MAPK maybe plays a role in larval settlement rather than metamorphosis. Finally, we found that Bar-p38 MAPK was highly activated when larvae confronted extracts of adult barnacle containing settlement cues, whereas larvae pre-treated with SB203580 failed to respond to the crude adult extracts.

Evidence for the Involvement of p38 MAPK Activation in Barnacle Larval Settlement

KAUST Repository

He, Li-Sheng; Xu, Ying; Matsumura, Kiyotaka; Zhang, Yu; Zhang, Gen; Qi, Shu-Hua; Qian, Pei-Yuan

2012-01-01

The barnacle Balanus ( = Amphibalanus) amphitrite is a major marine fouling animal. Understanding the molecular mechanism of larval settlement in this species is critical for anti-fouling research. In this study, we cloned one isoform of p38 MAPK (Bar-p38 MAPK) from this species, which shares the significant characteristic of containing a TGY motif with other species such as yeast, Drosophila and humans. The activation of p38 MAPK was detected by an antibody that recognizes the conserved dual phosphorylation sites of TGY. The results showed that phospho-p38 MAPK (pp38 MAPK) was more highly expressed at the cyprid stage, particularly in aged cyprids, in comparison to other stages, including the nauplius and juvenile stages. Immunostaining showed that Bar-p38 MAPK and pp38 MAPK were mainly located at the cyprid antennules, and especially the third and fourth segments, which are responsible for substratum exploration during settlement. The expression and localization patterns of Bar-p38 MAPK suggest its involvement in larval settlement. This postulation was also supported by the larval settlement bioassay with the p38 MAPK inhibitor SB203580. Behavioral analysis by live imaging revealed that the larvae were still capable of exploring the surface of the substratum after SB203580 treatment. This shows that the effect of p38 MAPK on larval settlement might be by regulating the secretion of permanent proteinaceous substances. Furthermore, the level of pp38 MAPK dramatically decreased after full settlement, suggesting that Bar-p38 MAPK maybe plays a role in larval settlement rather than metamorphosis. Finally, we found that Bar-p38 MAPK was highly activated when larvae confronted extracts of adult barnacle containing settlement cues, whereas larvae pre-treated with SB203580 failed to respond to the crude adult extracts.

The effect of butenolide on behavioral and morphological changes in two marine fouling species, the barnacle Balanus amphitrite and the bryozoan Bugula neritina

KAUST Repository

Zhang, Yi Fan

2011-05-23

Butenolide [5-octylfuran-2(5H)-one] is a very promising antifouling compound. Here, the effects of butenolide on larval behavior and histology are compared in two major fouling organisms, viz. cypris larvae of Balanus amphitrite and swimming larvae of Bugula neritina. Butenolide diminished the positive phototactic behavior of B. amphitrite (EC50=0.82 μg ml(-1)) and B. neritina (EC50=3 μg ml(-1)). Its effect on the attachment of cyprids of B. amphitrite was influenced by temperature, and butenolide increased attachment of larvae of B. neritina to the bottom of the experimental wells. At concentrations of 4 μg ml(-1) and 10 μg ml(-1), butenolide decreased attachment of B. amphitrite and B. neritina, respectively, but the effects were reversible within a certain treatment time. Morphologically, butenolide inhibited the swelling of secretory granules and altered the rough endoplasmic reticulum (RER) in the cement gland of B. amphitrite cyprids. In B. neritina swimming larvae, butenolide reduced the number of secretory granules in the pyriform-glandular complex.

Barnacles and their significance in biofouling

Digital Repository Service at National Institute of Oceanography (India)

Anil, A.C.; Desai, D.V.; Khandeparker, L.; Gaonkar, C.A.

as severely as delayed metamorphosis, which may ultimately influence juvenile and adult population dynamics in the field. The physiological condition of the cyprids is largely determined by their energy reserve (i.e. larval feeding history) and physiological... coated multiwells. As earlier hypothesized by (Yule and Walker 1987) that sugars in solution adsorb electrostatically through – OH groups to polar groups associated with the cypris temporary adhesive (CTA), the detection of AE and deposition of foot...

Transcriptome and Proteome Studies Reveal Candidate Attachment Genes during the Development of the Barnacle Amphibalanus Amphitrite

KAUST Repository

Al-Aqeel, Sarah; Ryu, Tae Woo; Zhang, Huoming; Chandramouli, Kondethimmanahalli; Ravasi, Timothy

2016-01-01

The acorn barnacle, Balanus amphitrite, is the main biofouling organism in marine environments. In the present study we profiled the transcriptome and proteome of B. amphitrite at different life stages (nauplius II, nauplius VI, and cyprid) from the Red Sea, where the average water surface temperature is 34°C and the salinity reaches 41%. We identified 65,784 expressed contigs, and a total of 1387 expressed proteins measured by quantitative proteomics. We found that osmotic stress, salt stress, hyperosmotic response and the Wnt signaling pathway were strongly up-regulated during the planktonic stage, while the MAPK pathway, lipid metabolism, and cuticle development genes were down-regulated. In the transition stage between the nauplius VI and the cyprid, genes that are involved in blood coagulation, cuticle development and eggshell formation were highly up-regulated, while the nitric oxide pathway, which stimulates the swimming and feeding response in marine invertebrates, was down-regulated. We are able to report for the first time that sound sensory system proteins are highly abundant in the nauplius VI stage, implying that these proteins are good targets for the development of new antifouling compounds. The results presented here together with the new genome-wide datasets for a non-model specie represent an important resource for the study of biofouling and development. Proteomics data are available via ProteomeXchange with identifier PXD004679.

Transcriptome and proteome studies reveal candidate attachment genes during the development of the barnacle Amphibalanus Amphitrite

Directory of Open Access Journals (Sweden)

Sarah Al-Aqeel

2016-09-01

Full Text Available The acorn barnacle, Balanus amphitrite, is the main biofouling organism in marine environments. In the present study we profiled the transcriptome and proteome of B. amphitrite at different life stages (nauplius II, nauplius VI and cyprid from the Red Sea, where the average water surface temperature is 34°C and the salinity reaches 41‰. We identified 65,784 expressed contigs, and a total of 1,387 expressed proteins measured by quantitative proteomics. We found that osmotic stress, salt stress, hyperosmotic response and the Wnt signaling pathway were strongly up-regulated during the planktonic stage, while the MAPK pathway, lipid metabolism, and cuticle development genes were down-regulated. In the transition stage between the nauplius VI and the cyprid, genes that are involved in blood coagulation, cuticle development and eggshell formation were highly up-regulated, while the nitric oxide pathway, which stimulates the swimming and feeding response in marine invertebrates, was down-regulated. We are able to report for the first time that sound sensory system proteins are highly abundant in the nauplius VI stage, implying that these proteins are good targets for the development of new antifouling compounds. The results presented here together with the new genome-wide datasets for a non-model specie represent an important resource for the study of biofouling and development.

Transcriptome and Proteome Studies Reveal Candidate Attachment Genes during the Development of the Barnacle Amphibalanus Amphitrite

KAUST Repository

Al-Aqeel, Sarah

2016-09-21

The acorn barnacle, Balanus amphitrite, is the main biofouling organism in marine environments. In the present study we profiled the transcriptome and proteome of B. amphitrite at different life stages (nauplius II, nauplius VI, and cyprid) from the Red Sea, where the average water surface temperature is 34°C and the salinity reaches 41%. We identified 65,784 expressed contigs, and a total of 1387 expressed proteins measured by quantitative proteomics. We found that osmotic stress, salt stress, hyperosmotic response and the Wnt signaling pathway were strongly up-regulated during the planktonic stage, while the MAPK pathway, lipid metabolism, and cuticle development genes were down-regulated. In the transition stage between the nauplius VI and the cyprid, genes that are involved in blood coagulation, cuticle development and eggshell formation were highly up-regulated, while the nitric oxide pathway, which stimulates the swimming and feeding response in marine invertebrates, was down-regulated. We are able to report for the first time that sound sensory system proteins are highly abundant in the nauplius VI stage, implying that these proteins are good targets for the development of new antifouling compounds. The results presented here together with the new genome-wide datasets for a non-model specie represent an important resource for the study of biofouling and development. Proteomics data are available via ProteomeXchange with identifier PXD004679.

