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1.
Dendropoma maximum is a vermetid gastropod (a sessile tube-forming snail) commonly associated with living corals throughout shallow-water reefs of the Indo-Pacific. Recent work suggests that, once established, this species can adversely affect growth and survival of corals. Here, we test the hypotheses that disturbances to live coral substrates (e.g., creation of bare patches) facilitate successful larval settlement and subsequent population growth of D. maximum, and conversely, that live coral inhibits D. maximum settlement. In the shallow lagoon of Moorea, French Polynesia, we selected patch reefs where D. maximum was either present or absent (to evaluate potential effects of resident adult conspecifics on recruitment) and established focal quadrats on each reef. In each quadrat, we either experimentally removed 50 % of live coral cover or left the quadrat with 100 % live coral cover. In addition, we deployed units of bare substrate (coral rubble) to each reef. We conducted a census of deployed substrates and quadrats after 6 months and found that D. maximum settled irrespective of resident vermetid populations, and only onto nonliving surfaces (i.e., cleared patches in quadrats, coral rubble, and marine epoxy). In laboratory experiments, we exposed larvae of D. maximum to live coral and found species-specific effects on survival of D. maximum larvae. Porites lobata and Pocillopora sp. killed larvae of D. maximum, Porites rus caused weaker mortality, and Millepora sp. had no effect on larval survival. Collectively, these results suggest that D. maximum requires disturbances that create bare patches to successfully settle onto reefs, and that a high cover of living corals contributes resilience to reefs by limiting settlement opportunities of a species known to reduce coral growth and survival.  相似文献   

2.
Coral species are difficult to discern because of their morphological plasticity, long generation times, and slow rates of mitochondrial DNA evolution. Among Caribbean representatives of the genus Porites are three named species (P. divaricata, P. furcata, and P. porites) with branching colony morphologies whose validity as genetically isolated species has been debated. We present sequence data from the mitochondrial control region, nuclear ITS, and nine single-copy nuclear loci for the Caribbean Porites and a related eastern Pacific species. mtDNA sequences were nearly invariant among the three branching species and their crustose sister P. branneri, and ITS sequences from these four were intermingled. An information theoretic analysis provided no support for upholding the three named Caribbean branching species. Both a clustering analysis and an analysis of molecular variance showed that sequence variation from the three branching forms is partitioned more by geography than by taxonomy. Multi-locus coalescent phylogenetic analysis provided a calibrated estimate for the nuclear DNA substitution rate (0.14 % Ma?1) close to that for other corals. Because no generalities have emerged from genetic investigations of the validity of morphologically defined coral species, the use of single-copy nuclear data is likely to be important in testing problematic species designations.  相似文献   

3.
Reefs of Andaman and Nicobar Islands harbour 418 species of scleractinian corals spread over an area of 2,000 km2. In April to May, 2010, due to the delayed onset of the southwest monsoon the sea surface temperature of the coastal and oceanic region increased to 31.7 °C in respect to the earlier record of maximum 29.0 °C during the said period. This resulted in mass bleaching of hermatypic corals during May, 2010. Rapid under water surveys have been conducted in reefs of Andaman and Nicobar Islands to assess the health of corals between May 2010 and August 2011. It is estimated that 76.62 ± (SD) 10.83 % of coral species are bleached up to a water depth of 10–15 m. Species from the genus Acropora appeared more susceptible to bleaching than those belong to the genus Porites. During the month of June 2010 the sea surface temperature was reduced to 29 °C perhaps due to the rainfall which stimulated rebuilding of zooxanthellae population in bleached corals. Recovery of 85.54 ± (SD) 6.33 % of bleached corals was seen during the study period of 11 months after the bleaching event. Porites spp. showed a high recovery rate, while Acropora spp. had the highest mortality rate. Coral mortality can have profound ecological and socio-economical implications and highlights the need for sustained monitoring for coral reef conservation in India. Hence, steps must be taken to improve management tools to protect these resources of global significance.  相似文献   

