Glycoprotein I of varicella-zoster virus is required for viral replication in skin and T cells

Varicella-zoster virus (VZV) glycoprotein I (gI) is dispensable in cell culture; the SCIDhu model of VZV pathogenesis was used to determine whether gI is necessary in vivo. The parental and repaired viruses grew in human skin and thymus/liver implants, but the gI deletion mutant was not infectious. Thus, gI is essential for VZV infectivity in skin and T cells.     

Characterization of lactic acid bacteria in the larval midgut of the keratinophagous lepidopteran, Hofmannophila pseudospretella

In two of eight Hofmannophila pseudospretella specimens studied by microscopy, the larval midgut contained an unidentified micro-organism. Although not seen microscopically in midgut sections, bacteria were isolated from dissected midgut. Microscopy, carbohydrate utilization and ribosomal sequence data all separated the isolates into the same three classes. These were identified as Lactococcus lactis, Carnobacterium piscicola and, tentatively, Bacillus subtilis, the first two being facultative anaerobes and the latter, an aerobe. The bacteria were therefore not specifically adapted to the reducing conditions of the midgut.     

GRIM-19, a cell death regulatory gene product, is a subunit of bovine mitochondrial NADH:ubiquinone oxidoreductase (complex I)

The sequences of 42 subunits of NADH:ubiquinone oxidoreductase (complex I) from bovine heart mitochondria have been described previously. Seven are encoded by mitochondrial DNA, whereas the remaining 35 are nuclear gene products imported into the organelle from the cytoplasm. An additional protein, which does not correspond to any previously known subunit of the complex I assembly, has now been detected. Denaturing gels of subcomplex Ilambda, the hydrophilic arm of complex I, clearly show a hitherto unidentified band, which was digested with trypsin and subjected to mass-spectrometric analysis to provide several peptide sequences, used in cDNA cloning and sequencing. Measurement of the intact protein mass indicated that the N terminus is acetylated. The new complex I subunit (B16.6) is the bovine homolog of GRIM-19, the product of a cell death regulatory gene induced by interferon-beta and retinoic acid, thus providing a new link between the mitochondrion and its electron-transport chain and apoptotic cell death.     

A molecular approach to the identification and individualization of human and animal cells in culture: Isozyme and allozyme genetic signatures

Summary The electrophoretic resolution of a group of geneticallymonomorphic gene-enzyme systems that are developmentally and biologically ubiquitous has been used to provide a species-specific and type-specific biochemical characterization of various cultured cells. The relative mobilities of gene-enzyme systems representing nine distinct gene products from cell cultures of 25 species fromDrosophils to man are presented. These isoenzymes effectively discriminate interspecies cell-to-cell contamination and almost invariably serve to identify the contaminating species. The resolution of eightpolymorphic gene-enzyme systems in human cell cultures provides a virtually unique allozyme genetic signature as a monitor of intraspecies cellular contamination. The genetic signatures of 47 commonly used human cells are presented. Included in the test were seven putative HeLa (human cervical carcinoma) contaminants each of which expressed a signature identical with that of HeLa. The probability that an unrelated human cell line will have a signature identical to a typed cell is computed for each line from the genotypic frequencies at each locus in a population of cultured human cells. The gene frequencies of this cell population are comparable to the same frequencies in natural human populations. The most common human signature has a frequency (and therefore a probability) of 0.02. The majority of the 17,010 possible signatures are far less probable. A calculation of the theoretical incidence of chance matching of signatures within test groups of two or more individuals is presented. The probability of a chance match between any two randomly selected individuals is 0.004 and among five randomly selected individuals is 0.034. The allozyme genetic signature represents a definitive monitor of cell identity and is presented as a standard of cell and tissue identification for a variety of biological studies. This work was supported in part by the Virus Cancer Program of the National Cancer Institute.     

Foraging by forest ants under experimental climatic warming: a test at two sites

Climatic warming is altering the behavior of individuals and the composition of communities. However, recent studies have shown that the impact of warming on ectotherms varies geographically: species at warmer sites where environmental temperatures are closer to their upper critical thermal limits are more likely to be negatively impacted by warming than are species inhabiting relatively cooler sites. We used a large‐scale experimental temperature manipulation to warm intact forest ant assemblages in the field and examine the impacts of chronic warming on foraging at a southern (North Carolina) and northern (Massachusetts) site in eastern North America. We examined the influence of temperature on the abundance and recruitment of foragers as well as the number of different species observed foraging. Finally, we examined the relationship between the mean temperature at which a species was found foraging and the critical thermal maximum temperature of that species, relating functional traits to behavior. We found that forager abundance and richness were related to the experimental increase in temperature at the southern site, but not the northern site. Additionally, individual species responded differently to temperature: some species foraged more under warmer conditions, whereas others foraged less. Importantly, these species‐specific responses were related to functional traits of species (at least at the Duke Forest site). Species with higher critical thermal maxima had greater forager densities at higher temperatures than did species with lower critical thermal maxima. Our results indicate that while climatic warming may alter patterns of foraging activity in predictable ways, these shifts vary among species and between sites. More southerly sites and species with lower critical thermal maxima are likely to be at greater risk to ongoing climatic warming.     

Comparative Analysis of DNA Nanoparticles and AAVs for Ocular Gene Delivery

Gene therapy is a critical tool for the treatment of monogenic retinal diseases. However, the limited vector capacity of the current benchmark delivery strategy, adeno-associated virus (AAV), makes development of larger capacity alternatives, such as compacted DNA nanoparticles (NPs), critical. Here we conduct a side-by-side comparison of self-complementary AAV and CK30PEG NPs using matched ITR plasmids. We report that although AAVs are more efficient per vector genome (vg) than NPs, NPs can drive gene expression on a comparable scale and longevity to AAV. We show that subretinally injected NPs do not leave the eye while some of the AAV-injected animals exhibited vector DNA and GFP expression in the visual pathways of the brain from PI-60 onward. As a result, these NPs have the potential to become a successful alternative for ocular gene therapy, especially for the multitude of genes too large for AAV vectors.     

Molecular Mechanisms of Disease-Causing Missense Mutations

Genetic variations resulting in a change of amino acid sequence can have a dramatic effect on stability, hydrogen bond network, conformational dynamics, activity and many other physiologically important properties of proteins. The substitutions of only one residue in a protein sequence, so-called missense mutations, can be related to many pathological conditions and may influence susceptibility to disease and drug treatment. The plausible effects of missense mutations range from affecting the macromolecular stability to perturbing macromolecular interactions and cellular localization. Here we review the individual cases and genome-wide studies that illustrate the association between missense mutations and diseases. In addition, we emphasize that the molecular mechanisms of effects of mutations should be revealed in order to understand the disease origin. Finally, we report the current state-of-the-art methodologies that predict the effects of mutations on protein stability, the hydrogen bond network, pH dependence, conformational dynamics and protein function.