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Other Clones (other + clone)
Selected AbstractsNiche heterogeneity determines bacterial community structure in the termite gut (Reticulitermes santonensis)ENVIRONMENTAL MICROBIOLOGY, Issue 7 2005Hong Yang Summary Differences in microenvironment and interactions of microorganisms within and across habitat boundaries should influence structure and diversity of the microbial communities within an ecosystem. We tested this hypothesis using the well characterized gut tract of the European subterranean termite Reticulitermes santonensis as a model. By cloning and sequencing analysis and molecular fingerprinting (terminal restriction fragment length polymorphism), we characterized the bacterial microbiota in the major intestinal habitats , the midgut, the wall of the hindgut paunch, the hindgut fluid and the intestinal protozoa. The bacterial community was very diverse (> 200 ribotypes) and comprised representatives of several phyla, including Firmicutes (mainly clostridia, streptococci and Mycoplasmatales -related clones), Bacteroidetes, Spirochaetes and a number of Proteobacteria, all of which were unevenly distributed among the four habitats. The largest group of clones fell into the so-called Termite group 1 (TG-1) phylum, which has no cultivated representatives. The majority of the TG-1 clones were associated with the protozoa and formed two phylogenetically distinct clusters, which consisted exclusively of clones previously retrieved from the gut of this and other Reticulitermes species. Also the other clones represented lineages of microorganisms that were exclusively recovered from the intestinal tract of termites. The termite specificity of these lineages was underscored by the finding that the closest relatives of the bacterial clones obtained from R. santonensis were usually derived also from the most closely related termites. Overall, differences in diversity between the different gut habitats and the uneven distribution of individual phylotypes support conclusively that niche heterogeneity is a strong determinant of the structure and spatial organization of the microbial community in the termite gut. [source] A BAC contig of approximately 400 kb contains the classical class I major histocompatibility complex (MHC) genes of cattleINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 1 2002F. Di Palma Summary A cattle BAC library derived from an MHC homozygous animal was screened for MHC class I genes. This revealed at least nine class I-related genes in a contig spanning ~400 kb, and several additional genes on other clones. The three classical class I genes expressed on this haplotype (A14) were shown to be distributed over a region at most 212 kb apart. [source] Investigation of the genetic diversity among isolates of Salmonella enterica serovar Dublin from animals and humans from England, Wales and IrelandJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2002E. Liebana Aims: To assess the degree of genetic diversity among animal Salmonella Dublin UK isolates, and to compare it with the genetic diversity found among human isolates from the same time period. Methods and Results: One hundred isolates (50 human and 50 animal) were typed using plasmid profiling, XbaI-pulsed field gel electrophoresis (PFGE) and PstI- SphI ribotyping. Antimicrobial resistance data to 16 antibiotics was presented, and the presence of class-I integrons was investigated by real-time PCR. Seven different plasmid profiles, 19 ribotypes and 21 PFGE types were detected. A combination of the three methods allowed clear differentiation of 43 clones or strains. Eighteen isolates were resistant to at least one antimicrobial; five of them were multi-resistant and of these, only three presented class I integrons. Conclusions: Ribotyping data suggest the existence of at least three very different clonal lines; the same distribution in well-defined groups was not evident from the PFGE data. The existence of a variety of clones in both animals and humans has been demonstrated. A few prevalent clones seem to be widely disseminated among different animal species and show a diverse geographical and temporal distribution. The same clones were found in animals and humans, which may infer that both farm and pet animals may act as potential vehicles of infection for humans. Some other clones seem to be less widely distributed. Clustering analysis of genomic fingerprints of Salmonella Dublin and Salm. Enteritidis isolates confirms the existence of a close phylogenetic relationship between both serotypes. Significance and Impact of the Study: This paper describes the utility of a multiple genetic typing approach for Salm. Dublin. It gives useful information on clonal diversity among human and animal isolates. [source] Genotype and temperature influence pea aphid resistance to a fungal entomopathogenPHYSIOLOGICAL ENTOMOLOGY, Issue 2 2003David A. Stacey Abstract. The influence of temperature on life history traits of four Acyrthosiphon pisum clones was investigated, together with their resistance to one genotype of the fungal entomopathogen Erynia neoaphidis. There was no difference among aphid clones in development rate, but they did differ in fecundity. Both development rate and fecundity were influenced by temperature, but all clones showed similar responses to the changes in temperature (i.e. the interaction term was nonsignificant). However, there were significant differences among clones in susceptibility to the pathogen, and this was influenced by temperature. Furthermore, the clones differed in how temperature influenced susceptibility, with susceptibility rankings changing with temperature. Two clones showed changes in susceptibility which mirrored changes in the in vitro vegetative growth rate of E. neoaphidis at different temperatures, whereas two other clones differed considerably from this expected response. Such interactions between genotype and temperature may help maintain heritable variation in aphid susceptibility to fungal pathogen attack and have implications for our understanding of disease dynamics in natural populations. This study also highlights the difficulties of drawing conclusions about the efficacy of a biological control agent when only a restricted range of pest genotypes or environmental conditions are considered. [source] Characterization of novel sugarcane expressed sequence tag microsatellites and their comparison with genomic SSRsPLANT BREEDING, Issue 4 2006L. R. Pinto Abstract Microsatellites or simple sequence repeats (SSRs) are one of the most suitable markers for genome analysis as they have great potential to aid