4.
Seasonal predatory and scavenger arthropod densities were studied at interior and coastal southern California poultry ranches. Though some seasonal population clumping occurred with some species, the distribution of predators and scavengers was fairly uniform within each ranch. Correlation analyses of key predators in theHisteridae, Staphylinidae, Hydrophylidae andDermaptera with the potential hosts,Musca domestica L.,Tinea fuscipunctella Haworth, andFannia spp. suggested that predator activity was seasonally influenced. Possible periodic avoidance of a particular host's habitat was detected as significant negative correlations. The data tend to support the importance of different species of predators in different seasons and the need for natural enemy complexes rather than single species for biological control.  相似文献   

5.
The diversity of coral associated fungi is not enough understood, especially for scleractinian corals. Members of Porites are common and dominant species of scleractinian corals. To date, the fungal communities associated with coral Porites pukoensis have been not reported. In this paper, the diversity and activity of coral associated fungi in P. pukoensis were explored, 23 fungal strains were isolated, belonging to 10 genera and Aspergillus sp. (30.4 %) was predominant fungal genera. The sequence of isolate C1-23 in GenBank was only 90 % similarity to the most closely related sequences. It is concluded that rich fungal symbionts are attached to P. pukoensis, the rate of isolates with antibacterial activity was up to 30 %, particularly some isolates showed stronger bioactivities to gram-negative bacteria. It is included that the diversity of coral associated fungi in P. pukoensis is abundant and its activity is obviously. So the activities of fungi in P. pukoensis were deserved for further study.  相似文献   

6.
Intracolony or syngeneic transplants of pieces of living coral, either occurring naturally on reefs or produced experimentally, were consistently compatible. In contrast, intercolony allografts performed extensively inAcropora formosa and inPorites andrewsii were incompatible, as were allografts occurring naturally in additional species observed in reef communities. Diverse interspecific combinations of coral xenografts generally displayed greater incompatibilities. Four levels of immuno-reactivity, with manifestations ranging from mild to severe, were distinguishable as follows: a) contact avoidance reactions, b) allogeneic contact incompatibility, c) chronic xenogeneic incompatibility, and d) acute interspecific aggression.Allogeneic incompatibility, most studied inA. formosa, was characterized by soft tissue contact avoidance wherever possible; absence of tissue death despite extensive enforced contact (18–20 days); and late interfacial cementation terminating allogeneic soft tissue contact. The properties ofchronic xenogeneic incompatibility as found in diverse species combinations, are slow onset (>7 days), bidirectional or unidirectional killing in contact zones, and short-range or localized effectiveness.Acute interspecific aggression initiated byFungia fungites as a dominant “aggressor ” is distinguished by early occurrence (2–7 days) and unidirectional contact killing. The presence or absence of these acute xenogeneic reactions sharply discriminated between species within each of the generaAcropora, Pocillopora, andPorites. No hierarchy of aggressive interactions was evident at the generic level.  相似文献   

7.
Marine fishes reach their highest diversity in coral reef ecosystems, which they utilize as territory, place of refuge and reproduction, and source of food. One type of predation among reef fishes is feeding on coral polyps, and a single, easily identifiable family of fishes, Chaetodontidae, contains the majority of obligate corallivore species. Multiple studies have examined the behaviour and ecology of Chaetodontidae and their relationship with the benthic habitat. However, many questions remain about their feeding ecology and food specifity at the species level. The present study is the first attempt to systematically decipher the feeding behavior of the obligate corallivore, Chaetodon octofasciatus. Field data were collected from four sites in the Thousand Islands, Indonesia, during two sampling campaigns in 2006, covering two seasons and two different depths. A high abundance of C. octofasciatus was positively related to hard coral cover. Out of a total of 57 scleractinian coral genera observed during the study period, 24 were utilized by C. octofasciatus. All fish collected during the study (n?=?36) had >86 % nematocysts in their guts, supporting their classification as obligate corallivores. Based on the Strauss electivity index, C. octofasciatus displayed a preference for the coral genus Acropora at all depths, while preference for Fungia became more marked at greater depth. Both Acropora and Fungia were observed at high density at all sites, with Acropora density decreasing markedly with depth and Fungia density increasing. Bite rates showed an asymptotic relationship to Acropora density, levelling off between 15 and 20 bites/5 min. The existence of a strong relationship with live coral cover and the preference for specific genera such as Acropora designate C. octofasciatus as a potential bioindicator in the Thousand Islands reefs, while making it particular susceptible to the ongoing degradation of reefs in the region.  相似文献   