Gut fluorescence analysis of barnacle larvae: An approach to quantify the ingested food

Digital Repository Service at National Institute of Oceanography (India)

Gaonkar, C.A.; Anil, A.C.

of Oceanography, Dona Paula, Goa, India A B S T R A C T Gut fluorescence analysis can provide a snapshot of ingested food and has been employed in the feeding studies of various organisms. In this study we standardised the gut fluorescence method utilising... naupliar instars and a pre-settling cyprid instar. The I instar nauplius is non-feeding and moults into II instar within a short interval of time. II to VI instars are phytoplanktivorus. Nauplii obtained from the adult broods of the barnacle Balanus...

Studies on some cues regulating metamorphosis of the larvae of Balanus amphitrite (Cirripedia: Thoracica)

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, L.

glycoprotein present in the adults is thought to be responsible for this behavior (Knight-Jones 1953; Knight-Jones and Crisp 1953; Crisp and Meadows 1963). Clare et al. (1995) reported the involvement of cyclic AMP in the pheromonal modulation of barnacle.... amphitrite, Clare and Nott 1994) and suggests an analogy to the flicking action of decapod antennules (Schmidt and Ache 1979). Secondly, recent evidence has been obtained in support of the role of cAMP in cyprid settlement (Clare et al. 1995). A laser...

Factors regulating the production of different inducers in Pseudomonas aeruginosa with reference to larval metamorphosis in Balanus amphitrite

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, L.; Anil, A.C.; Raghukumar, S.

cyprids. Clare et al. (1995) provided evidence for the involvement of cyclic AMP (cAMP) in the settlement of this species. Yamamoto et al. (1996) have also reported that 5-hydroxytryptamine (5-HT) is involved in the larval settlement of barnacles. The need...) Evidence for the involvement of cyclic AMP in the pheromonal modulation of barnacle settlement. J Exp Biol 198:655–664 Crisp DJ (1974) Factors influencing the settlement of marine invertebrate larvae. In: Grant PT, Mackie AM (eds) Chemoreception in marine...

Metamorphosis in the cirripede crustacean Balanus amphitrite

DEFF Research Database (Denmark)

Maruzzo, Diego; Aldred, Nick; Clare, Anthony S.

2012-01-01

settlement biology has been intensively studied. By contrast, surprisingly few papers have dealt with the critical series of metamorphic events from cementation of the cyprid to the substratum until the appearance of a suspension feeding juvenile. This metamorphosis is both ontogenetically complex...... ecology of this species and a platform for studying the factors that control its metamorphosis. Metamorphosis in B. amphitrite involves a complex sequence of events: cementation, epidermis separation from the cypris cuticle, degeneration of cypris musculature, rotation of the thorax inside the mantle...

MKK3 Was Involved in Larval Settlement of the Barnacle Amphibalanus amphitrite through Activating the Kinase Activity of p38MAPK

KAUST Repository

Zhang, Gen

2013-07-29

The p38 mitogen-activated protein kinase (p38MAPK) plays a key role in larval settlement of the barnacle Amphibalanus amphitrite. To study the signaling pathway associated with p38MAPK during larval settlement, we sought to identify the upstream kinase of p38MAPK. Three MKKs (MKK3, MKK4 and MKK7) and three MAPKs (p38MAPK, ERK and JNK) in A. amphitrite were cloned and recombinantly expressed in E. coli. Through kinase assays, we found that MKK3, but not MKK4 or MKK7, phosphorylated p38MAPK. Furthermore, MKK3 activity was specific to p38MAPK, as it did not phosphorylate ERK or JNK. To further investigate the functional relationship between MKK3 and p38MAPK in vivo, we studied the localization of phospho-MKK3 (pMKK3) and MKK3 by immunostaining. Consistent with the patterns of p38MAPK and phospho-p38MAPK (pp38MAPK), pMKK3 and MKK3 mainly localized to the antennules of the cyprids. Western blot analysis revealed that pMKK3 levels, like pp38MAPK levels, were elevated at cyprid stage, compared to nauplii and juvenile stages. Moreover, pMKK3 levels increased after treatment with adult barnacle crude extracts, suggesting that MKK3 might mediate the stimulatory effects of adult barnacle extracts on the p38MAPK pathway. © 2013 Zhang et al.

MKK3 Was Involved in Larval Settlement of the Barnacle Amphibalanus amphitrite through Activating the Kinase Activity of p38MAPK

KAUST Repository

Zhang, Gen; He, Li-Sheng; Wong, Yue Him; Qian, Pei-Yuan

2013-01-01

The p38 mitogen-activated protein kinase (p38MAPK) plays a key role in larval settlement of the barnacle Amphibalanus amphitrite. To study the signaling pathway associated with p38MAPK during larval settlement, we sought to identify the upstream kinase of p38MAPK. Three MKKs (MKK3, MKK4 and MKK7) and three MAPKs (p38MAPK, ERK and JNK) in A. amphitrite were cloned and recombinantly expressed in E. coli. Through kinase assays, we found that MKK3, but not MKK4 or MKK7, phosphorylated p38MAPK. Furthermore, MKK3 activity was specific to p38MAPK, as it did not phosphorylate ERK or JNK. To further investigate the functional relationship between MKK3 and p38MAPK in vivo, we studied the localization of phospho-MKK3 (pMKK3) and MKK3 by immunostaining. Consistent with the patterns of p38MAPK and phospho-p38MAPK (pp38MAPK), pMKK3 and MKK3 mainly localized to the antennules of the cyprids. Western blot analysis revealed that pMKK3 levels, like pp38MAPK levels, were elevated at cyprid stage, compared to nauplii and juvenile stages. Moreover, pMKK3 levels increased after treatment with adult barnacle crude extracts, suggesting that MKK3 might mediate the stimulatory effects of adult barnacle extracts on the p38MAPK pathway. © 2013 Zhang et al.

A System-Wide Approach to Identify the Mechanisms of Barnacle Attachment: Toward the Discovery of New Antifouling Compounds

KAUST Repository

Al-Aqeel, Sarah

2015-11-01

Biofouling is a significant economic problem, particularly for marine and offshore oil industries. The acorn barnacle (Amphibalanus (Balanus) amphitrite) is the main biofouling organism in marine environments. Environmental conditions, the physiology of the biofouling organism, the surrounding microbial community, and the properties of the substratum can all influence the attachment of biofouling organisms to substrates. My dissertation investigated the biological processes involved in B. amphitrite development and attachment in the unique environment of the Red Sea, where the average water surface temperature is 34°C and the salinity reaches 41‰. I profiled the transcriptome and proteome of B. amphitrite at different life stages (nauplius II, nauplius VI, and cyprid) and identified 65,784 expressed contigs and 1387 expressed proteins by quantitative proteomics. During the planktonic stage, genes related to osmotic stress, salt stress, the hyperosmotic response, and the Wnt signaling pathway were strongly up-regulated, hereas genes related to the MAPK pathway, lipid metabolism, and cuticle development were down-regulated. In the transition from the nauplius VI to cyprid stages, there was up-regulation of genes involved in blood coagulation, cuticle development, and eggshell formation, and down-regulation of genes in the nitric oxide pathway, which stimulates the swimming and feeding responses of marine invertebrates. This system-wide integrated approach elucidated the development and attachment pathways important in B. amphitrite. Enzymes and metabolites in these pathways are potential molecular targets for the development of new antifouling compounds.

Molecular characterization of the α-subunit of Na⁺/K⁺ ATPase from the euryhaline barnacle Balanus improvisus reveals multiple genes and differential expression of alternative splice variants.

