Bacterial Community Response to Petroleum Hydrocarbon Amendments in Freshwater,Marine, and Hypersaline Water-Containing Microcosms

Hydrocarbon-degrading bacterial communities from freshwater, marine, and hypersaline Brazilian aquatic ecosystems (with water salinities corresponding to 0.2%, 4%, and 5%, respectively) were enriched with different hydrocarbons (heptadecane, naphthalene, or crude oil). Changes within the different microcosms of bacterial communities were analyzed using cultivation approaches and molecular methods (DNA and RNA extraction, followed by genetic fingerprinting and analyses of clone libraries based on the 16S rRNA-coding gene). A redundancy analysis (RDA) of the genetic fingerprint data and a principal component analysis (PCA) of the clone libraries revealed hydrocarbon-enriched bacterial communities specific for each ecosystem studied. However, within the same ecosystem, different bacterial communities were selected according to the petroleum hydrocarbon used. In general, the results demonstrated that Acinetobacter and Cloacibacterium were the dominant genera in freshwater microcosms; the Oceanospirillales order and the Marinobacter, Pseudomonas, and Cycloclasticus genera predominated in marine microcosms; and the Oceanospirillales order and the Marinobacter genus were selected in the different hydrocarbon-containing microcosms in hypersaline water. Determination of total petroleum hydrocarbons (TPHs) in all microcosms after 32 days of incubation showed a decrease in the hydrocarbon concentration compared to that for the controls. A total of 50 (41.3%) isolates from the different hydrocarbon-contaminated microcosms were associated with the dominant operational taxonomic units (OTUs) obtained from the clone libraries, and their growth in the hydrocarbon contaminating the microcosm from which they were isolated as the sole carbon source was observed. These data provide insight into the general response of bacterial communities from freshwater, marine, and hypersaline aquatic ecosystems to petroleum hydrocarbon contamination.     

Identification of HIV-1 nucleocapsid protein: nucleic acid antagonists with cellular anti-HIV activity

The crucial functions of HIV-1 nucleocapsid-p7 protein (NC-p7) at different stages of HIV replication are dependent on its nucleic acid binding properties. In this study, a search has been made to identify antagonists of the interaction between NC-p7 and d(TG)(4). A chemical library of approximately 2000 small molecules (the NCI Diversity Set) was screened, of the 26 active inhibitors that were identified, five contained a xanthenyl ring structure. Further analysis of 63 structurally related compounds led to the identification of 2,3,4,5-tetrachloro-6-(4('),5('),6(')-trihydroxy-3(')-oxo-3H-xanthen-9(')-yl)benzoic acid, which binds to NC-p7 stoichiometrically. This compound exerted a significant anti-HIV activity in vitro with an IC(50) of 16.6+/-4.3 microM (means+/-SD). Synthetic variants lacking the two hydroxyls at positions 4(') and 5(') in the xanthenyl ring system failed to bind NC-p7 and showed significantly less protection against HIV infection. Molecular modeling predicts that these hydroxyl groups would bind to the amide nitrogen of Gly(35) with other contacts at the carbonyl oxygens of Gly(40) and Lys(33).     

Biological control on gastrointestinal nematodes in cattle with association of nematophagous fungi

This study aimed to evaluate the efficacy of the association of the nematophagous fungi (Duddingtonia flagrans-AC001); (Pochonia chlamydosporia-VC4) and (Arthrobotrys robusta-I31) in a pelletised formulation of a sodium alginate matrix. The viability and activity of pellet germination and fungal activity (after encapsulation) were evaluated using in vitro and in vivo tests. Next, 12 heads of cattle, Dutch mestizo x zebu, with an average age of 12 months were dewormed with an anthelmintic. Next, 20 days after treatment with the anthelmintic, the animals were randomly divided into two groups of six animals each, and placed in two paddocks with 7.0?ha each of Brachiaria decumbens with historical grazing by animals naturally infected by gastrointestinal nematode parasites. At first, each animal was treated with 2?g of pellets per 10?kg of animal, containing the associated fungi (AC001?+?VC4?+?I31) administered twice a week in conjunction with commercial feed. Each animal in the control group received 2?g of pellets without mycelia added to the feed. The percentage reduction of infective larvae in the in vitro test was 94% (p?in vivo test, the treated animals with fungal association had lower egg counts per gram of faeces (p?相似文献   

AAV-mediated gene delivery in adult GM1-gangliosidosis mice corrects lysosomal storage in CNS and improves survival

Background

GM1-gangliosidosis is a glycosphingolipid (GSL) lysosomal storage disease caused by a genetic deficiency of acid β-galactosidase (βgal), which results in the accumulation of GM1-ganglioside and its asialo-form (GA1) primarily in the CNS. Age of onset ranges from infancy to adulthood, and excessive ganglioside accumulation produces progressive neurodegeneration and psychomotor retardation in humans. Currently, there are no effective therapies for the treatment of GM1-gangliosidosis.

