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91.
Aporrectodea caliginosa is the most common endogeic (topsoil) earthworm in New Zealand and, because of its habitat, is potentially vulnerable to surface-applied pesticides. Lysosomal damage to earthworms, which can be visualized by the use of the neutral red retention assay (NRRA) has been evaluated in this species as a biomarker of organophosphate exposure. Earthworms were exposed in the laboratory to sub-lethal concentrations of chlorpyrifos and diazinon. In a semi-field experiment, earthworms were placed in mesocosms in a field sprayed with these pesticides at the rate recommended for a vegetable crop. In the laboratory, the neutral red retention time (NRRT) was significantly reduced following exposure to both pesticides compared with controls. In the semi-field experiment, earthworm NRRT was significantly reduced by both pesticides. These experiments have shown that the NRRA is very sensitive to exposure to chlorpyrifos and diazinon even at field rates. It therefore shows promise as a potential biomarker of contamination of soil by organophosphates. 相似文献
92.
El-Sayed NM Ghedin E Song J MacLeod A Bringaud F Larkin C Wanless D Peterson J Hou L Taylor S Tweedie A Biteau N Khalak HG Lin X Mason T Hannick L Caler E Blandin G Bartholomeu D Simpson AJ Kaul S Zhao H Pai G Van Aken S Utterback T Haas B Koo HL Umayam L Suh B Gerrard C Leech V Qi R Zhou S Schwartz D Feldblyum T Salzberg S Tait A Turner CM Ullu E White O Melville S Adams MD Fraser CM Donelson JE 《Nucleic acids research》2003,31(16):4856-4863
93.
Geographical Distribution and Diversity of Bacteria Associated with Natural Populations of Drosophila melanogaster 下载免费PDF全文
Vanessa Corby-Harris Ana Clara Pontaroli Lawrence J. Shimkets Jeffrey L. Bennetzen Kristin E. Habel Daniel E. L. Promislow 《Applied microbiology》2007,73(11):3470-3479
Drosophila melanogaster is one of the most widely used model systems in biology. However, little is known about its associated bacterial community. As a first step towards understanding these communities, we compared bacterial 16S rRNA gene sequence libraries recovered from 11 natural populations of adult D. melanogaster. Bacteria from these sequence libraries were grouped into 74 distinct taxa, spanning the phyla Proteobacteria, Bacteroidetes, and Firmicutes, which were unevenly spread across host populations. Summed across populations, the distribution of abundance of genera was closely fit by a power law. We observed differences among host population locations both in bacterial community richness and in composition. Despite this significant spatial variation, no relationship was observed between species richness and a variety of abiotic factors, such as temperature and latitude. Overall, bacterial communities associated with adult D. melanogaster hosts are diverse and differ across host populations. 相似文献
94.
Vanessa Cristine Sousa de Moraes Paula Baloni Andrade Edi Lúcia Sartorato 《Biochemical and biophysical research communications》2009,381(2):210-848
Hearing impairment is the most prevalent sensorial deficit in the general population. Congenital deafness occurs in about 1 in 1000 live births, of which approximately 50% has hereditary cause in development countries. Non-syndromic deafness can be caused by mutations in both nuclear and mitochondrial genes. Mutations in mtDNA have been associated with aminoglycoside-induced and non-syndromic deafness in many families worldwide. However, the nuclear background influences the phenotypic expression of these pathogenic mutations. Indeed, it has been proposed that nuclear modifier genes modulate the phenotypic manifestation of the mitochondrial A1555G mutation in the MTRNR1 gene. The both putative nuclear modifiers genes TRMU and MTO1 encoding a highly conserved mitochondrial related to tRNA modification. It has been hypothesizes that human TRMU and also MTO1 nuclear genes may modulate the phenotypic manifestation of deafness-associated mitochondrial mutations. The aim of this work was to elucidate the contribution of mitochondrial mutations, nuclear modifier genes mutations and aminoglycoside exposure in the deafness phenotype. Our findings suggest that the genetic background of individuals may play an important role in the pathogenesis of deafness-associated with mitochondrial mutation and aminoglycoside-induced. 相似文献
95.
Diel variation of phytoplankton functional groups in a subtropical reservoir in southern Brazil during an autumnal stratification period 总被引:1,自引:0,他引:1
A knowledge of diel variation and the vertical distribution of phytoplankton communities may contribute to a better understanding
of the driving factors of key species. Applying functional-group classification provides important information on the causes
of species selection in the pelagic community. The diel variation of phytoplankton functional groups was analysed during an
autumnal stratification period with the aim of understanding their changes in the vertical position related to light, mixing
regime and grazing pressure. Phytoplankton and zooplankton communities were sampled every 4 h during a 24-h period in a vertical
profile in a subtropical meso-eutrophic reservoir. Strong stratification during a 24-h cycle and a mixed clear epilimnion
with partial atelomixis marked the autumn season in the Faxinal reservoir, southern Brazil. The highest phytoplankton densities
and biomass were found during the second part of the day, a general pattern reported in the literature, and may be explained
by zooplankton dynamics. During the 24-h cycle, phytoplankton functional groups lacking a self-regulating capacity and those
able to regulate their vertical position were vertically segregated in the lake. The diel behaviour of both groups was driven
by the mixing regime (including atelomixis), light and zooplankton grazing pressure. 相似文献
96.