Directory of Open Access Journals (Sweden)

Ulrika Lind

Full Text Available The euryhaline bay barnacle Balanus improvisus has one of the broadest salinity tolerances of any barnacle species. It is able to complete its life cycle in salinities close to freshwater (3 PSU up to fully marine conditions (35 PSU and is regarded as one of few truly brackish-water species. Na⁺/K⁺ ATPase (NAK has been shown to be important for osmoregulation when marine organisms are challenged by changing salinities, and we therefore cloned and examined the expression of different NAKs from B. improvisus. We found two main gene variants, NAK1 and NAK2, which were approximately 70% identical at the protein level. The NAK1 mRNA existed in a long and short variant with the encoded proteins differing only by 27 N-terminal amino acids. This N-terminal stretch was coded for by a separate exon, and the two variants of NAK1 mRNAs appeared to be created by alternative splicing. We furthermore showed that the two NAK1 isoforms were differentially expressed in different life stages and in various tissues of adult barnacle, i.e the long isoform was predominant in cyprids and in adult cirri. In barnacle cyprid larvae that were exposed to a combination of different salinities and pCO2 levels, the expression of the long NAK1 mRNA increased relative to the short in low salinities. We suggest that the alternatively spliced long variant of the Nak1 protein might be of importance for osmoregulation in B. improvisus in low salinity conditions.

Journal of Naval Science. Volume 2. Number 3. July 1976

Science.gov (United States)

1976-07-01

supplementary food to the beakers containing stage VI nauplii: cyprids do not feed. The larvae in each beaker were con- fined within a close-fitting plastic...99-274% of Natural U) Uranium-234 (234U) (0-006% of Natural U) 2-48 X 10"’yrs Thorium-230 (230Th) Polonium -218(2I8Po) /through short lived...Natural U) Actinium-227 (--7Ac) FIG. 1. Nuclide chart. 4-51 X 10’Yrs 7 hours P 8 X 10’ Yrs 4 days Lead- 210 (210Pb) (22 yrs,/3"). 1-39 X 10

Antifouling effect of bioactive compounds from marine sponge Acanthella elongata and different species of bacterial film on larval attachment of Balanus amphitrite (cirripedia, crustacea

Directory of Open Access Journals (Sweden)

Viswambaran Ganapiriya

2012-06-01

Full Text Available The antifouling activity of bioactive compounds from marine sponge Acanthella elongata (Dendy and five species of bacterial biofilm were studied. Larvae of Balanus amphitrite (Cyprids and nauplii were used to monitor the settlement inhibition and the extent to which inhibition was due to toxicity. The crude extract and partially purified fractions of A.elongata showed significant inhibition over the settlement individually, and with the interaction of bacterial species. No bacterial film stimulated the barnacle settlement. The high but variable levels of antifouling activity in combination with less amount of toxicity showed the potential of these metabolites in environmentally-friendly antifouling preparations.

Characterization of Two 20kDa-Cement Protein (cp20k) Homologues in Amphibalanus amphitrite

KAUST Repository

He, Li-Sheng

2013-05-22

The barnacle, Amphibalanus amphitrite, is a common marine fouling organism. Understanding the mechanism of barnacle adhesion will be helpful in resolving the fouling problem. Barnacle cement is thought to play a key role in barnacle attachment. Although several adult barnacle cement proteins have been identified in Megabalanus rosa, little is known about their function in barnacle settlement. In this study, two homologous 20k-cement proteins (cp20k) in Amphibalanus amphitrite, named Bamcp20k-1 and Bamcp20k-2, were characterized. The two homologues share primary sequence structure with proteins from other species including Megabalanus rosa and Fistulobalanus albicostatus. The conserved structure included repeated Cys domains and abundant charged amino acids, such as histidine. In this study we demonstrated that Bamcp20k-1 localized at the α secretory cells in the cyprid cement gland, while Bamcp20k-2 localized to the β secretory cells. The differential localizations suggest differential regulation for secretion from the secretory cells. Both Bamcp20k-1 and Bamcp20k-2 from cyprids dissolved in PBS. However, adult Bamcp20k-2, which was dominant in the basal shell of adult barnacles, was largely insoluble in PBS. Solubility increased in the presence of the reducing reagent Dithiothreitol (DTT), suggesting that the formation of disulfide bonds plays a role in Bamcp20k-2 function. In comparison, Bamcp20k-1, which was enriched in soft tissue, could not be easily detected in the shell and base by Western blot and easily dissolved in PBS. These differential solubilities and localizations indicate that Bamcp20k-1 and Bamcp20k-2 have distinct functions in barnacle cementing. © 2013 He et al.

Characterization of Two 20kDa-Cement Protein (cp20k) Homologues in Amphibalanus amphitrite

KAUST Repository

He, Li-Sheng; Zhang, Gen; Qian, Pei-Yuan

2013-01-01

The barnacle, Amphibalanus amphitrite, is a common marine fouling organism. Understanding the mechanism of barnacle adhesion will be helpful in resolving the fouling problem. Barnacle cement is thought to play a key role in barnacle attachment. Although several adult barnacle cement proteins have been identified in Megabalanus rosa, little is known about their function in barnacle settlement. In this study, two homologous 20k-cement proteins (cp20k) in Amphibalanus amphitrite, named Bamcp20k-1 and Bamcp20k-2, were characterized. The two homologues share primary sequence structure with proteins from other species including Megabalanus rosa and Fistulobalanus albicostatus. The conserved structure included repeated Cys domains and abundant charged amino acids, such as histidine. In this study we demonstrated that Bamcp20k-1 localized at the α secretory cells in the cyprid cement gland, while Bamcp20k-2 localized to the β secretory cells. The differential localizations suggest differential regulation for secretion from the secretory cells. Both Bamcp20k-1 and Bamcp20k-2 from cyprids dissolved in PBS. However, adult Bamcp20k-2, which was dominant in the basal shell of adult barnacles, was largely insoluble in PBS. Solubility increased in the presence of the reducing reagent Dithiothreitol (DTT), suggesting that the formation of disulfide bonds plays a role in Bamcp20k-2 function. In comparison, Bamcp20k-1, which was enriched in soft tissue, could not be easily detected in the shell and base by Western blot and easily dissolved in PBS. These differential solubilities and localizations indicate that Bamcp20k-1 and Bamcp20k-2 have distinct functions in barnacle cementing. © 2013 He et al.

Gregarious settlement in cypris larvae: the effects of cyprid age and assay duration

NARCIS (Netherlands)

Head, R.M.; Berntsson, K.M.; Dahlström, M.; Overbeke, J.C.; Thomason, J.C.

2004-01-01

Gregarious behaviour of marine larvae is perhaps most clearly associated with finding a suitable habitat in a changeable or restricted environment, or with finding other conspecifics with which to mate. Prior work has shown that in settlement assays using cypris larvae of the barnacle Balanus

Plutonium diffusion in the marine environment: a quantitative study on marine species of the channel shores, from Brest to Honfleur

International Nuclear Information System (INIS)

Fraizier, A.; Guary, J.C.

1977-01-01

Plutonium levels were measured on marine species of the Channel shores, from Cancale to Honfleur in 1975, from Brest to the Cap de La Hague in 1976. Measurements carried out on a lichen: Lichina pygmaea, two algae: Corallina officinalis and Fucus serratus, a spongiae: Hymeniacidon sanguinea and a crustacean: Balanus balanoides, showed the effect of waste disposal from a fuel reprocessing plant on the radioactivity levels of these organisms. This effect, decreasing progressively appeared at distances of at least 150 km from the point of release. As compared to the values observed for samples taken as the far west end of Brittany and also to the plutonium levels in the marine environment resulting from atmosphere fallout only, the levels observed in the studied area were higher and varying according to the geographic position, increasing by a factor of 100 near the emissary. These data are an actual instance of radioactive dispersal following disposal into the sea; they should bring valuable information for the assessment of the radiological capacity of a given coastal area [fr

Plutonium diffusion in the marine environment: a quantitative study on marine species of the channel shores, from Brest (St Mathieu Point) to Honfleur

International Nuclear Information System (INIS)

Fraizier, Albert; Guary, J.-C.

