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Highest Homology (highest + homology)
Selected AbstractsNtSET1, a member of a newly identified subgroup of plant SET-domain-containing proteins, is chromatin-associated and its ectopic overexpression inhibits tobacco plant growthTHE PLANT JOURNAL, Issue 4 2001Wen-Hui Shen Summary The SET- and chromo-domains are recognized as signature motifs for proteins that contribute to epigenetic control of gene expression through effects on the regional organization of chromatin structure. This paper reports the identification of a novel subgroup of SET-domain-containing proteins in tobacco and Arabidopsis, which show highest homologies with the Drosophila position-effect-variegation repressor protein SU(VAR)3,9 and the yeast centromer silencing protein CLR4. The tobacco SET-domain-containing protein (NtSET1) was fused to the green fluorescence protein (GFP) that serves as a visual marker for localization of the recombinant protein in living cells. Whereas control GFP protein alone was uniformly dispersed within the nucleus and cytoplasm, the NtSET1-GFP fusion protein showed a non-uniform localization to multiple nuclear regions in interphase tobacco TBY2 cells. During mitosis, the NtSET1-GFP associated with condensed chromosomes with a non-random distribution. The NtSET1 thus appears to have distinct target regions in the plant chromatin. Overexpression of the NtSET1-GFP in transgenic tobacco inhibited plant growth, implicating the possible involvement of the NtSET1 in transcriptional repression of growth control genes through the formation of higher-order chromatin domains. [source] Phylogenetic reconstruction of Gram-positive organisms based on comparative sequence analysis of molecular chaperones from the ruminal microorganism Ruminococcus flavefaciens FD-1FEMS MICROBIOLOGY LETTERS, Issue 1 2003Dionysios A. Antonopoulos Abstract Primers designed on the basis of nucleotide sequences conserved in DnaK and GroEL from Gram-positive organisms were used to PCR amplify internal regions of the cognate genes from the anaerobic ruminal cellulolytic bacterium Ruminococcus flavefaciens FD-1. Genome walking was then utilized to elucidate the remainder of the sequences in addition to upstream and downstream regions. The full sequence of the gene encoding the GroES protein (groES) was found directly upstream from groEL. The deduced amino acid sequence of the groEL gene showed the highest homology with the amino acid sequence of the Clostridium thermocellum GroEL protein (72% amino acid identity). Similarly, translation of the groES nucleotide sequence showed highest homology to the C. thermocellum GroES protein (61% amino acid identity). Analysis of the upstream region of this chaperonin operon revealed a CIRCE regulatory element 45 bp upstream from the putative start of the groES ORF. The deduced amino acid sequence of the putative dnaK gene showed the highest homology with the amino acid sequence of the Clostridium acetobutylicum DnaK protein (68% amino acid identity). Phylogenetic analyses based on the translated sequences reiterate this relationship between R. flavefaciens and the Clostridia. However, when the nucleotide sequences of Gram-positive organisms are analyzed, a different topology occurs of the relationship between high- and low-G+C Gram-positive organisms to the 16S rRNA interpretation. [source] Aldehyde oxidase is coamplified with the World's most common Culex mosquito insecticide resistance-associated esterasesINSECT MOLECULAR BIOLOGY, Issue 1 2000J. Hemingway Abstract The evolution and spread of insecticide resistance is an important factor in human disease prevention and crop protection. The mosquito Culex quinquefasciatus is the main vector of the disease filariasis and a member of a species complex which is a common biting nuisance worldwide. The common insecticide resistance mechanism in this species involves germline amplification of the esterases est,21 and est,21. This amplification has arisen once and rapidly spread worldwide. Less common and more variable resistance phenotypes involve coamplification of est,3 and est,1, or individual amplification of a single est,1, different alleles of the same est, and est, gene loci. Est,21 and est,21 are on the same large fragment of amplified DNA (amplicon) 2.7 kb apart. We have now shown that this amplicon contains another full-length gene immediately 5, of est,21 which codes for a molybdenum-containing hydroxylase, with highest homology to aldehyde oxidase (AO) from other organisms. The full-length putative AO gene is not present on the est,3/est,1 or est,1 amplicons, but multiple truncated 5, ends of this gene are present around the presumed est,3/est,1 amplicon breakpoint. Polymerase chain reaction (PCR) analysis of insecticide-susceptible genomic DNA demonstrated that a different allele of the putative AO gene in its non-amplified form is immediately 5, of est,. The ,AO' gene on the est,21/est,21 amplicon is expressed and resistant insects have greater AO activity. This AO activity is sensitive to inhibition by an aldehyde-containing herbicide and pesticide. This enzyme may confer a selective advantage to these insects in the presence of insecticide, as AO in mammals is believed to be important in the detoxification process of several environmental pollutants. [source] Study of mRNA Expression by Real Time PCR of Cpkk1, Cpkk2 and Cpkk3, three MEKs of Cryphonectria parasitica, in Virus-free and Virus-infected Isogenic IsolatesJOURNAL OF PHYTOPATHOLOGY, Issue 6 2010Laura Rostagno Abstract Cpkk1 and Cpkk2 are two previously characterized Mitogen-activated protein kinase kinases (MEK) from Cryphonectria parasitica. For the characterization of the third MEK, primers designed to a conserved region of the known fungal MEK sequences were used in a PCR reaction to amplify genomic DNA from C. parasitica. The sequence of the resulting amplicon was compared to known sequences in the database using a Blast search. Results of the sequence comparison indicated that the initial fragment obtained encoded for a new MEK from C. parasitica, that had highest homology to Pbs2 from Saccharomyces cerevisiae. By inverse PCR we obtained a genomic fragment spanning the entire coding sequence of this MEK, which was named Cpkk3. The cDNA of Cpkk3 was obtained by compiling the sequences of RT-PCR products resulting from the amplification of purified mRNA. TaqManŽ Probes were designed to analyse the expression of Cpkk1, Cpkk2 and Cpkk3 mRNA through RT-Real Time PCR. This protocol allowed the expression of Cpkk3 to be successfully compared to the expression of Cpkk1 and Cpkk2, two previously cloned C. parasitica MEKs. No variation in expression was associated with the presence of a virus after 2 days of growth in standard conditions whereas an increase in the expression level of all the three MEKs was shown after 4 days of growth. [source] Comparative Analysis of Phytophthora infestans Induced Gene Expression in Potato Cultivars with Different Levels of ResistancePLANT BIOLOGY, Issue 6 2005B. Ros Abstract: Differential gene expression was analyzed after infection with Phytophthora infestans in six potato cultivars with different levels of resistance to late blight. To verify the infection of the potato leaflets, the amount of phytopathogen mRNA within the plant material was quantified by real-time quantitative PCR. The expression of 182 genes selected from two subtracted cDNA libraries was studied with cDNA array hybridization using RNA from non-infected and infected potato leaflets. Gene up- and down-regulation were clearly detectable in all cultivars 72 h post inoculation. Gene expression patterns in susceptible cultivars differed from those in potato varieties with a higher level of resistance. In general, a stronger gene induction was observed in the susceptible cultivars compared to the moderately to highly resistant potato varieties. Five genes with the highest homology to stress and/or defence-related genes were induced specifically in the susceptible cultivars. Four genes responded to pathogen attack independently of the level of resistance of the cultivar used, and three genes were repressed in infected tissue of most cultivars. Even in the absence of P. infestans infection, six genes showed higher expression levels in the somewhat resistant cultivars Bettina and Matilda. Possible reasons for the different levels of gene expression are discussed. [source] | ||||||||||