Evaluation of combinatorial <Emphasis Type="Italic">cis</Emphasis>-regulatory elements for stable gene expression in chicken cells

Background  

Recent successes in biotechnological application of birds are based on their unique physiological traits such as unlimited manipulability onto developing embryos and simple protein constituents of the eggs. However it is not likely that target protein is produced as kinetically expected because various factors affect target gene expression. Although there have been various attempts to minimize the silencing of transgenes, a generalized study that uses multiple cis-acting elements in chicken has not been made. The aim of the present study was to analyze whether various cis-acting elements can help to sustain transgene expression in chicken fibroblasts.     

Production of Indole-3-Acetic Acid in the Plant-Beneficial Strain Pseudomonas chlororaphis O6 Is Negatively Regulated by the Global Sensor Kinase GacS

Certain plant growth–promoting bacteria, such as Pseudomonas fluorescens 89B61 and Bacillus pumilus SE34, secreted high levels of indole-3-acetic acid (IAA) in tryptophan-amended medium in stationary phase as determined by chromogenic analysis and high-performance liquid chromatography. Two other growth-promoting strains, P. chlororaphis O6 and Serratia marcescens 90-166, did not produce these high levels of IAA. However, when the gacS mutant of P. chlororaphis O6 was grown in tryptophan-supplemented medium, IAA was detected in culture filtrates. IAA production by the gacS mutant in P. chlororaphis O6 was repressed in the tryptophan medium by complementation with the wild-type gacS gene. Thus, the global regulatory Gac system in P. chlororaphis O6 acts as a negative regulator of IAA production from trypophan.     

Dose-dependent UV stabilization of p53 in cultured human cells undergoing apoptosis is mediated by poly(ADP-ribosyl)ation

The effect of poly(ADP-ribosyl)ation on the stability of p53 in SK-HEP1 cells treated with UV light was examined. Intracellular levels of p53 increased in cells treated with a low dose of UV light (20 J/m2), whereas they increased but then declined after a higher dose of UV (100 J/m2). Intracellular levels of p53 in the UV treated SK-HEP1 cells were dependent on the UV dose. Use of proteasome inhibitors revealed that p53 is degraded by proteasomal proteolysis after high doses of UV light. We present evidence that, at low doses, poly(ADP-ribose)polymerase (PARP) poly(ADP-ribosyl)ates p53 and protects it from proteasomal degradation before caspase-3 is activated, whereas at high doses the cells undergo UV induced apoptosis and PARP is cleaved by caspase-3 before it can protect p53 from degradation. Destabilization of p53 by cleavage of PARP may be important in cell fate decision favoring apoptosis.     

Synthesis and antibacterial activities of novel oxazolidinones having spiro[2,4]heptane moieties

The synthesis of a new series of oxazolidinones having spiro[2,4]heptane moieties is described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bacteria were tested and the effect of substituents on the oxazolidinone ring was investigated. A particular compound Ih having fluoro group showed the most potent antibacterial activity.     

Novel method for identifying individual cetaceans using facial features and symmetry: A test case using dolphins

Individual identification plays a major role in our understanding of the biology, ecology and behavior in cetaceans. Being able to tell individuals apart can provide invaluable insight into basic biological and scientific questions, but is also highly relevant to science‐based conservation. Given the importance of individual identification, it appears vital to improve existing identification methods and find new ones. Here, we present a novel identification method of using facial information, with common bottlenose dolphins (Tursiops truncatus) as a case study. In dolphins, dorsal fins are typically used for identification, but not all individuals or species are sufficiently marked. We show that facial features in bottlenose dolphins are long‐term and consistent across the left and right sides, and may enable calves (which tend to have unmarked fins) to be re‐identified after weaning, thus increasing cross‐generational knowledge. This novel method can complement dorsal fin identification by helping document mark changes over time and reduce false negative or positive errors. It also shows that current identification methods can still be improved. With increasing prevalence of digital photography and computer‐aided matching, it may become more viable to use ‘unconventional’ means of identification. We encourage other researchers to explore their photographic records for similar discoveries.     