1977-03-01

Plutonium levels were measured on marine species of the Channel shores, from Cancale to Honfleur in 1975, from Brest to the Cap de La Hague in 1976. Measurements carried out on a lichen: Lichina pygmaea, two algae: Corallina officinalis and Fucus serratus, a spongiae: Hymeniacidon sanguinea and a crustacean: Balamus balanoides, showed the effect of waste disposal from La Hague fuel reprocessing plant on the radioactivity levels of these organisms. This effect, decreasing progressively, appeared at distances of about 150 km from the point of release. As compared to value observed for samples taken at the far West of Brittany and to plutonium levels in the marine environment resulting from atmospheric fallout only, the levels observed in the studied area were higher and varying according to the geographic position, increasing by a factor of 100 near the emissary. These data are an actual instance of radioactive dispersal following disposal into the sea; they should bring valuable information for the assessment of the radiological capacity of a given coastal area [fr

Comparative Proteome and Phosphoproteome Analyses during Cyprid Development of the Barnacle Balanus ( =Amphibalanus ) amphitrite

KAUST Repository

Zhang, Yu; Xu, Ying; Arellano, Shawn M.; Xiao, Kang; Qian, Pei Yuan

2010-01-01

examined with a two-dimensional electrophoresis (2-DE) multiplexed fluorescent staining approach. Optimized protein separation strategies, including solution-phase isoelectric fractionation and narrow-pH-range 2-DE, were used in a proteomic analysis. Our

Marine Biofouling of Surfaces: Morphology, and Nanomechanics of Barnacle Cyprid Adhesion Proteins by AFM

NARCIS (Netherlands)

Phang, In Yee

2008-01-01

The understanding of biointerfaces in contact with seawater is crucially important in tackling the problems of marine biofouling. Such biointerfaces involve the bioadhesives used by marine organisms to attach temporary or permanently to the surfaces immersed in water. The aim of this Thesis is to

Spatial structure of the meroplankton community along a Patagonian fjord - The role of changing freshwater inputs

Science.gov (United States)

Meerhoff, Erika; Tapia, Fabián J.; Castro, Leonardo R.

2014-12-01

Freshwater inputs are major drivers of circulation, hydrographic structure, and productivity patterns along estuarine systems. We assessed the degree to which meroplankton community structure in the Baker/Martinez fjord complex (Chilean Patagonia, 47.5°S) responds to spatial and temporal changes in hydrographic conditions driven by seasonal changes in Baker river outflow. Zooplankton and hydrographic measurements were conducted along the fjord in early spring (October) and late summer (February), when river outflow was minimal and maximal, respectively. Major meroplankton groups found on these surveys were larval barnacles, crabs, bivalves and gastropods. There was a clear change in community structure between October and February, explained by a switch in the numerically dominant group from barnacle to bivalve larvae. This change in community structure was related to changes in hydrographic structure along the fjord, which are mainly associated with seasonal changes in the Baker river outflow. A variance partition analysis showed no significant spatial trend that could account for the variation in meroplankton along the Martinez channel, whereas temporal variability and environmental variables accounted for 36.6% and 27.6% of the variance, respectively. When comparing meroplankton among the Baker and Martinez channels in October, changes in environmental variables explained 44.9% of total variance, whereas spatial variability accounted for 23.5%. Early and late-stage barnacle larvae (i.e. nauplii and cyprids) were more abundant in water with lower temperature, and higher dissolved oxygen and chlorophyll-a concentration, whereas bivalve larvae were more strongly associated to warmer waters. The seasonal shift in numerical dominance, from barnacle larvae in early spring to bivalve larvae in late summer, suggests that reproduction of these groups is triggered by substantially different sets of conditions, both in terms of hydrography and food availability. The

Larval development and metamorphosis in Balanus amphitrite Darwin (Cirripedia; Thoracica): Significance of food concentration, temperature and nucleic acids

Digital Repository Service at National Institute of Oceanography (India)

Anil, A.C.; Desai, D.V.; Khandeparker, L.

concentration. Bars represent standard deviation. Ž 5 y1 concentrations at 208Cat2=10 cells ml DNA: Ys0.13 xq1.34 mg, rs0.79, pF0.001; RNA: Ys0.18 xq1.44 mg, rs0.59, pF0.001; and at 1=10 5 cells ml y1 DNA: Ys0.05 xq1.76 mg, rs0.57, pF0.01; RNA: Ys0.02 xq1.85 mg... , g and h represent larvae raised at 208Cat2=10 5 cells ml y1 . ()A.C. Anil et al.rJ. Exp. Mar. Biol. Ecol. 263 2001 125–141136 length ranging from 421 to 448 mm and total breadth from 211 to 230 mm. A regression analysis of the day of cyprid emergence...

Effects of poly-ether B on proteome and phosphoproteome expression in biofouling Balanus amphitrite cyprids

KAUST Repository

Dash, Swagatika; Chandramouli, Kondethimmanahalli; Zhang, Yu; Qian, Pei Yuan

2012-01-01

in recent years, although the mechanism by which they inhibit fouling is yet to be investigated. Poly-ether B has shown promise in the non-toxic inhibition of larval barnacle attachment. Hence, in this study, multiplex two-dimensional electrophoresis (2-DE

Antifouling Metabolites from the Mangrove Plant Ceriops tagal

Directory of Open Access Journals (Sweden)

Yi Ming Lin

2008-01-01

Full Text Available The new diterpene methoxy-ent-8(14-pimarenely-15-one (1 and three knownmetabolites: ent-8(14-pimarene-15R,16-diol (2, stigmasterol (3 and β-sitosterol (4, wereisolated from the roots of the mangrove plant Ceriops tagal. Their structures and relativestereochemistry were elucidated by means of extensive NMR, IR and MS analysis.Compounds 1, 2, 3 and 4 exhibited significant antifouling activities against cyprid larvaeof the barnacle Balanus albicostatus Pilsbry, with EC50 values of 0.32 ± 0.01, 0.04 ± 0.00,4.05 ± 0.15 and 18.47 ± 0.40 μg/cm2, respectively, whereas their toxicities towards cypridswere very low, with LC50 values all above 10 μg/cm2.

Exploration and metamorphosis in Balanus amphitrite Darwin (Cirripedia ; Thoracica) cyprids: significance of sugars and adult extract

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, L.; Anil, A.C.; Raghukumar, S.

(AE) have been suggested to be involved in the settlement of Balanus amphitrite. In the present study experiments were carried out to assess how cypris larvae would explore and metamorphose when treated with LCA specific sugars (i.e. D-glucose and D...

Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample

Science.gov (United States)

Guo, Shifeng; Zhu, Xiaoying; Jańczewski, Dominik; Lee, Serina Siew Chen; He, Tao; Teo, Serena Lay Ming; Vancso, G. Julius

2016-09-01

Protein charge at various pH and isoelectric point (pI) values is important in understanding protein function. However, often only trace amounts of unknown proteins are available and pI measurements cannot be obtained using conventional methods. Here, we show a method based on the atomic force microscope (AFM) to determine pI using minute quantities of proteins. The protein of interest is immobilized on AFM colloidal probes and the adhesion force of the protein is measured against a positively and a negatively charged substrate made by layer-by-layer deposition of polyelectrolytes. From the AFM force-distance curves, pI values with an estimated accuracy of ±0.25 were obtained for bovine serum albumin, myoglobin, fibrinogen and ribonuclease A over a range of 4.7-9.8. Using this method, we show that the pI of the ‘footprint’ of the temporary adhesive proteins secreted by the barnacle cyprid larvae of Amphibalanus amphitrite is in the range 9.6-9.7.

Biologically-Oriented Processes in the Coastal Sea Ice Zone of the White Sea

Science.gov (United States)

Melnikov, I. A.

2002-12-01

The annual advance and retreat of sea ice is a major physical determinant of spatial and temporal changes in the structure and function of marine coastal biological communities. Sea ice biological data obtained in the tidal zone of Kandalaksha Gulf (White Sea) during 1996-2001 period will be presented. Previous observations in this area were mainly conducted during the ice-free summer season. However, there is little information on the ice-covered winter season (6-7 months duration), and, especially, on the sea-ice biology in the coastal zone within tidal regimes. During the January-May period time-series observations were conducted on transects along shorelines with coastal and fast ice. Trends in the annual extent of sea ice showed significant impacts on ice-associated biological communities. Three types of sea ice impact on kelps, balanoides, littorinas and amphipods are distinguished: (i) positive, when sea ice protects these populations from grinding (ii) negative, when ice grinds both fauna and flora, and (iii) a combined effect, when fast ice protects, but anchored ice grinds plant and animals. To understand the full spectrum of ecological problems caused by pollution on the coastal zone, as well as the problems of sea ice melting caused by global warming, an integrated, long-term study of the physical, chemical, and biological processes is needed.