A deletion at the mouse Xist gene exposes trans-effects that alter the heterochromatin of the inactive X chromosome and the replication time and DNA stability of both X chromosomes 下载免费PDF全文
Diaz-Perez SV Ferguson DO Wang C Csankovszki G Wang C Tsai SC Dutta D Perez V Kim S Eller CD Salstrom J Ouyang Y Teitell MA Kaltenboeck B Chess A Huang S Marahrens Y 《Genetics》2006,174(3):1115-1133
The inactive X chromosome of female mammals displays several properties of heterochromatin including late replication, histone H4 hypoacetylation, histone H3 hypomethylation at lysine-4, and methylated CpG islands. We show that cre-Lox-mediated excision of 21 kb from both Xist alleles in female mouse fibroblasts led to the appearance of two histone modifications throughout the inactive X chromosome usually associated with euchromatin: histone H4 acetylation and histone H3 lysine-4 methylation. Despite these euchromatic properties, the inactive X chromosome was replicated even later in S phase than in wild-type female cells. Homozygosity for the deletion also caused regions of the active X chromosome that are associated with very high concentrations of LINE-1 elements to be replicated very late in S phase. Extreme late replication is a property of fragile sites and the 21-kb deletions destabilized the DNA of both X chromosomes, leading to deletions and translocations. This was accompanied by the phosphorylation of p53 at serine-15, an event that occurs in response to DNA damage, and the accumulation of gamma-H2AX, a histone involved in DNA repair, on the X chromosome. The Xist locus therefore maintains the DNA stability of both X chromosomes. 相似文献
97.
Raychaudhuri S Fontanes V Banerjee R Bernavichute Y Dasgupta A 《Biochemical and biophysical research communications》2006,350(3):788-795
A small inhibitor RNA (IRNA) isolated from yeast has previously been shown to efficiently block poliovirus and hepatitis C virus IRES-mediated translation by sequestering mammalian RNA-binding (transacting) factors that play important roles in cap-independent translation. Here we have investigated the IRNA-binding proteins that might be involved in cap-independent translation in the yeast Saccharomyces cerevisiae. We have identified Zuotin, a DnaJ chaperone protein similar to mammalian HSP-40 chaperone, which interacts strongly with IRNA. Using ZUO1-deleted S. cerevisiae, we demonstrate a preferential requirement of Zuo1p for cap-independent translation mediated by the 5' untranslated region of the yeast TFIID mRNA. Further studies using zuo1delta S. cerevisiae complemented with various Zuo1p mutants indicate that the DnaJ domain of Zuo1p, known to influence its interaction with HSP-70, significantly affects cap-independent translation. These results demonstrate for the first time a role for an established chaperone protein in cap-independent translation of a cellular mRNA. 相似文献
98.
Vanderley Rayane F. Ger Kemal A. Becker Vanessa Bezerra Maria Gabriela T. A. Panosso Renata 《Hydrobiologia》2021,848(4):943-960
Hydrobiologia - While warming and eutrophication have increased the frequency and magnitude of harmful cyanobacterial blooms globally, the scenario for many eutrophic tropical freshwaters is a... 相似文献
99.
Alice Toso Simona Schifano Charlotte Oxborough Krista McGrath Luke Spindler Anabela Castro Lucy Evangelista Vanessa Filipe Maria José Gonçalves Antonio Marques Inês Mendes da Silva Raquel Santos Maria João Valente Iona McCleery Michelle Alexander 《American journal of physical anthropology》2021,176(2):208-222
100.
In this work, spray-dried lipid systems based on soy phosphatidylcholine, cholesterol and lauroyl polyoxylglycerides for entrapping Green tea polyphenols were produced. The aim was to study the effects of the encapsulating composition and spray drying conditions on the system performance and physicochemical product properties. The spray dryer powder production yield falls around 50.7?±?2.8%, which is typical for lab scale spray dryers. Wrinkled and rounded particles, with low surface porosities were generated, independent of the drying carriers (trehalose or lactose) used. The product showed high encapsulation efficiency of Green tea polyphenols, which was promptly redispersible in water. It presented low density, and good compressive and flow properties. The results herein reported confirm the feasibility of the entrapment of Green tea polyphenols in lipid-based compositions by spray drying in presence of the drying carriers evaluated. The spray-dried microparticles show high potential to be used as additive in food, nutraceutical and pharmaceutical products. 相似文献