Molecular and morphological characterization of somatic hybrids between <Emphasis Type="Italic">Solanum tuberosum</Emphasis> L. and <Emphasis Type="Italic">S. etuberosum</Emphasis> Lindl.

Interspecific potato somatic hybrids between Solanum tuberosum L. (di)haploid C-13 and 1 endosperm balance number non-tuberous wild species S. etuberosum Lindl. were produced by protoplasts electrofusion. The objective was to transfer virus resistance from this wild species into the cultivated potatoes. Post-fusion products were cultured in VKM medium followed by regeneration of calli in MS₁₃ K medium at 20°C under a 16-h photoperiod, and regenerants were multiplied on MS medium. Twenty-one somatic hybrids were confirmed by RAPD, SSR and cytoplasm (chloroplast/mitochondria) type analysis possessing species-specific diagnostic bands of corresponding parents. Tetraploid nature of these somatic hybrids was determined through flow cytometry analysis. Somatic hybrids showed intermediate phenotypes (plant, leaves and floral morphology) to their parents in glass-house grown plants. All the somatic hybrids were male-fertile. ELISA assay of somatic hybrids after artificial inoculation of Potato virus Y (PVY) infection reveals high PVY resistance.     

Enumerative and binomial sequential sampling plans for the multicolored Asian lady beetle (Coleoptera: Coccinellidae) in wine grapes

To develop a practical integrated pest management (IPM) system for the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), in wine grapes, we assessed the spatial distribution of H. axyridis and developed eight sampling plans to estimate adult density or infestation level in grape clusters. We used 49 data sets collected from commercial vineyards in 2004 and 2005, in Minnesota and Wisconsin. Enumerative plans were developed using two precision levels (0.10 and 0.25); the six binomial plans reflected six unique action thresholds (3, 7, 12, 18, 22, and 31% of cluster samples infested with at least one H. axyridis). The spatial distribution of H. axyridis in wine grapes was aggregated, independent of cultivar and year, but it was more randomly distributed as mean density declined. The average sample number (ASN) for each sampling plan was determined using resampling software. For research purposes, an enumerative plan with a precision level of 0.10 (SE/X) resulted in a mean ASN of 546 clusters. For IPM applications, the enumerative plan with a precision level of 0.25 resulted in a mean ASN of 180 clusters. In contrast, the binomial plans resulted in much lower ASNs and provided high probabilities of arriving at correct "treat or no-treat" decisions, making these plans more efficient for IPM applications. For a tally threshold of one adult per cluster, the operating characteristic curves for the six action thresholds provided binomial sequential sampling plans with mean ASNs of only 19-26 clusters, and probabilities of making correct decisions between 83 and 96%. The benefits of the binomial sampling plans are discussed within the context of improving IPM programs for wine grapes.     

DNA sequencing: bench to bedside and beyond

Fifteen years elapsed between the discovery of the double helix (1953) and the first DNA sequencing (1968). Modern DNA sequencing began in 1977, with development of the chemical method of Maxam and Gilbert and the dideoxy method of Sanger, Nicklen and Coulson, and with the first complete DNA sequence (phage ϕX174), which demonstrated that sequence could give profound insights into genetic organization. Incremental improvements allowed sequencing of molecules >200 kb (human cytomegalovirus) leading to an avalanche of data that demanded computational analysis and spawned the field of bioinformatics. The US Human Genome Project spurred sequencing activity. By 1992 the first ‘sequencing factory’ was established, and others soon followed. The first complete cellular genome sequences, from bacteria, appeared in 1995 and other eubacterial, archaebacterial and eukaryotic genomes were soon sequenced. Competition between the public Human Genome Project and Celera Genomics produced working drafts of the human genome sequence, published in 2001, but refinement and analysis of the human genome sequence will continue for the foreseeable future. New ‘massively parallel’ sequencing methods are greatly increasing sequencing capacity, but further innovations are needed to achieve the ‘thousand dollar genome’ that many feel is prerequisite to personalized genomic medicine. These advances will also allow new approaches to a variety of problems in biology, evolution and the environment.     