Design and Biological Evaluation of Antifouling Dihydrostilbene Oxime Hybrids.

Science.gov (United States)

Moodie, Lindon W K; Cervin, Gunnar; Trepos, Rozenn; Labriere, Christophe; Hellio, Claire; Pavia, Henrik; Svenson, Johan

2018-04-01

By combining the recently reported repelling natural dihydrostilbene scaffold with an oxime moiety found in many marine antifoulants, a library of nine antifouling hybrid compounds was developed and biologically evaluated. The prepared compounds were shown to display a low antifouling effect against marine bacteria but a high potency against the attachment and growth of microalgae down to MIC values of 0.01 μg/mL for the most potent hybrid. The mode of action can be characterized as repelling via a reversible non-toxic biostatic mechanism. Barnacle cyprid larval settlement was also inhibited at low μg/mL concentrations with low levels or no toxicity observed. Several of the prepared compounds performed better than many reported antifouling marine natural products. While several of the prepared compounds are highly active as antifoulants, no apparent synergy is observed by incorporating the oxime functionality into the dihydrostilbene scaffold. This observation is discussed in light of recently reported literature data on related marine natural antifoulants and antifouling hybrids as a potentially general strategy for generation of improved antifoulants.

Antifouling Activity of Secondary Metabolites Isolated from Chinese Marine Organisms

KAUST Repository

Li, Yong Xin

2013-04-25

Biofouling results in tremendous economic losses to maritime industries around the world. A recent global ban on the use of organotin compounds as antifouling agents has further raised demand for safe and effective antifouling compounds. In this study, 49 secondary metabolites, including diterpenoids, steroids, and polyketides, were isolated from soft corals, gorgonians, brown algae, and fungi collected along the coast of China, and their antifouling activity was tested against cyprids of the barnacle Balanus (Amphibalanus) amphitrite. Twenty of the compounds were found to inhibit larval settlement significantly at a concentration of 25 μg ml-1. Two briarane diterpenoids, juncin O (2) and juncenolide H (3), were the most promising non-toxic antilarval settlement candidates, with EC50 values less than 0.13 μg ml-1 and a safety ratio (LC50/EC50) higher than 400. A preliminary structure-activity relationships study indicated that both furanon and furan moieties are important for antifouling activity. Intriguingly, the presence of hydroxyls enhanced their antisettlement activity. © 2013 Springer Science+Business Media New York.

Antifouling Activity of Secondary Metabolites Isolated from Chinese Marine Organisms

KAUST Repository

Li, Yong Xin; Wu, Hui Xian; Xu, Ying; Shao, Chang Lun; Wang, Chang Yun; Qian, Pei Yuan

2013-01-01

Biofouling results in tremendous economic losses to maritime industries around the world. A recent global ban on the use of organotin compounds as antifouling agents has further raised demand for safe and effective antifouling compounds. In this study, 49 secondary metabolites, including diterpenoids, steroids, and polyketides, were isolated from soft corals, gorgonians, brown algae, and fungi collected along the coast of China, and their antifouling activity was tested against cyprids of the barnacle Balanus (Amphibalanus) amphitrite. Twenty of the compounds were found to inhibit larval settlement significantly at a concentration of 25 μg ml-1. Two briarane diterpenoids, juncin O (2) and juncenolide H (3), were the most promising non-toxic antilarval settlement candidates, with EC50 values less than 0.13 μg ml-1 and a safety ratio (LC50/EC50) higher than 400. A preliminary structure-activity relationships study indicated that both furanon and furan moieties are important for antifouling activity. Intriguingly, the presence of hydroxyls enhanced their antisettlement activity. © 2013 Springer Science+Business Media New York.

Influence of bacterial exopolymers, conspecific adult extract and salinity on the cyprid metamorphosis of Balanus amphitrite (Cirripedia: Thoracica)

Digital Repository Service at National Institute of Oceanography (India)

Anil, A.C.; Khandeparker, R.

salinities. The epm extracted from the pool of these three strains (mixed culture) was also tested similarly. The influence of epm varied with the strain of bacteria and salinity. The surface condition and time interval significantly influenced...

Hydrogel brushes grafted from stainless steel via surface-initiated atom transfer radical polymerization for marine antifouling

Science.gov (United States)

Wang, Jingjing; Wei, Jun

2016-09-01

Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings.

Influence of bacterial exopolymers and the adult extract of Balanus amphitrite and Cthamalus sp. on cyprid metamorphosis of Balanus amphitrite

Digital Repository Service at National Institute of Oceanography (India)

Anil, A.C.; Khandeparker, L.; Mitbavkar, S.; Wagh, A.B.

play a major role in the recruitment of larvae of fouling organisms, probably by providing inducing/inhibitory chemical cues. In this experiment, the influence of the extract of adult Balanus amphitrite and the expolymers of the bacteria colonising...

Notes on the ultrastructure of the setae on the fourth antennulary segment of the Balanus amphitrite cyprid (Crustacea : Cirripedia : Thoracica)

DEFF Research Database (Denmark)

Lagersson, Niklas; Garm, Anders Lydik; Høeg, Jens Thorvald

2003-01-01

This study presents electron microscopy (SEM, TEM) observations on the putative settlement receptors of the fourth antennulary segments. The TEM data from all nine setae are from the outer dendritic segment. Eight of them have morphological characteristics, indicating bimodal sensory properties...... while one seta (sE) is presumed to be a unimodal mechanoreceptor. We suggest that setae A and B are stimulated by the water flow, seta D is olfactory, seta E detects the topography of the substratum by touch, and the subterminal setae are touch chemoreceptors. No function is suggested for seta C....

A New Diketopiperazine from the Marine Sponge Callyspongia Species

Directory of Open Access Journals (Sweden)

Bin Yang

2016-01-01

Full Text Available Chemical investigation of the sponge Callyspongia sp . from the South China Sea afforded one new diketopiperazine , cyclo-(R-Pro-6-hydroxyl-S -Ile (1, along with six known d iketopiperazines : staphyloamide A (2, cyclo- (S-Pro-S-Phe (3, cyclo-(R-Pro-R-Phe (4, cyclo- (S-Pro-R-Leu (5 , cyclo-(S-Pro-R-Ala (6, cyclo-(R-Tyr-R-Phe (7, and three known tryptophan-derived alkaloids: C 2-α-D-mannosylpyranosyl-tryptophan (8, (1 R , 3 S -1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylic acid (9, and (1R,3R-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylic acid (10 . The structures were determined on the basis of NMR and MS analysis , and the absolute configuration was determined by comparison of the optical rotation with the known compounds. This is the first report of compounds 1, 2 , 8–10 from the sponge Callyspongia . Cyclo- (S-Pro-R-Leu (5 , and cyclo-(S-Pro-R-Ala (6 exhibited antifouling activity against cyprid larvae of the barnacle with the LC 50 values of 3.5 μg/cm 2 and 6.0 μg/cm 2, respectively .

Effects of Toxic Leachate from Commercial Plastics on Larval Survival and Settlement of the Barnacle Amphibalanus amphitrite.

