Project description:Comparison of probe-target dissociations of probe Eub338 and Gam42a with native RNA of P. putida, in vitro transcribed 16s rRNA of P. putida, in vitro transcribed 16S rRNA of a 2,4,6-trinitrotoluene contaminated soil and an uncontaminated soil sample. Functional ANOVA revealed no significant differences in the dissociation curves of probe Eub338 when hybridised to the different samples. On the opposite, the dissociation curve of probe Gam42a with native RNA of P. putida was significantly different than the dissociation curves obtained with in vitro transcribed 16S rRNA samples. Keywords: Microbial diversity, thermal dissociation analysis, CodeLink microarray
Project description:Antimony (Sb) pollution, especially released from mining activities has already been widely recognized as a global concern. To gauge strategies for the remediation of an Sb-contaminated ecosystem, the exploration of native microbiota Sb(III) resistance mechanism is of great significance. Acinetobacter is one of the bacterial genera abundantly thriving in Sb(III)-contaminated environments, the scientific elaboration of Sb(III)-resistance mechanisms of Acinetobacter is imperative. Proteomics experiment was performed (Acinetobacter johnsonii JH7 with and without Sb(III) addtion) to probe its pattern of proteins change under Sb(III) stress. We hope that the mechanisms of Sb(III) resistance of Acinetobacter could be revealed by using iTRAQ this time.
Project description:The survival, pollutant degradation activity and transcriptome response was monitored in Sphingomonas sp. LH128 inoculated into soil. Cultivable cell numbers were determined by plating, while phenanthrene degradation was monitored by HPLC. The genetic base for the adaptive strategy of LH128 in soil was investigated by using microarray consisting 7,200 gene-coding ORFs. During 4 hours of incubation, 510 genes were differentially expressed (317 increased and 193 reduced expression) while 610 genes were differentially expressed (318 increased and 292 reduced) after 10 days of incubation. Genes with increased expression comprised of gene encoding PAH catabolic enzymes, stress resistance, oxidative stress tolerance, outer membrane proteins/porins and efflux pump proteins while the downregulated genes comprised of genes encoding flagellar biosynthesis, ribosomal proteins and ATPase. Transcriptomic response of phenanthrene degrading Sphingomonas sp. LH128 inoculated into phenanthrene contaminated soil after 4h and after 10 days of incubation was studied using genome-wide gene expression analysis. For this purpose, the strain was pregrown in minimal medium and inoculated at appropriated celld densitites. RNA was extracted both from soil and and from initial inoculum and cDNA was synthesized and labeled with Cy3. Transcriptomic response in soil of three replicates per conditions after both incubation duration were analyzed and compared with the initial inoculum
Project description:Microbial community analysis with DNA oligonucleotide microarrays targeting ribosomal RNA (rRNA) provides a highly parallel interrogation of nucleic acids isolated from environmental samples. High fidelity readout is essential for accurate interpretation of hybridisations. We describe the hybridisation of in vitro transcribed 16S rRNA from an uncontaminated and 2,4,6-trinitrotoluene contaminated soil to an oligonucleotide microarray containing group- and species-specific perfect match (PM) probes and their 2 corresponding mismatch (MM) probes. Thermal dissociation analysis was used to determine the specificity of each PM-MM probe set. Functional ANOVA often discriminated PM-MM probe sets when Td values (temperature at 50% probe-target dissociation) could not. Maximum discrimination for many PM and MM probes often occurred at temperatures greater than the Td. Comparison of signal intensities measured prior to dissociation analysis from hybridisations of the two soil samples revealed significant differences in domain-, group- and species-specific probes. Functional ANOVA showed significantly different dissociation curves for 11 PM probes when hybridisations from the two soil samples were compared, even though initial signal intensities for 3 of the 11 did not vary. This approach provides a highly parallel, multi-level analysis that incorporates MM probes and dissociation curves into high fidelity microarray analysis of complex environmental nucleic acid profiles. Keywords: Microbial diversity, thermal dissociation analysis
Project description:In the fire ant Solenopsis invicta, a colony queen number is determined by the founding queen's genotypes at the 13 Mb supergene with the non-recombining variants SB and Sb. Single-queen colonies are always headed by SB/SB queens while multiple-queens colonies are always headed by SB/Sb queens. The two variants of the supergene, SB and Sb are completely linked to the two alleles (B and b) of the gene Gp-9. SB/SB and SB/Sb queens differ in many physiological traits including their maturation rate and odor. To explain why SB/SB and SB/Sb queens have different odors, and why SB/SB virgins mature faster and accumulate more fat, we measured expression of ~6000 genes in virgin queens 1 and 11 days after eclosion and in reproductive queens. Keywords: fire ants, Solenopsis invicta, Supergene, queen, Gp-9, social form, maturation, fat storage, queen odor, cuticular hydrocarbon, worker discrimination, monogyne, polygyne, transposon, chemical signaling