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Determined Sequence (determine + sequence)
Selected AbstractsDissociating hippocampal subregions: A double dissociation between dentate gyrus and CA1HIPPOCAMPUS, Issue 6 2001Paul E. Gilbert Abstract This study presents a double dissociation between the dentate gyrus (DG) and CA1. Rats with either DG or CA1 lesions were tested on tasks requiring either spatial or spatial temporal order pattern separation. To assess spatial pattern separation, rats were trained to displace an object which covered a baited food-well. The rats were then allowed to choose between two identical objects: one covered the same well as the sample phase object (correct choice), and a second object covered a different unbaited well (incorrect choice). Spatial separations of 15,105 cm were used to separate the correct object from the incorrect object. To assess spatial temporal order pattern separation, rats were allowed to visit each arm of a radial eight-arm maze once in a randomly determined sequence. The rats were then presented with two arms and were required to choose the arm which occurred earliest in the sequence. The choice arms varied according to temporal separation (0, 2, 4, or 6) or the number of arms that occurred between the two choice arms in the sample phase sequence. On each task, once a preoperative criterion was reached, each rat was given either a DG, CA1, or control lesion and then retested. The results demonstrated that DG lesions resulted in a deficit on the spatial task but not the temporal task. In contrast, CA1 lesions resulted in a deficit on the temporal task but not the spatial task. Results suggest that the DG supports spatial pattern separation, whereas CA1 supports temporal pattern separation. Hippocampus 2001;11:626,636. © 2001 Wiley-Liss, Inc. [source] Bacterial diversity of the digestive gland of Sydney rock oysters, Saccostrea glomerata infected with the paramyxean parasite, Marteilia sydneyiJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2010T.J. Green Abstract Aims:, To determine whether the infestation by the protozoan paramyxean parasite, Marteilia sydneyi, changes the bacterial community of the digestive gland of Sydney rock oysters, Saccostrea glomerata. Methods and Results:, Six 16S rDNA clone libraries were established from three M. sydneyi -infected and three un-infected oysters. Restriction enzyme analysis followed by sequencing representative clones revealed a total of 23 different operational taxonomic units (OTUs) in un-infected oysters, comprising the major phyla: Firmicutes, Proteobacteria, Cyanobacteria and Spirocheates, where the clone distribution was 44, 36, 7 and 5%, respectively. Close to half of the OTUs are not closely related to any other hitherto determined sequence. In contrast, S. glomerata infected by M. sydneyi had only one OTU present in the digestive gland. Phylogenetic analysis of the 16S rDNA sequence reveals that this dominant OTU, belonging to the ,-Proteobacteria, is closely related to a Rickettsiales -like prokaryote (RLP). Conclusions:, The microbiota of the digestive gland of Sydney rock oysters is changed by infection by M. sydneyi, becoming dominated by a RLP, and generally less diverse. The bacterial community of un-infected S. glomerata differs from previous studies in that we identified the dominant taxa as Firmicutes and ,-Proteobacteria, rather than heterotrophic ,-Proteobacteria. Significance and Impact of the Study:, This is the first culture-independent study of the microbiota of the digestive glands of edible oysters to the species level. The commercial viability of the Sydney rock oyster industry in Australia is currently threatened by Queensland Unknown disease and the changes in the bacterial community of S. glomerata corresponding with infection by M. sydneyi sheds further light on the link between parasite infection and mortality in this economically damaging disease. [source] Identification and detection of Pseudomonas plecoglossicida isolates with PCR primers targeting the gyrB regionJOURNAL OF FISH DISEASES, Issue 7 2007S Izumi Abstract Pseudomonas plecoglossicida is the agent of bacterial haemorrhagic ascites (BHA) in freshwater fish farming in Japan. To develop a rapid identification and detection method for P. plecoglossicida, a PCR amplification technique targeting the chromosomal DNA region coding the B subunit of the DNA gyrase (gyrB) was used. The nucleotide sequences of gyrB were determined in nine isolates of P. plecoglossicida and two other Pseudomonas species. On the basis of these determined sequences and the gyrB sequences of other Pseudomonas species or fish pathogenic bacteria deposited in international nucleotide sequence databases (GenBank/EMBL/DDBJ), PCR primers PL-G1F, PL-G1R, PL-G2F and PL-G2R were designed for specific amplification of the partial gyrB of P. plecoglossicida. The specificity of these primers in amplifying the gyrB of P. plecoglossicida was verified using selected strains of related bacterial species. The nested PCR technique was used to detect P. plecoglossicida from kidney and intestine of ayu. Primer pair PL-G1F and PL-G1R was used for the external PCR, and primer pair PL-G2F and PL-G2R for the internal PCR. Of 10 ayu juveniles, expected size PCR products were observed from intestine and kidney samples in one and two specimens, respectively. The PCR technique with primers based on the gyrB sequence is thus useful for the diagnosis of BHA. [source] Comparison of the distribution patterns of BK polyomavirus lineages among China, Korea and Japan: Implications for human migrations in northeast AsiaMICROBIOLOGY AND IMMUNOLOGY, Issue 5 2009Shan Zhong ABSTRACT BKV is widespread among humans, infecting children asymptomatically and then persisting in renal tissue. Based on the serological or phylogenetic method, BKV isolates worldwide are classified into four subtypes (I,IV), with subtypes I and IV further divided into several genetically-distinct subgroups. Since, similarly to JCV, a close relationship exists between BKV lineages and human populations, BKV should be useful as a marker to trace human migrations. To elucidate ancient human migrations in northeast Asia, urine samples were collected from immunocompetent elderly patients in Shanghai, China; Anyang, South Korea; and various locations in Japan. Partial and complete BKV genomes from these samples were amplified and sequenced using PCR, and the determined sequences were classified into subtypes and subgroups by phylogenetic and SNP analyses. In addition, based on an SNP analysis, the major subtype I subgroup (I/c) was classified into two subdivisions, I/c/Ch and I/c/KJ. The distribution patterns of BKV subgroups and subdivisions among the three regions were compared. Some aspects of the subgroup and subdivision distribution were more similar between Korea and Japan, but others were more similar between China and Korea or between China and Japan. Based on these findings, we inferred various northeast Asian migrations. Most of the JCV-based inferences of northeastern Asian migrations were consistent with those based on BKV, but the previously suggested migration route from the Asian continent to the Japanese archipelago seemed to need revision. [source] | ||||||||||