Conserved cysteine residues in the mammalian lamin A tail are essential for cellular responses to ROS generation

Pre-lamin A and progerin have been implicated in normal aging, and the pathogenesis of age-related degenerative diseases is termed 'laminopathies'. Here, we show that mature lamin A has an essential role in cellular fitness and that oxidative damage to lamin A is involved in cellular senescence. Primary human dermal fibroblasts (HDFs) aged replicatively or by pro-oxidants acquire a range of dysmorphic nuclear shapes. We observed that conserved cysteine residues in the lamin A tail domain become hyperoxidized in senescent fibroblasts, which inhibits the formation of lamin A inter- and intramolecular disulfide bonds. Both in the absence of lamin A and in the presence of a lamin A cysteine-to-alanine mutant, which eliminates these cysteine residues (522, 588, and 591), mild oxidative stress induced nuclear disorganization and led to premature senescence as a result of decreased tolerance to ROS stimulators. Human dermal fibroblasts lacking lamin A or expressing the lamin A cysteine-to-alanine mutant displayed a gene expression profile of ROS-responsive genes characteristic of chronic ROS stimulation. Our findings suggest that the conserved C-terminal cysteine residues are essential for lamin A function and that loss or oxidative damage to these cysteine residues promotes cellular senescence.     

Discovery of an ebolavirus-like filovirus in europe

Filoviruses, amongst the most lethal of primate pathogens, have only been reported as natural infections in sub-Saharan Africa and the Philippines. Infections of bats with the ebolaviruses and marburgviruses do not appear to be associated with disease. Here we report identification in dead insectivorous bats of a genetically distinct filovirus, provisionally named Lloviu virus, after the site of detection, Cueva del Lloviu, in Spain.     

The chemical ecology of <Emphasis Type="Italic">Harmonia axyridis</Emphasis>

We review the chemical ecology of the ladybird beetle Harmonia axyridis from the perspective of its invasiveness and the deleterious effects it exerts in the regions it has colonised. We outline the nature and quantification of its chemical defence, and discuss the protection this provides against natural enemies, particularly intraguild predators. We consider the role of infochemicals in location of prey, intraspecific communication and intraguild interactions. We also discuss the role of prey allelochemicals in relation to H. axyridis extreme dietary generalism. Harmonia axyridis poses a number of practical problems for human health and well-being, including “ladybug taint” wine contamination and problems resulting from large aggregations overwintering in buildings. We consider chemical insights into these issues and, in particular, how attractants and repellents might help manage H. axyridis populations through a push–pull strategy. We conclude by discussing future perspectives for research.     

Lamin A/C-dependent localization of Nesprin-2, a giant scaffolder at the nuclear envelope

The vertebrate proteins Nesprin-1 and Nesprin-2 (also referred to as Enaptin and NUANCE) together with ANC-1 of Caenorhabditis elegans and MSP-300 of Drosophila melanogaster belong to a novel family of alpha-actinin type actin-binding proteins residing at the nuclear membrane. Using biochemical techniques, we demonstrate that Nesprin-2 binds directly to emerin and the C-terminal common region of lamin A/C. Selective disruption of the lamin A/C network in COS7 cells, using a dominant negative lamin B mutant, resulted in the redistribution of Nesprin-2. Furthermore, using lamin A/C knockout fibroblasts we show that lamin A/C is necessary for the nuclear envelope localization of Nesprin-2. In normal skin where lamin A/C is differentially expressed, strong Nesprin-2 expression was found in all epidermal layers, including the basal layer where only lamin C is present. This indicates that lamin C is sufficient for proper Nesprin-2 localization at the nuclear envelope. Expression of dominant negative Nesprin-2 constructs and knockdown studies in COS7 cells revealed that the presence of Nesprin-2 at the nuclear envelope is necessary for the proper localization of emerin. Our data imply a scaffolding function of Nesprin-2 at the nuclear membrane and suggest a potential involvement of this multi-isomeric protein in human disease.