8.
Predation pressure on an individual may be influenced by spatial associations with other organisms. In the case of rare and imperiled species, such indirect interactions may affect the persistence and recovery of local populations. This study examined the effects of coral neighborhood composition on the foraging behavior and impact of the corallivorous gastropod, Coralliophila abbreviata. We conducted a manipulative field experiment in which focal colonies of the threatened scleractinian coral Acropora cervicornis had no neighbors, conspecific neighbors, alternative prey (Orbicella faveolata) neighbors, or non-prey (Porites asteroides) neighbors. Individually tagged C. abbreviata were then seeded into the study area and allowed to colonize the experimental plots. Initial colonization was significantly affected by the species of neighboring corals and snail abundance after colonization was negatively correlated with focal colony growth. Snails exhibited a strong prey preference for A. cervicornis over O. faveolata and responded numerically to neighborhood quality (i.e., relative preference for neighboring corals). Thus, conspecific neighbors had the greatest predator-mediated negative effect on focal colony performance followed by O. faveolata neighbors. The results suggest that C. abbreviata mediate apparent competition between O. faveolata and A. cervicornis as both species contributed to the local abundance of their shared predator. Additionally, home range estimates for tagged C. abbreviata were calculated, compared among sexes, and found to be significantly greater for males than for females. Overall, this study sheds light on the foraging behavior of an important coral predator and highlights the potential importance of consumer-mediated indirect interactions in the dynamics of severely reduced populations. The results also have direct implications for conservation and population enhancement efforts.  相似文献   

9.
This study examined the effects of colony size and polyp position on six variables of polyp fecundity [egg number, egg size, total egg volume, total testis volume, total gonad volume, and gonad ratio (egg volume/testis volume)] in three tabular Acropora corals (Scleractinia), A. hyacinthus, A. japonica, and A. solitaryensis. Samples were collected from various colony sizes (n = 21–30 colonies species?1), just before the predicted spawning at Kochi, Japan, in 2009. Five replicate polyps were sampled at three positions (center, middle, and outer) from the center to the marginal area in each tabular colony. Results indicated effects of colony size and polyp position on both male and female gonads polyp?1. A positive effect of colony size was observed on variables of female gonads polyp?1 (egg number, total egg volume) in A. hyacinthus only, while the positive effect on the variable of male gonads polyp?1 (total testis volume) was common in all Acropora species, with total testis volume polyp?1 increasing 2–4-fold from the small (200–400 cm2) to the large size class (5,000–9,000 cm2). Among the polyp positions, lower values were observed mostly in center polyps in A. hyacinthus, while lower values were observed only in outer polyps in the other Acropora species. The distinct patterns between A. hyacinthus and the other two Acropora species suggest different reproductive strategies at the species level. Further studies are needed to confirm the prevalence of these effects in scleractinian corals, which will broaden our understanding of reproductive life history strategies and improve the estimation of reproductive performance.  相似文献   

