Genetic Diversity of Vibrio cholerae in Chesapeake Bay Determined by Amplified Fragment Length Polymorphism Fingerprinting

Vibrio cholerae is indigenous to the aquatic environment, and serotype non-O1 strains are readily isolated from coastal waters. However, in comparison with intensive studies of the O1 group, relatively little effort has been made to analyze the population structure and molecular evolution of non-O1 V. cholerae. In this study, high-resolution genomic DNA fingerprinting, amplified fragment length polymorphism (AFLP), was used to characterize the temporal and spatial genetic diversity of 67 V. cholerae strains isolated from Chesapeake Bay during April through July 1998, at four different sampling sites. Isolation of V. cholerae during the winter months (January through March) was unsuccessful, as observed in earlier studies (J. H. L. Kaper, R. R. Colwell, and S. W. Joseph, Appl. Environ. Microbiol. 37:91–103, 1979). AFLP fingerprints subjected to similarity analysis yielded a grouping of isolates into three large clusters, reflecting time of the year when the strains were isolated. April and May isolates were closely related, while July isolates were genetically diverse and did not cluster with the isolates obtained earlier in the year. The results suggest that the population structure of V. cholerae undergoes a shift in genotype that is linked to changes in environmental conditions. From January to July, the water temperature increased from 3°C to 27.5°C, bacterial direct counts increased nearly an order of magnitude, and the chlorophyll a concentration tripled (or even quadrupled at some sites). No correlation was observed between genetic similarity among isolates and geographical source of isolation, since isolates found at a single sampling site were genetically diverse and genetically identical isolates were found at several of the sampling sites. Thus, V. cholerae populations may be transported by surface currents throughout the entire Bay, or, more likely, similar environmental conditions may be selected for a specific genotype. The dynamic nature of the population structure of this bacterial species in Chesapeake Bay provides new insight into the ecology and molecular evolution of V. cholerae in the natural environment.     

The Neoliberal World Order and Patriarchal Power: A Discursive Study of Korean Cinema and International Co-production

This research is an attempt to examine the ideological aspects of Korean cinema in the context of politico-economic changes. Korean cinema is in the process of economic restructuring, driven by neoliberal forces on a global scale. These economic forces also influence film texts on a concrete level, creating hybrid characters and narratives in blockbusters and co-produced films. These new genre films have tended to reinforce patriarchal ideology, making it increasingly pronounced, as Korean films become more technologically advanced and the production system globalized. To illustrate these effects, this article offers a textual analysis of Never Forever [Kim Jina 2007], which was the first U.S.–Korean co-production.     

A modular master regulator landscape controls cancer transcriptional identity

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Potentiation of sympathetic neurotransmission in bovine isolated irides by isoprostanes

Isoprostanes (IsoP) are formed by free radical catalyzed peroxidation of arachidonic acid independent of the cyclooxygenase enzyme. In the present study, we examined the effect of IsoP on norepinephrine (NE) release from the bovine isolated iris. Furthermore, we studied the role of IsoP's in hydrogen peroxide (H₂O₂)-induced enhancement of NE release from this tissue. Isolated bovine irides were prepared for studies of [³H]NE release using the superfusion method. Release of [³H]NE was induced via electrical field stimulation. Both 8-iso-prostaglandin E₂ (E₂-IsoP) and 8-iso-prostaglandin F_2α (F₂-IsoP) produced a concentration-related enhancement of field-stimulated [³H]NE release from isolated bovine irides, an effect that was mimicked by the thromboxane (Tx) receptor agonist, U46619 and by H₂O₂. The Tx-receptor antagonist, SQ 29548 inhibited responses to E₂-IsoP (10μM) with an IC₅₀ of 370±50 nM. SQ 29548 (10μM) also blocked the enhancement of electrically-evoked [³H]NE release induced by U46619 (10μM) but not that caused by H₂O₂ (300μM). The Tx synthetase inhibitor, carboxyheptylimidazole (10μM) prevented the stimulatory effect of E₂-IsoP on evoked [³H]NE release without affecting responses induced by H₂O₂. We conclude that IsoP's can enhance sympathetic neurotransmission in the bovine isolated iris, an effect that can be blocked by a Tx-receptor antagonist. Furthermore, endogenously produced Tx's mediate the stimulatory effect of IsoP's on NE release. However, endogenously generated IsoP's or Tx's are not involved in H₂O₂-induced potentiation of sympathetic neurotransmission.     

A novel lincRNA identified in buffalo oocytes with protein binding characteristics could hold the key for oocyte competence

Molecular Biology Reports - Studying the maternal oocyte-specific genes, in farm animals is a significant step towards delineating the underlying mechanisms that regulate oocyte quality, early...     

Molecular Characterization and Recombination Analysis of the Complete Genome of Apple Chlorotic Leaf Spot Virus

The complete nucleotide sequence of an Indian isolate of Apple chlorotic leaf spot virus (ACLSV) was determined and found to be 7,525 nt in length. The genome organization was similar to known isolates of ACLSV, encoding three ORFs. Comparisons indicated high sequence variability among known isolates with overall nucleotide sequence identities of 80 to 84%. A striking variable region was identified among the replicase protein upstream of the RNA‐dependent RNA polymerase (aa 1510–1590), which showed a 41–43% match with the corresponding region in other isolates. Phylogenetic analysis at the nucleotide level clustered the isolates into three groups, without any relation to geographical origin. Recombination analysis showed that the isolate is a recombinant with recombination sites spread throughout the genome, especially in the polymerase gene region (nt 4700–5400). Most recombination sites were bordered by an upstream region (5′) of GC‐rich and downstream region (3′) of AU‐rich sequences of similar length. Correlation of recombination site with host type is discussed, and it was found that there were more interlineage recombinations in the apple host compared with intralineage recombinations.