Science.gov (United States)

Li, Heng-Xiang; Getzinger, Gordon J; Ferguson, P Lee; Orihuela, Beatriz; Zhu, Mei; Rittschof, Daniel

2016-01-19

Plastic pollution represents a major and growing global problem. It is well-known that plastics are a source of chemical contaminants to the aquatic environment and provide novel habitats for marine organisms. The present study quantified the impacts of plastic leachates from the seven categories of recyclable plastics on larval survival and settlement of barnacle Amphibalanus (=Balanus) amphitrite. Leachates from plastics significantly increased barnacle nauplii mortality at the highest tested concentrations (0.10 and 0.50 m(2)/L). Hydrophobicity (measured as surface energy) was positively correlated with mortality indicating that plastic surface chemistry may be an important factor in the effects of plastics on sessile organisms. Plastic leachates significantly inhibited barnacle cyprids settlement on glass at all tested concentrations. Settlement on plastic surfaces was significantly inhibited after 24 and 48 h, but settlement was not significantly inhibited compared to the controls for some plastics after 72-96 h. In 24 h exposure to seawater, we found larval toxicity and inhibition of settlement with all seven categories of recyclable commercial plastics. Chemical analysis revealed a complex mixture of substances released in plastic leachates. Leaching of toxic compounds from all plastics should be considered when assessing the risks of plastic pollution.

Antifouling phenyl ethers and other compounds from the invertebrates and their symbiotic fungi collected from the South China Sea.

Science.gov (United States)

Wang, Chao-Yi; Wang, Kai-Ling; Qian, Pei-Yuan; Xu, Ying; Chen, Min; Zheng, Juan-Juan; Liu, Min; Shao, Chang-Lun; Wang, Chang-Yun

2016-12-01

Marine organism-derived secondary metabolites are promising potential sources for discovering environmentally safe antifouling agents. In present study, 55 marine secondary metabolites and their synthesized derivatives were tested and evaluated for their antifouling activities and security. These compounds include 44 natural products isolated from marine invertebrates and their symbiotic microorganisms collected from the South China Sea and 11 structural modified products derived from the isolated compounds. The natural secondary metabolites, covering phenyl ether derivatives, terpenoids, 9, 11-secosteroids, anthraquinones, alkaloids, nucleoside derivatives and peptides, were isolated from two corals, one sponge and five symbiotic fungi. All of the isolated and synthesized compounds were tested for their antifouling activities against the cyprids of barnacle Balanus (Amphibalanus) amphitrite Darwin. Noticeably, five phenyl ether derivatives (9, 11, 13-15) exhibited potent anti-larval settlement activity with the EC 50 values lower than 3.05 μM and the LC 50 /EC 50 ratios higher than 15. The study of structure-activity relationship (SAR) revealed that the introduction of acetoxy groups and bromine atoms to phenyl ether derivatives could significantly improve their antifouling activities. This is the first report on the SAR of phenyl ether derivatives on antifouling activity against barnacle B. amphitrite. The polybrominated diphenyl ether derivative, 2, 4, 6, 2', 4', 6'-hexabromo-diorcinol (13), which displayed excellent antifouling activity, was considered as a promising candidate of environmentally friendly antifouling agents.

Characterization of Terpenoids from the Root of Ceriops tagal with Antifouling Activity

Science.gov (United States)

Chen, Jun-De; Yi, Rui-Zao; Lin, Yi-Ming; Feng, Dan-Qing; Zhou, Hai-Chao; Wang, Zhan-Chang

2011-01-01

One new dimeric diterpenoid, 8(14)-enyl-pimar-2′(3′)-en-4′(18′)-en-15′(16′)-endolabr- 16,15,2′,3′-oxoan-16-one (1) and five known terpenoids: Tagalsin C (2), Tagalsin I (3), lup-20(29)-ene-3β,28-diol (4), 3-oxolup-20(29)-en-28-oic acid (5) and 28-hydroxylup- 20(29)-en-3-one (6) were isolated from the roots of the mangrove plant Ceriops tagal. Their structures and relative stereochemistry were elucidated by means of extensive NMR, IR and MS analysis. The antifouling activity against larval settlement of the barnacle Balanus albicostatus were evaluated using capsaicin as a positive control. All these terpenoids exhibited antifouling activity against cyprid larvae of the barnacle without significant toxicity. The structure-activity relationship results demonstrated that the order of antifouling activity was diterpenoid (Compound 2) > triterpenoid (Compounds 4, 5 and 6) > dimeric diterpenoid (Compounds 1 and 3). The functional groups on the C-28 position of lupane triterpenoid significantly affect the antifouling activity. The diterpenoid dimmer with two identical diterpenoid subunits might display more potent antifouling activity than one with two different diterpenoid subunits. The stability test showed that Compounds 2, 4, 5 and 6 remained stable over 2-month exposure under filtered seawater. PMID:22072902

Hydrogel brushes grafted from stainless steel via surface-initiated atom transfer radical polymerization for marine antifouling

Energy Technology Data Exchange (ETDEWEB)

Wang, Jingjing, E-mail: jjwang1@hotmail.com; Wei, Jun

2016-09-30

Highlights: • Crosslinked hydrogel brushes were grafted from SS surfaces for marine antifouling. • All brush-coated SS surfaces could effectively reduce the adhesion of biofouling. • The antifouling efficacy increased with the crosslinking density of hydrogels. - Abstract: Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings.

Hydrogel brushes grafted from stainless steel via surface-initiated atom transfer radical polymerization for marine antifouling

International Nuclear Information System (INIS)

Wang, Jingjing; Wei, Jun

2016-01-01

Highlights: • Crosslinked hydrogel brushes were grafted from SS surfaces for marine antifouling. • All brush-coated SS surfaces could effectively reduce the adhesion of biofouling. • The antifouling efficacy increased with the crosslinking density of hydrogels. - Abstract: Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings.

Evaluation of low copper content antifouling paints containing natural phenolic compounds as bioactive additives.

Science.gov (United States)

Pérez, Miriam; García, Mónica; Blustein, Guillermo

2015-08-01

Cuprous oxide is the most commonly used biocide in antifouling paints. However, copper has harmful effects not only on the fouling community but also on non-target species. In the current study, we investigated the use of thymol, eugenol and guaiacol in this role combined with small quantities of copper. Phenolic compounds were tested for anti-settlement activity against cyprid larvae of the barnacle Balanus amphitrite and for their toxicity to nauplius larvae. Thymol, eugenol and guaiacol were active for anti-settlement but guaiacol had the disadvantage of being toxic to nauplius larvae. However, all of them showed therapeutic ratio>1. Antifouling paints with thymol (low copper content/thymol, LCP/T), eugenol (low copper content/eugenol, LCP/E) and guaiacol (low copper content/guaiacol, LCP/G) combined with small copper content were formulated for field trials. After 12 months exposure in the sea, statistical analysis revealed that LCP/T and LCP/E paints were the most effective combinations and had similar performances to control paints with high copper content (traditional cuprous oxide based paints). In contrast, LCP/G paint was only partially effective in preventing and inhibiting biofouling and was colonized by some hard and soft foulers. However, this antifouling paint was effective against calcareous tubeworm Hydroides elegans. In the light of various potential applications, thymol, eugenol and guaiacol have thus to be considered in future antifouling formulations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antifouling phenyl ethers and other compounds from the invertebrates and their symbiotic fungi collected from the South China Sea

KAUST Repository

Wang, Chao-Yi

2016-10-26

Marine organism-derived secondary metabolites are promising potential sources for discovering environmentally safe antifouling agents. In present study, 55 marine secondary metabolites and their synthesized derivatives were tested and evaluated for their antifouling activities and security. These compounds include 44 natural products isolated from marine invertebrates and their symbiotic microorganisms collected from the South China Sea and 11 structural modified products derived from the isolated compounds. The natural secondary metabolites, covering phenyl ether derivatives, terpenoids, 9, 11-secosteroids, anthraquinones, alkaloids, nucleoside derivatives and peptides, were isolated from two corals, one sponge and five symbiotic fungi. All of the isolated and synthesized compounds were tested for their antifouling activities against the cyprids of barnacle Balanus (Amphibalanus) amphitrite Darwin. Noticeably, five phenyl ether derivatives (9, 11, 13–15) exhibited potent anti-larval settlement activity with the EC50 values lower than 3.05 μM and the LC50/EC50 ratios higher than 15. The study of structure–activity relationship (SAR) revealed that the introduction of acetoxy groups and bromine atoms to phenyl ether derivatives could significantly improve their antifouling activities. This is the first report on the SAR of phenyl ether derivatives on antifouling activity against barnacle B. amphitrite. The polybrominated diphenyl ether derivative, 2, 4, 6, 2′, 4′, 6′-hexabromo-diorcinol (13), which displayed excellent antifouling activity, was considered as a promising candidate of environmentally friendly antifouling agents.