10.
Glyphosate (N-phosphonomethyl glycine) is registered as a herbicide for many food and non-food crops, as well as non-crop areas where total vegetation control is desired. Glyphosate influences the soil mycobiota; however, the possible effect of glyphosate residues in animal feed (soybean, corn, etc.) on animal mycobiota is almost unknown. Accordingly, the present study was initiated to investigate the mycological characteristics of dairy cows in relationship to glyphosate concentrations in urine. A total of 258 dairy cows on 14 dairy farms in Germany were examined. Glyphosate was detected in urine using ELISA. The fungal profile was analyzed in rumen fluid samples using conventional microbiological culture techniques and differentiated by MALDI-TOF mass spectrometry. LPS-binding protein (LBP) and antibodies (IgG1, IgG2, IgA, and IgM) against fungi were determined in blood using ELISA. Different populations of Lichtheimia corymbifera, Lichtheimia ramosa, Mucor, and Rhizopus were detected. L. corymbifera and L. ramosa were significantly more abundant in animals containing high glyphosate (>40 ng/ml) concentrations in urine. There were no significant changes in IgG1 and IgG2 antibodies toward isolated fungi that were related to glyphosate concentration in urine; however, IgA antibodies against L. corymbifera and L. ramosa were significantly lower in the higher glyphosate groups. Moreover, a negative correlation between IgM antibodies against L. corymbifera, L. ramosa, and Rhizopus relative to glyphosate concentration in urine was observed. LBP also was significantly decreased in animals with higher concentrations of glyphosate in their urine. In conclusion, glyphosate appears to modulate the fungal community. The reduction of IgM antibodies and LBP indicates an influence on the innate immune system of animals.  相似文献   

11.
Four new species and one new variety of Rubiaceae from French Guiana are described:Psychotria alloantha, P. cypellantha, P. squamelligera, P. viridibractea, andSipanea ovalifolia var.villosissima.  相似文献   

12.
Pseudomonad bacterial are a phylogenetically diverse assemblage of species named within contemporary genera that includePseudomonas, Xanthomonas andAlcaligenes. Thus far, five distinct rRNA homology groups (Groups I through V) have been established by oligonucleotide cataloging and by rRNA/DNA hybridization. A pattern of enzymic features of aromatic amino acid biosynthesis (enzymological patterning) is conserved at the level of rRNA homology, five distinct and unambiguous patterns therefore existing in correspondence with the rRNA homology groups. We sorted 87 pseudomonad strains into Groups (and Subgroups) by aromatic pathway patterning. The reliability of this methodology was tested in a blind study using coded cultures of diverse pseudomonad organisms provided by American Type Culture Collection. Fourteen of 14 correct assignments were made at the Group level (the level of rRNA homology), and 12 of 14 correct assignments were made at the finer-tuned Subgroup levels. Many strains of unknown rRNA-homology affiliation had been placed into tentative rRNA groupings based upon enzymological patterning. Positive confirmation of such strains as members of the predicted rRNA homology groups was demonstrated by DNA/rRNA hybridization in nearly every case. It seems clear that the combination of these molecular approaches will make it feasible to deduce the evolution of biochemical-pathway construction and regulation in parallel with the emerging phylogenies of microbes housing these pathways.  相似文献   

13.
Collections from French Guiana, Amazonian Brazil, and Colombia taken in the last 20 years include new species in the following genera:Duroia, Pagamea, Psychotria, Randia, Retiniphyllum, Rudgea, Sabicea, Sipanea, andSphinctanthus. Twenty-one new species are described and five are illustrated.  相似文献   

14.

Background and aims

Paenibacillus spp. are widely considered to impact the fertility and health of soil. The aim of this study was to evaluate how different fertilization regimes affect the population size and community structure of Paenibacillus spp. over a long period of time in red soil.

Methods

Soil samples were collected from a long-term experiment and were then analyzed using real-time PCR and PCR-DGGE. The correlation analysis, PCA and RDA were used to explore the relationships among Paenibacillus spp. population, community structure and soil properties in different treatments.