Methodology/Principal Findings

In this study we examined the effect of thalamic infusion of AAV2/1-βgal vector in adult GM1 mice on enzyme distribution, activity, and GSL content in the CNS, motor behavior, and survival. Six to eight week-old GM1 mice received bilateral injections of AAV vector in the thalamus, or thalamus and deep cerebellar nuclei (DCN) with pre-determined endpoints at 1 and 4 months post-injection, and the humane endpoint, or 52 weeks of age. Enzyme activity was elevated throughout the CNS of AAV-treated GM1 mice and GSL storage nearly normalized in most structures analyzed, except in the spinal cord which showed ∼50% reduction compared to age-matched untreated GM1 mice spinal cord. Survival was significantly longer in AAV-treated GM1 mice (52 wks) than in untreated mice. However the motor performance of AAV-treated GM1 mice declined over time at a rate similar to that observed in untreated GM1 mice.

Conclusions/Significance

Our studies show that the AAV-modified thalamus can be used as a ‘built-in’ central node network for widespread distribution of lysosomal enzymes in the mouse cerebrum. In addition, this study indicates that thalamic delivery of AAV vectors should be combined with additional targets to supply the cerebellum and spinal cord with therapeutic levels of enzyme necessary to achieve complete correction of the neurological phenotype in GM1 mice.     

Differential regulation of a MYB transcription factor is correlated with transgenerational epigenetic inheritance of trichome density in Mimulus guttatus

? Epigenetic inheritance, transgenerational transmission of traits not proximally determined by DNA sequence, has been linked to transmission of chromatin modifications and gene regulation, which are known to be sensitive to environmental factors. Mimulus guttatus increases trichome (plant hair) density in response to simulated herbivore damage. Increased density is expressed in progeny even if progeny do not experience damage. To better understand epigenetic inheritance of trichome production, we tested the hypothesis that candidate gene expression states are inherited in response to parental damage. ? Using M. guttatus recombinant inbred lines, offspring of leaf-damaged and control plants were raised without damage. Relative expression of candidate trichome development genes was measured in offspring. Line and parental damage effects on trichome density were measured. Associations between gene expression, trichome density, and response to parental damage were determined. ? We identified M. guttatus MYB MIXTA-like 8 as a possible negative regulator of trichome development. We found that parental leaf damage induces down-regulation of MYB MIXTA-like 8 in progeny, which is associated with epigenetically inherited increased trichome density. ? Our results link epigenetic transmission of an ecologically important trait with differential gene expression states - providing insight into a mechanism underlying environmentally induced 'soft inheritance'.     

Presence and seasonal prevalence of Plasmodium spp. in a rare endemic New Zealand passerine (tieke or Saddleback, Philesturnus carunculatus)

The conservation and management of Saddlebacks (Philesturnus carunculatus) and other New Zealand birds, currently relies on the translocation of individuals to predator-free sites. Avian malaria has been identified as one of the diseases to be tested for prior to translocations in New Zealand, with the aim of translocating disease-free individuals. We describe avian malaria lineages and their seasonal prevalence in 2007-2008 in Saddlebacks from Mokoia Island, a source of birds for translocations, and investigate their pathogenicity. Three lineages of avian malaria were found at low prevalence (≤10.6%) and parasitemia (all but one infection were below 1/10,000 erythrocytes), typical of chronic infections. Two lineages clustered with previously identified lineages of Plasmodium relictum and one with a lineage of Plasmodium (Huffia) elongatum. Prevalence of malaria infection was higher in the spring with no significant difference in prevalence between juvenile and adult birds. We found no effect of stress on infections or any indication of pathogenicity.     

Evolution of petaloid sepals independent of shifts in B-class MADS box gene expression

Attractive petals are an integral component of animal-pollinated flowers and in many flowering plant species are restricted to the second floral whorl. Interestingly, multiple times during angiosperm evolution, petaloid characteristics have expanded to adjacent floral whorls or to extra-floral organs. Here, we investigate developmental characteristics of petaloid sepals in Rhodochiton atrosanguineum, a close relative of the model species Antirrhinum majus (snapdragon). We undertook this in two ways, first using scanning electron microscopy we investigate the micromorphology of petals and sepals, followed by expression studies of genes usually responsible for the formation of petaloid structures. From our data, we conclude that R. atrosanguineum petaloid sepals lack micromorphological characteristics of petals and that petaloid sepals did not evolve through regulatory evolution of B-class MADS box genes, which have been shown to specify second whorl petal identity in a number of model flowering plant species including snapdragon. These data, in conjunction with other studies, suggests multiple convergent pathways for the evolution of showy sepals.     

What free‐ranging animals do at the zoo: a study of the behavior and habitat use of opossums (Didelphis virginiana) on the grounds of the St. Louis Zoo

Studies of urban wildlife are important because they can give us insight into both how animals adapt to novel environments and how some species survive and prosper in human‐dominated landscapes. Urban zoological institutions provide an ideal setting for research on such species. We report on a study of the behavior and ecology of opossums (Didelphis virginiana) on the grounds of the St. Louis Zoological Park. We used radio tracking to investigate the movement patterns and den site use of opossums on the grounds of the zoo and compared the results to data available for opossums elsewhere. We find that urban opossums in the St. Louis zoo have smaller home ranges and move shorter distances than their rural counterparts. We suggest that increased food availability and decreased risk of predation might explain such differences, and we suspect that conditions are even more favorable to opossums in a zoological setting than in cities in general. Our findings illustrate that there is much to be learned from scientific study of the free‐living animals found on zoological park grounds. Zoo Biol 00:1–17, 2005. © 2005 Wiley‐Liss, Inc.