The Mode of Action of Isocyanide in Three Aquatic Organisms, Balanus amphitrite, Bugula neritina and Danio rerio

KAUST Repository

Zhang, Yi-Fan

2012-09-18

Isocyanide is a potential antifouling compound in marine environments. In this study, we investigated its mode of action in three aquatic organisms. Two of them, the bryozoan Bugula neritina and the barnacle Balanus amphitrite, are major marine fouling invertebrates, and the other organism is the non-target species zebrafish Danio rerio. In the swimming larvae of B. neritina, isocyanide did not affect the total attachment rate (≤50 µg ml^(−1)), but it did change the attachment site by increasing the percentage of attachment on the bottom of the container rather than on the wall or air-water inter-surface. Isocyanide binds several proteins in B. neritina as identified via SDS-PAGE-LC-MS/MS: 1) a 30 kD protein band containing two proteins similar to voltage dependent anion channels (VDAC), which control the direct coupling of the mitochondrial matrix to the energy maintenance of the cytosol and the release of apoptogenic factors from mitochondria of mammalian cells; and 2) an unknown 39 kD protein. In B. amphitrite cyprids, the isocyanide binding protein were 1) a protein similar to NADH-ubiquinone oxidoreductase, which is the “entry enzyme” of oxidative phosphorylation in mitochondria; and 2) cytochrome P450. In Danio rerio embryos, isocyanide caused “wavy” notochords, hydrocephalus, pericardial edema, poor blood circulation, and defects in pigmentation and hematopoiesis, which phenocopied copper deficiency. This is the first report on isocyanide binding proteins in fouling organisms, as well as the first description of its phenotype and potential toxicology in zebrafish.

Expression of Calmodulin and Myosin Light Chain Kinase during Larval Settlement of the Barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan; Wang, Hao; Matsumura, Kiyotaka; Qian, Pei-Yuan

2012-01-01

Barnacles are one of the most common organisms in intertidal areas. Their life cycle includes seven free-swimming larval stages and sessile juvenile and adult stages. The transition from the swimming to the sessile stages, referred to as larval settlement, is crucial for their survivor success and subsequent population distribution. In this study, we focused on the involvement of calmodulin (CaM) and its binding proteins in the larval settlement of the barnacle, Balanus (= Amphibalanus) amphitrite. The full length of CaM gene was cloned from stage II nauplii of B. amphitrite (referred to as Ba-CaM), encoding 149 amino acid residues that share a high similarity with published CaMs in other organisms. Quantitative real-time PCR showed that Ba-CaM was highly expressed in cyprids, the stage at which swimming larvae are competent to attach and undergo metamorphosis. In situ hybridization revealed that the expressed Ba-CaM gene was localized in compound eyes, posterior ganglion and cement glands, all of which may have essential functions during larval settlement. Larval settlement assays showed that both the CaM inhibitor compound 48/80 and the CaM-dependent myosin light chain kinase (MLCK) inhibitor ML-7 effectively blocked barnacle larval settlement, whereas Ca 2+/CaM-dependent kinase II (CaMKII) inhibitors did not show any clear effects. The subsequent real-time PCR assay showed a higher expression level of Ba-MLCK gene in larval stages than in adults, suggesting an important role of Ba-MLCK gene in larval development and competency. Overall, the results suggest that CaM and CaM-dependent MLCK function during larval settlement of B. amphitrite. © 2012 Chen et al.

Expression of Calmodulin and Myosin Light Chain Kinase during Larval Settlement of the Barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan

2012-02-13

Barnacles are one of the most common organisms in intertidal areas. Their life cycle includes seven free-swimming larval stages and sessile juvenile and adult stages. The transition from the swimming to the sessile stages, referred to as larval settlement, is crucial for their survivor success and subsequent population distribution. In this study, we focused on the involvement of calmodulin (CaM) and its binding proteins in the larval settlement of the barnacle, Balanus (= Amphibalanus) amphitrite. The full length of CaM gene was cloned from stage II nauplii of B. amphitrite (referred to as Ba-CaM), encoding 149 amino acid residues that share a high similarity with published CaMs in other organisms. Quantitative real-time PCR showed that Ba-CaM was highly expressed in cyprids, the stage at which swimming larvae are competent to attach and undergo metamorphosis. In situ hybridization revealed that the expressed Ba-CaM gene was localized in compound eyes, posterior ganglion and cement glands, all of which may have essential functions during larval settlement. Larval settlement assays showed that both the CaM inhibitor compound 48/80 and the CaM-dependent myosin light chain kinase (MLCK) inhibitor ML-7 effectively blocked barnacle larval settlement, whereas Ca 2+/CaM-dependent kinase II (CaMKII) inhibitors did not show any clear effects. The subsequent real-time PCR assay showed a higher expression level of Ba-MLCK gene in larval stages than in adults, suggesting an important role of Ba-MLCK gene in larval development and competency. Overall, the results suggest that CaM and CaM-dependent MLCK function during larval settlement of B. amphitrite. © 2012 Chen et al.

Ostracod calcite records the 18O/16O ratio of the bicarbonate and carbonate ions in water

Science.gov (United States)

Devriendt, Laurent S.; McGregor, Helen V.; Chivas, Allan R.

2017-10-01

The δ18O of ostracod valves is widely used to infer water δ18O and temperature. However, ostracod δ18O appears sensitive to other environmental variables. In addition, there is species-dependent ostracod calcite 18O enrichment, relative to slowly precipitated inorganic calcite under the same conditions. Together these uncertainties complicate ostracod paleoclimate reconstructions. This study presents a new understanding of the causes of ostracod δ18O variations based on a global database of published ostracod δ18O values in lake, marine and coastal environments, and from culture experiments. The database includes associated field/experiment host water parameters including temperature (-1 to 32 °C), water δ18O (-13.2‰ to 4.3‰ VSMOW), pH (6.9-10.4), salinity (0-72 g/kg), calcite saturation states (0.6-26), and dissolved inorganic carbon concentration [DIC] (0.9-54.3 mmol/kg). The data show that: (1) the δ18O of marine and non-marine ostracods reflects the 18O/16O of the sum of host water CO32- and HCO3- ions. For example, at a given temperature, the δ18O of non-marine ostracods decreases by 4‰ to 6‰ as [CO32-]/[DIC] reaches 70%, depending on the ostracod species. In low [CO32-]/[DIC] settings (i.e. high HCO3-/CO32-), ostracod 18O/16O is close to the 18O/16O of HCO3- ions, which explains why on average ostracod δ18O is higher than the δ18O of inorganic calcite precipitated slowly under the same conditions. (2) Taxonomic offsets in ostracod δ18O vary with the host water [CO32-]/[DIC]. In environments where HCO3- ≫ CO32- (i.e. most freshwater lakes), the 18O/16O of Candonids is indistinguishable from the 18O/16O of HCO3- ions (difference of 0.10 ± 0.16‰) while the 18O/16O of Cyprids is lower than the 18O/16O of HCO3- ions by -0.77‰ to -0.32‰, Cytherids by -0.88 ± 0.29‰, and Limnocytherids by -1.12 ± 0.05‰. (3) The sensitivity of ostracod δ18O to [CO32-]/[DIC] also varies with taxonomy. For each percent increase in [CO32-]/[DIC

Transcriptomic Analysis of Neuropeptides and Peptide Hormones in the Barnacle Balanus amphitrite: Evidence of Roles in Larval Settlement

Science.gov (United States)

Yan, Xing-Cheng; Chen, Zhang-Fan; Sun, Jin; Matsumura, Kiyotaka; Wu, Rudolf S. S.; Qian, Pei-Yuan