Results

The pH was seriously decreased only by the application of chemical fertilizer. The largest population of Paenibacillus spp. was found in the soil treated with organic fertilizer application, while the richest diversity was observed in the soil treated only with the chemical fertilizer. The Paenibacillus spp., Paenibacillus alkaliterrae, Paenibacillus campinasensis, and Paenibacillus xylanilyticus were found in all treatments. Paenibacillus castaneae was found in the soil treated with NPK, and Paenibacillus pabuli was specifically observed in the lime-amended treatment. Paenibacillus taichungensis and Paenibacillus prosopidis were detected in the soil treated with only chemical fertilizer. Except for the ammonium and pH, all the tested soil fertility parameters (total C, total N, nitrate, available K and available P) could significantly affect both the Paenibacillus spp. population number and diversity. The soil pH was significantly correlated with Paenibacillus spp. diversity only.

Conclusions

Our results indicate that the different long-term fertilization regimes have varied impact on both the Paenibacillus spp. population size and the diversity of the community associated with the soil properties tested. These results can help to enrich the information on the response of beneficial soil microbes to different long-term fertilization regimes.  相似文献   

15.
Severe protein-calorie malnutrition is common in patients with AIDS and could contribute to the progressive deterioration characteristic of that disease. Selenium deficiency could also have a negative impact on immune function and other organ functions vital for recovery from infectious diseases. Therefore, to assess any role for selenium in AIDS, we determined plasma and erythrocyte selenium levels and glutathione peroxidase activity in 13 patients with AIDS compared to 8 patients with AIDS-related complex (ARC) and 14 healthy controls. Plasma selenium levels were significantly reduced in AIDS patients compared to controls (p<.0001) and to ARC (p<.02). Erythrocyte selenium levels in both AIDS and ARC were also reduced compared to controls (p<.02), but not to each other. Glutathione peroxidase activity in AIDS was 28.9±1.4 U/g Hb vs 38.4±6.9 in ARC (p=NS) and 52.3±1.7 in controls (p<.0001 vs AIDS;p<.02 vs ARC). When all groups were combined, there were significant correlations between total lymphocyte count and both plasma selenium (r=.53;p<.002) and erythrocyte glutathione peroxidase activity (r=.65;p<.0001). In addition, strong correlations were noted between plasma selenium and serum albumin (r=.68;p<.0001), plasma selenium and glutathione peroxidase (r=.77;p<.0001), and glutathione peroxidase and hematocrit (r=.66;p<.0001). In AIDS or ARC, no correlations between selenium with disease duration or weight loss were present. We conclude that, in comparison to normals, patients manifesting infection with human immunodeficiency virus have evidence of selenium deficiency as determined by diminished plasma and erythrocyte levels and glutathione peroxidase activity. These abnormalities are most marked in patients with AIDS, but are also present in patients with AIDS-related complex. Selenium deficiency has important implications for the progression and pathogenesis of clinical disease in AIDS.  相似文献   

16.
The syntheses of two potential cAMP affinity lables, 1,N 6-(3-iodopropyleno)adenosine 3′,5′-cyclic-monophosphate and 2′-O-(2-iodo-3-hydroxypropyl) adenosine 3′,5′-cyclic-monophosphate, by a two-step chemical procedure are described. TheN 6- and 2′-O-allyl intermediates were prepared selectively by alkylation of cAMP in organic and alkaline aqueous solutions, respectively. Treatment of theN 6-allyl derivative withN-iodosuccinimide resulted in iodine addition to the double bond and cyclization to theN 1 position of the purine ring. The iodohydrin analog was synthesized by reaction of 2′-O-allyl-cAMP with potassium iodide and thallium trichloride in acetate buffered solution. The products were isolated by column chromatography and characterized by thin-layer chromatography, elemental analysis, and ultraviolet,13C, and1H NMR spectroscopy. The cAMP analogs were found to react with lysine and cysteine. Both cAMP derivatives were tested for their reaction with the low-K m cAMP phosphodiesterase of human platelets. The ribose-substituted analog functioned as a competitive inhibitor (K I =0.72 μM) and caused a time-dependent irreversible inactivation of the phosphodiesterase. In contrast, the purine-substituted derivative acted neither as a reversible competitive inhibitor nor as an irreversible inactivator of the enzyme. These results indicate the specificity of these potential cAMP analogs in their interaction with the phosphodiesterase.  相似文献   

