A novel zinc bis(thiosemicarbazone) complex for live cell imaging

Fluorescent zinc complexes have recently attracted a lot of interest owing to their vast applications in cellular imaging. We report the synthesis as well as physical, chemical and biological studies of a novel zinc glyoxalbis(4-methyl-4-phenyl-3-thiosemicarbazone), [Zn(GTSC)]₃, complex. As compared with the well-studied zinc biacetylbis(4-methyl-3-thiosemicarbazone), Zn(ATSM), complex, which was used as a reference, [Zn(GTSC)]₃ had 2.5-fold higher fluorescence. When cellular fluorescence was measured using flow cytometry, we observed that [Zn(GTSC)]₃ had 3.4-fold to 12-fold higher fluorescence than Zn(ATSM) in various cell lines (n = 9) of different tissue origin. Confocal fluorescence microscopy results showed that [Zn(GTSC)]₃ appeared to have a nuclear localization within 30 min of addition to MCF7 cells. Moreover, [Zn(GTSC)]₃ showed minimal cytotoxicity compared with Zn(ATSM), suggesting that [Zn(GTSC)]₃ may be less deleterious to cells when used as an imaging agent. Our data suggest that the novel [Zn(GTSC)]₃ complex can potentially serve as a biocompatible fluorescent imaging agent for live cells.     

Biodiversity and conservation of insects and other invertebrates

The thematic issue of Biodiversity and Conservation devoted to the biodiversity and conservation of insects and other invertebrates is introduced. The issue comprises 23 original research papers covering diverse habitats from forests to grasslands, ponds and rivers to coasts, and the tropics to boreal regions. Amongst the organisms discussed are ants, bees, beetles, butterflies, crabs, microgastropods, millipedes, spiders, and weevils. Some of the difficulties of conserving the most species-rich groups of eukaryotes, in the face of ignorance as to their identities and positions in ecological processes, are noted and the precautionary principle is seen as a pragmatic and responsible approach.     

A macronutrient optimization platform for micropropagation and acclimatization: using turmeric (<Emphasis Type=Italic>Curcuma longa</Emphasis> L.) as a model plant

Tissue culture medium is often overlooked as a factor in plant biotechnology. Most work uses Murashige and Skoog (MS; Physiol Plant in 15:473–497, 1962) inorganic medium formulation, which is not likely optimal for many of the plant systems where it is used. This current study of macronutrient factors simultaneously altered media volume and amount of tissue (plants per vessel), sucrose, nitrogen (as NO₃⁻ and NH₄⁺ ions), and K⁺ in a d-optimal design space with only 55 experimental units (including five true replicates). Meso- and micro-nutrient concentrations were lowered (5% of MS) to determine which elements were most critical to plantlet quality. Plantlet quality was quantified by multiplication in the laboratory and survival and growth in the greenhouse. Plantlets grown at the lowest plant density, the lowest macronutrient concentration (20 mM), and equi-molar proportions of NH₄⁺/K⁺ resulted in the best multiplication ratio and 100% greenhouse survival. Multiplication ratio in vitro and survival in the greenhouse were well correlated with one another. Laboratory dry mass, media use, sucrose use, and the uptake of the macronutrients NO₃⁻, NH₄⁺, and K⁺ were not well correlated with plantlet quality. Plantlets with the greatest uptake of P, Ca, Mg, and Mn had the best multiplication in the laboratory and on subsequent transfer, acclimatized and grew fastest in the greenhouse. Phosphorus was shown to be most depleted in media. This work demonstrates a platform to simultaneously optimize several nutritive components of tissue culture media to produce plantlets that perform well in both laboratory and greenhouse environments. Plant quality was related with factors outside the macronutrient design, and this platform indicated where to expand the experimental space. Fixed, flat-screen presentations revealed less of the response surface than interactive profiles driven by the reader.     