2012-01-01

The barnacle Balanus amphitrite is a globally distributed marine crustacean and has been used as a model species for intertidal ecology and biofouling studies. Its life cycle consists of seven planktonic larval stages followed by a sessile juvenile/adult stage. The transitional processes between larval stages and juveniles are crucial for barnacle development and recruitment. Although some studies have been conducted on the neuroanatomy and neuroactive substances of the barnacle, a comprehensive understanding of neuropeptides and peptide hormones remains lacking. To better characterize barnacle neuropeptidome and its potential roles in larval settlement, an in silico identification of putative transcripts encoding neuropeptides/peptide hormones was performed, based on transcriptome of the barnacle B. amphitrite that has been recently sequenced. Potential cleavage sites andstructure of mature peptides were predicted through homology search of known arthropod peptides. In total, 16 neuropeptide families/subfamilies were predicted from the barnacle transcriptome, and 14 of them were confirmed as genuine neuropeptides by Rapid Amplification of cDNA Ends. Analysis of peptide precursor structures and mature sequences showed that some neuropeptides of B. amphitrite are novel isoforms and shared similar characteristics with their homologs from insects. The expression profiling of predicted neuropeptide genes revealed that pigment dispersing hormone, SIFamide, calcitonin, and B-type allatostatin had the highest expression level in cypris stage, while tachykinin-related peptide was down regulated in both cyprids and juveniles. Furthermore, an inhibitor of proprotein convertase related to peptide maturation effectively delayed larval metamorphosis. Combination of real-time PCR results and bioassay indicated that certain neuropeptides may play an important role in cypris settlement. Overall, new insight into neuropeptides/peptide hormones characterized in this study shall

Transcriptomic analysis of neuropeptides and peptide hormones in the barnacle Balanus amphitrite: evidence of roles in larval settlement.

KAUST Repository

Yan, Xing-Cheng

2012-10-02

The barnacle Balanus amphitrite is a globally distributed marine crustacean and has been used as a model species for intertidal ecology and biofouling studies. Its life cycle consists of seven planktonic larval stages followed by a sessile juvenile/adult stage. The transitional processes between larval stages and juveniles are crucial for barnacle development and recruitment. Although some studies have been conducted on the neuroanatomy and neuroactive substances of the barnacle, a comprehensive understanding of neuropeptides and peptide hormones remains lacking. To better characterize barnacle neuropeptidome and its potential roles in larval settlement, an in silico identification of putative transcripts encoding neuropeptides/peptide hormones was performed, based on transcriptome of the barnacle B. amphitrite that has been recently sequenced. Potential cleavage sites andstructure of mature peptides were predicted through homology search of known arthropod peptides. In total, 16 neuropeptide families/subfamilies were predicted from the barnacle transcriptome, and 14 of them were confirmed as genuine neuropeptides by Rapid Amplification of cDNA Ends. Analysis of peptide precursor structures and mature sequences showed that some neuropeptides of B. amphitrite are novel isoforms and shared similar characteristics with their homologs from insects. The expression profiling of predicted neuropeptide genes revealed that pigment dispersing hormone, SIFamide, calcitonin, and B-type allatostatin had the highest expression level in cypris stage, while tachykinin-related peptide was down regulated in both cyprids and juveniles. Furthermore, an inhibitor of proprotein convertase related to peptide maturation effectively delayed larval metamorphosis. Combination of real-time PCR results and bioassay indicated that certain neuropeptides may play an important role in cypris settlement. Overall, new insight into neuropeptides/peptide hormones characterized in this study shall

Transcriptomic analysis of neuropeptides and peptide hormones in the barnacle Balanus amphitrite: evidence of roles in larval settlement.

Directory of Open Access Journals (Sweden)

Xing-Cheng Yan

Full Text Available The barnacle Balanus amphitrite is a globally distributed marine crustacean and has been used as a model species for intertidal ecology and biofouling studies. Its life cycle consists of seven planktonic larval stages followed by a sessile juvenile/adult stage. The transitional processes between larval stages and juveniles are crucial for barnacle development and recruitment. Although some studies have been conducted on the neuroanatomy and neuroactive substances of the barnacle, a comprehensive understanding of neuropeptides and peptide hormones remains lacking. To better characterize barnacle neuropeptidome and its potential roles in larval settlement, an in silico identification of putative transcripts encoding neuropeptides/peptide hormones was performed, based on transcriptome of the barnacle B. amphitrite that has been recently sequenced. Potential cleavage sites andstructure of mature peptides were predicted through homology search of known arthropod peptides. In total, 16 neuropeptide families/subfamilies were predicted from the barnacle transcriptome, and 14 of them were confirmed as genuine neuropeptides by Rapid Amplification of cDNA Ends. Analysis of peptide precursor structures and mature sequences showed that some neuropeptides of B. amphitrite are novel isoforms and shared similar characteristics with their homologs from insects. The expression profiling of predicted neuropeptide genes revealed that pigment dispersing hormone, SIFamide, calcitonin, and B-type allatostatin had the highest expression level in cypris stage, while tachykinin-related peptide was down regulated in both cyprids and juveniles. Furthermore, an inhibitor of proprotein convertase related to peptide maturation effectively delayed larval metamorphosis. Combination of real-time PCR results and bioassay indicated that certain neuropeptides may play an important role in cypris settlement. Overall, new insight into neuropeptides/peptide hormones characterized in

Transcriptomic analysis of neuropeptides and peptide hormones in the barnacle Balanus amphitrite: evidence of roles in larval settlement.

KAUST Repository

Yan, Xing-Cheng; Chen, Zhang-Fan; Sun, Jin; Matsumura, Kiyotaka; Wu, Rudolf S S; Qian, Pei-Yuan

2012-01-01

The barnacle Balanus amphitrite is a globally distributed marine crustacean and has been used as a model species for intertidal ecology and biofouling studies. Its life cycle consists of seven planktonic larval stages followed by a sessile juvenile/adult stage. The transitional processes between larval stages and juveniles are crucial for barnacle development and recruitment. Although some studies have been conducted on the neuroanatomy and neuroactive substances of the barnacle, a comprehensive understanding of neuropeptides and peptide hormones remains lacking. To better characterize barnacle neuropeptidome and its potential roles in larval settlement, an in silico identification of putative transcripts encoding neuropeptides/peptide hormones was performed, based on transcriptome of the barnacle B. amphitrite that has been recently sequenced. Potential cleavage sites andstructure of mature peptides were predicted through homology search of known arthropod peptides. In total, 16 neuropeptide families/subfamilies were predicted from the barnacle transcriptome, and 14 of them were confirmed as genuine neuropeptides by Rapid Amplification of cDNA Ends. Analysis of peptide precursor structures and mature sequences showed that some neuropeptides of B. amphitrite are novel isoforms and shared similar characteristics with their homologs from insects. The expression profiling of predicted neuropeptide genes revealed that pigment dispersing hormone, SIFamide, calcitonin, and B-type allatostatin had the highest expression level in cypris stage, while tachykinin-related peptide was down regulated in both cyprids and juveniles. Furthermore, an inhibitor of proprotein convertase related to peptide maturation effectively delayed larval metamorphosis. Combination of real-time PCR results and bioassay indicated that certain neuropeptides may play an important role in cypris settlement. Overall, new insight into neuropeptides/peptide hormones characterized in this study shall

Environmentally Benign and Permanent Modifications to Prevent Biofouling on Marine and Hydrokinetic Devices

Energy Technology Data Exchange (ETDEWEB)

Zheng Zhang

2012-04-19

fouling release coating were used for comparison. Compared with the unmodified silicone substrates, the sulfobetaine-modified formulations were able to exhibit a 98% reduction in fibrinogen adsorption, 97.0% (E. coli), 99.6% (S. aureus), and 99.5% (C. lytica) reduction in bacteria attachment, and 100% reduction in barnacles cyprid attachment. In addition to the significant improvement in fouling resistance of various organisms, the 60-day field test also showed an evident efficacy from visual assessment, foul rating, and fouling removal test. The research confirmed that the novel antifouling mechanism of betaine polymers provides a new avenue for marine coating development. The developed coatings out-performed currently used nontoxic underwater coatings in a broad spectrum of fouling resistance. By further developing formulations and processing methods for specific devices, the technology is ready for the next stage of development with demonstration in MHK systems.