17.
Successful independent replication is the most direct approach for distinguishing real genotype–disease associations from false discoveries in genome-wide association studies (GWAS). Selecting SNPs for replication has been primarily based on P values from the discovery stage, although additional characteristics of SNPs may be used to improve replication success. We used disease-associated SNPs from more than 2,000 published GWASs to identify predictors of SNP reproducibility. SNP reproducibility was defined as a proportion of successful replications among all replication attempts. The study reporting association for the first time was considered to be discovery and all consequent studies targeting the same phenotype replications. We found that ?Log(P), where P is a P value from the discovery study, is the strongest predictor of the SNP reproducibility. Other significant predictors include type of the SNP (e.g., missense vs intronic SNPs) and minor allele frequency. Features of the genes linked to the disease-associated SNP also predict SNP reproducibility. Based on empirically defined rules, we developed a reproducibility score (RS) to predict SNP reproducibility independently of ?Log(P). We used data from two lung cancer GWAS studies as well as recently reported disease-associated SNPs to validate RS. Minus Log(P) outperforms RS when the very top SNPs are selected, while RS works better with relaxed selection criteria. In conclusion, we propose an empirical model to predict SNP reproducibility, which can be used to select SNPs for validation and prioritization.  相似文献   

18.
(Na++K+)-ATPase proved to be present in the vegetative thalli ofBoergesenia forbesii (Harvey) Feldmann. The ATPase was extracted with Triton X-100 and partially purified by Sephadex G-150 gel filtration. The enzyme was activated with Mg2+ and further stimulated by the addition of K+ and Na+. It was observed thatp-chloromercuribenzoate (PCMB),N-ethylmaleimide (NEM), iodoacetoamide, copper sulfate, zinc sulfate, lead nitrate and cadmium chloride inhibited the enzyme activity, but ouabain was ineffective, andN,N′-dicyclohexylcarbodiimide (DCCD) did not apparently inhibit the activity, but rather promoted it slightly. The ATPase activity was also shown in the isolated cell wall ofBoergesenia thalli, and the enzyme activity was detected in the wall itself by using electron microscopic methods.  相似文献   

19.
To more effectively control two major cotton insects (cotton bollworm and Spodoptera litura) and improve the efficacy of the pest resistance management, novel transgenic plants expressing Bacillus thuringiensis Cry9C gene were generated, and gene stacking strategy was incorporated. Initially, a binary plasmid vector harboring Cry9C gene was introduced into an elite cotton cultivar Simian-3 by Agrobacterium-mediated transformation. Integration and expression of the Cry9C genes in three transgenic lines were confirmed by PCR and RT-PCR. Among these transgenic lines, T0 generation of line 16 (L-16) with normal phenotypes were selected by ELISA assays for its highest expression level of Cry9C. In T1 population of L-16, the expression level of Cry9C ranged from 29 to 45 μg/g fresh leaf. The following insect bioassays demonstrated that transgenic S3-35S::Cry9C cotton plants exhibited moderate toxicity to Heliothis armigera but strong toxicity to S. litura compared with the transgenic plants expressing Cry 1Ac gene. For incorporation of gene staking strategy, Cry9C gene and Cry 2A or Cry 1Ac were pyramided, respectively by sexual crossing. The expression of Cry9C protein in all F1 progenies had a similar level as the parent plants indicating the high heritability of Bt genes in transgenic progenies. Progenies from both Cry9C × Cry 2A and Cry9C × Cry 1Ac exhibited higher resistance to S. litura compared with their parents. Together our data demonstrated that our newly generated transgenic plants represent a reservoir of novel insect-resistant materials in cotton breeding, and the successful incorporation of gene pyramiding technology can provide a new solution of developing multiple resistance management strategies.  相似文献   

20.
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