Structural and functional comparative mapping between the Brassica A genomes in allotetraploid Brassica napus and diploid Brassica rapa

Brassica napus (AACC genome) is an important oilseed crop that was formed by the fusion of the diploids B. rapa (AA) and B. oleracea (CC). The complete genomic sequence of the Brassica A genome will be available soon from the B. rapa genome sequencing project, but it is not clear how informative the A genome sequence in B. rapa (A(r)) will be for predicting the structure and function of the A subgenome in the allotetraploid Brassica species B. napus (A(n)). In this paper, we report the results of structural and functional comparative mapping between the A subgenomes of B. napus and B. rapa based on genetic maps that were anchored with bacterial artificial chromosomes (BACs)-sequence of B. rapa. We identified segmental conservation that represented by syntenic blocks in over one third of the A genome; meanwhile, comparative mapping of quantitative trait loci for seed quality traits identified a dozen homologous regions with conserved function in the A genome of the two species. However, several genomic rearrangement events, such as inversions, intra- and inter-chromosomal translocations, were also observed, covering totally at least 5% of the A genome, between allotetraploid B. napus and diploid B. rapa. Based on these results, the A genomes of B. rapa and B. napus are mostly functionally conserved, but caution will be necessary in applying the full sequence data from B. rapa to the B. napus as a result of genomic rearrangements in the A genome between the two species.     

Production of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by Ralstonia eutropha from soybean oil

High-yield production of polyhydroxyalkanoates (PHAs) by Ralstonia eutropha KCTC 2662 was investigated using soybean oil and γ-butyrolactone as carbon sources. In flask culture, it was shown that R. eutropha KCTC 2662 accumulated PHAs during the growth phase. The optimum carbon to nitrogen ratio (C/N ratio) giving the highest cell and PHA yield was 20 g-soybean oil/g-(NH(4))(2)SO(4). The 4-hydroxybutyrate (4HB) fraction in the copolymer was not strongly affected by the C/N ratio. In a 2.5-L fermentor, a homopolymer of poly(3-hydroxybutyrate) [P(3HB)] was produced from soybean oil as the sole carbon source by batch and fed-batch cultures of R. eutropha with dry cell weights of 15-32 g/L, PHA contents of 78-83 wt% and yields of 0.80-0.82 g-PHA/g-soybean oil used. By co-feeding soybean oil and γ-butyrolactone as carbon sources, a copolymer of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] could be produced with dry cell weights of 10-21 g/L, yields of 0.45-0.56 g-PHA/g-soybean oil used (0.39-0.50g-PHA/g-carbon sources used) and 4HB fractions of 6-10 mol%. Higher supplementation of γ-butyrolactone increased the 4HB fraction in the copolymer, but decreased cell and PHA yield.     

Discrimination and Detection of Erwinia amylovora and Erwinia pyrifoliae with a Single Primer Set

Erwinia amylovora and Erwinia pyrifoliae cause fire blight and black-shoot blight, respectively, in apples and pears. E. pyrifoliae is less pathogenic and has a narrower host range than that of E. amylovora. Fire blight and black-shoot blight exhibit similar symptoms, making it difficult to distinguish one bacterial disease from the other. Molecular tools that differentiate fire blight from black-shoot blight could guide in the implementation of appropriate management strategies to control both diseases. In this study, a primer set was developed to detect and distinguish E. amylovora from E. pyrifoliae by conventional polymerase chain reaction (PCR). The primers produced amplicons of different sizes that were specific to each bacterial species. PCR products from E. amylovora and E. pyrifoliae cells at concentrations of 10⁴ cfu/ml and 10⁷ cfu/ml, respectively, were amplified, which demonstrated sufficient primer detection sensitivity. This primer set provides a simple molecular tool to distinguish between two types of bacterial diseases with similar symptoms.