breeders to develop new improved sugarcane varieties. The development of SSR derived from expressed sequence tags (EST) opens new opportunities for genetic investigations at a functional level. In the present work, the polymorphism obtained with a subset of 51 EST,SSRs derived from sucest was compared with those generated by 50 genomic SSRs (gSSR) in terms of number of alleles, polymorphism information content, discrimination power and their ability to establish genetic relationships among 18 sugarcane clones including three Saccharum species (S. officinarum, S. barberi, S. sinense). The majority of EST,SSRs loci had four to six alleles in contrast to the seven to nine observed for the gSSRs loci. Approximately, 35% of the gSSRs had PIC values around 0.90 in contrast to 15% of the EST,SSRs. However, the mean discrimination power of the two types of SSR did not differ significantly as much as the average genetic similarity (GS) based on Dice coefficient. The correlation between GS of the two types of SSRs was high (r = 0.71/P = 0.99) and significant. Although differences were observed between dendrograms obtained with each SSR type, both were in good agreement with pedigree information. The S. officinarum clone IJ76-314 was grouped apart from the other clones evaluated. The results here demonstrate that EST,SSRs can be successfully used for genetic relationship analysis, extending the knowledge of genetic diversity of sugarcane to a functional level. [source] Genetic, Morphological, and Ecological Diversity of Spatially Separated Clones of Meseres corlissi Petz & Foissner, 1992 (Ciliophora, Spirotrichea)THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 4 2008THOMAS WEISSE ABSTRACT. We investigated the intraspecific variation of the spirotrich freshwater ciliate Meseres corlissi at the level of genes (SSrDNA, ITS), morphology (14 characters), and ecophysiology (response to temperature and pH). Five of the eight clonal M. corlissi cultures isolated from five localities on four continents were studied at all levels. The null hypothesis was that geographic distance plays no role: M. corlissi lacks biogeography. The intraspecific variation was low at the genetic level (0%,4%), moderate at the morphological level (5%,15%), and high at the ecophysiological level (10%,100%). One clone, isolated from subtropical China, differed significantly at all levels from all other clones, suggesting limited dispersal and local adaptation among M. corlissi. However, other clones from distant areas, such as Australia and Austria, were genetically identical and differed only slightly in morphology and temperature response. We speculate that our findings may be typical for rare species; the chances may be equally high for both global dispersal of most and local adaptation of some populations in areas where dispersal has been permanently or temporarily reduced. [source] Cybrids and tetrad sterility for developing true potato seed hybridsANNALS OF APPLIED BIOLOGY, Issue 2 2003ALI M GOLMIRZAIE Summary Potato cybrids result from the fusion between cytoplasm and nuclear gene donors. Such genetic materials are an alternative means to broaden the breeding pool by non-sexual gene transfer. Tetrad pollen sterility provides also another source of male sterility with some potential for true potato seed breeding. The objective of this research was to investigate cybrid-derived offspring for both agronomic and reproductive characteristics in two contrasting Peruvian locations, and to examine new exotic germplasm for tetrad sterility, with the aim of broadening the breeding pool available at the Centro Internacional de la Papa (CIP). The cybrids were derived from fusions between Y-245.7, a clone with tetrad sterility, and Atzimba. These cybrids were crossed with selected male parents from the CIP breeding population, and their hybrid offspring were tested in La Molina (coastal desert) and Huancayo (cool highlands). In addition, other clones with tetrad sterility were also crossed with selected testers to determine their breeding value. There were significant differences for tuber yield, style length, and berry number among the hybrid offspring, and the genotype by environment interaction was significant for tuber yield and berry number. The top 25% highest yielding cybrid-derived offspring across both locations showed the same tuber yield although they were significantly different for some of the reproductive characteristics. With the exception of one cybrid, the others did not exhibit segregation for tetrad sterility in their hybrid offspring, which were male fertile. However, the offspring derived from crosses between other sources of tetrad sterility and the same testers all showed tetrad sterility, and some of them had outstanding tuber yield at La Molina. The lack of segregation for tetrad sterility in these new crosses suggests that the non-cybrid, male sterile, female parents are triplex or quadriplex for the Tr nuclear locus, which interacts with a sensitive cytoplasm (e.g. Trs from S. verrucosum or S. stoloniferum) to produce tetrad sterility in potato. [source] Gene expression in distal intestine of Atlantic salmon (Salmo salar L.) fed genetically modified soybean mealAQUACULTURE NUTRITION, Issue 3 2008M.K. FRØYSTAD Abstract Limited availability of fishmeal leads to exploration of alternative protein sources like soybean meal (SBM). During the last decade, genetically modified (GM) plants have been introduced to the production of soybean crops. In the current experiment RNA was isolated from the distal intestinal section of Atlantic salmon fed either GM SBM or its near-isogenic parental line (non-GM), both at 30% inclusion. From a suppression subtractive hybridization cDNA library, 95 clones were sequenced. Clones with similarity to both known Atlantic salmon genes and novel Atlantic salmon sequences were identified. Real-time polymerase chain reaction was used to study differential expression of seven clones between the dietary groups. The clones were selected based on their relevance to intestinal immune responses and nutrient metabolism. Expression of a serum lectin-like clone was down-regulated in the GM group compared with the non-GM group. No differential expression was observed for six other clones with similarity to actin-related protein 2/3 complex-subunit 3, cysteine-rich intestinal protein, fatty acid binding protein/gastrotropin, ferritin heavy subunit, anterior gradient protein and peptide transporter. In conclusion, only minor differences in distal intestine transcriptional gene expression were observed between fish fed the diets with the non-GM and GM varieties. [source] | ||||||||||