Conversion of AFLP markers to high-throughput markers in a complex polyploid,sugarcane

The application of DNA markers linked to traits of commercial value in sugarcane may increase the efficiency of sugarcane breeding. The majority of markers generated for quantitative trait locus mapping in sugarcane have been single sequence repeats or AFLPs (amplified fragment length polymorphisms). Since AFLP markers are not adapted for large-scale implementation in plant breeding, our objective was to assess the feasibility of converting AFLP markers to fast, cheap and reliable PCR-based assays in a complex polyploid, sugarcane. Three AFLP markers were selected on the basis of an association to resistance to the fungal pathogen Ustilago scitaminea, the causal agent of smut in sugarcane. We developed an approach which enabled the identification of polymorphisms in these AFLP markers. Towards this goal, we employed GenomeWalking and 454 sequencing to isolate sequences adjacent to the linked AFLP markers and identify SNP (single nucleotide polymorphisms) haplotypes present in the homo(eo)logous chromosomes of sugarcane. One AFLP marker was converted to a cleavage amplified polymorphic sequence marker, another to a SCAR (sequence characteristered amplified region) marker and the final AFLP marker to a SNP PCR-based assay. However, validation of each of the markers in 240 genotypes resulted in 99, 90 and 60% correspondence with the original AFLP marker. These experiments indicate that even in a complex polyploid such as sugarcane, polymorphisms identified by AFLP can be converted to high-throughput marker systems, but due to the complexity this would only be carried out for high-value markers. In some cases, the polymorphisms identified are not transferable to more sequence-specific PCR applications.     

Taxon-specific multiplex-PCR for quick,easy, and accurate identification of encyrtid and aphelinid parasitoid species attacking soft scale insects in California citrus groves

Citricola scale, Coccus pseudomagnoliarum Kuwana (Hemiptera: Coccidae), is a serious pest of citrus in California’s San Joaquin Valley, but not in southern California where a complex of Metaphycus spp. Mercet (Hymenoptera: Encyrtidae) suppress it. This has created interest in using these (and other Metaphycus) species for biological control in the San Joaquin Valley. A critical step in assessing an organism’s potential for biological control is the ability to accurately identify it. For Metaphycus spp., this currently requires slide mounted adult specimens and expert taxonomic knowledge. We present a simple, quick and accurate method to identify any life stage of the ten major parasitoids of soft scales in California citrus, based on amplification of ribosomal DNA, using the polymerase chain reaction (PCR). Three multiplex-PCR protocols amplify products of taxon-specific sizes, allowing direct diagnosis of taxa accommodated by the PCR, and reducing identification time to a fraction of that of existing methods.     

Shrimp Molecular Responses to Viral Pathogens

From almost negligible amounts in 1970, the quantity of cultivated shrimp (∼3 million metric tons in 2007) has risen to approach that of the capture fishery and it constitutes a vital source of export income for many countries. Despite this success, viral diseases along the way have caused billions of dollars of losses for shrimp farmers. Desire to reduce the losses to white spot syndrome virus in particular, has stimulated much research since 2000 on the shrimp response to viral pathogens at the molecular level. The objective of the work is to develop novel, practical methods for improved disease control. This review covers the background and limitations of the current work, baseline studies and studies on humoral responses, on binding between shrimp and viral structural proteins and on intracellular responses. It also includes discussion of several important phenomena (i.e., the quasi immune response, viral co-infections, viral sequences in the shrimp genome and persistent viral infections) for which little or no molecular information is currently available, but is much needed.     

Aqueous solubility of a diatomic molecule as a function of its size &; electronegativity difference

The aqueous solubility of a diatomic molecule as a function of its size & electronegativity difference is investigated. The electronegativity of a diatomic molecule will be calculated using five different electronegativity scales, namely, Pauling [1], Allred-Rochow [2], Mulliken [3, 4], Parr-Yang [5], and Sanderson [6, 7]. It is hypothesized here that at a given pH, temperature, and pressure, the solubility of a diatomic molecule in water will be a function of its polar character; in particular, electronegativity difference and of its molecular size. Different forms of the solubility function were tested; it was found that the solubility model, given by Eq. 3, which is based on different electronegativity scales and the molecular volume, adequately describes the aqueous solubility of alkali halides. The aqueous solubility of alkali halides exhibits maximum at the condition of high electronegativity difference and large molecular volume. On the other hand, the minimum solubility region is observed at very low molecular volume and medium to slightly high values of electronegativity difference. The minimum solubility is also observed at low value of electronegativity difference and high molecular volume. Finally, the general trend of solubility of alkali halides, based on the proposed model (Eq. 3) could be explained in terms of the trade-off between electrostatic interactions (solid lattice side) and the entropic effects (water side).