Molecular biology of insect olfaction:recent progress and conceptual models

Insects have an enormous impact on global public health as disease vectors and as agricultural enablers as well as pests and olfaction is an important sensory input to their behavior. As such it is of great value to understand the interplay of the molecular components of the olfactory system which, in addition to fostering a better understanding of insect neurobiology, may ultimately aid in devising novel intervention strategies to reduce disease transmission or crop damage. Since the first discovery of odorant receptors in vertebrates over a decade ago, much of our view on how the insect olfactory system might work has been derived from observations made in vertebrates and other invertebrates, such as lobsters or nematodes. Together with the advantages of a wide range of genetic tools, the identification of the first insect odorant receptors in Drosophila melanogaster in 1999 paved the way for rapid progress in unraveling the question of how olfactory signal transduction and processing occurs in the fruitfly. This review intends to summarize much of this progress and to point out some areas where advances can be expected in the near future.     

Association of polymorphic markers I/D of gene ACE and A1166C of gene AT2R1 with ischemic chronic heart failure in the Russian and Tatar populations of Bashkortostan Republic

Polymerase chain reaction was used to study the association of polymorphic markers I/D of the angiotensin-converting enzyme gene (ACE) and A1166C of the angiotensin II type 1 receptor gene (AT2R1) with chronic heart failure (CHF) in Russian and Tatar patients that had had myocardial infarction. In Russian patients aged 50 years or younger that had had macrofocal myocardial infarction, the CC genotype of the A1166C polymorphic marker of gene AT2R1 was associated with an increased risk of CHF (OR = 11.36). Genotype DD and allele D of the I/D polymorphic marker of gene ACE were associated with a more severe CHF (functional class III–IV) in Russian patients (OR = 3.50 and 2.06). In Tatar patients, polymorphic markers I/D of gene ACE and A1166C of gene AT2R1 were not associated with CHF.     

Association of polymorphic markers I/D of gene ACE and A1166C of gene AT2R1 with ischemic chronic heart failure in the Russian and Tatar populations of Bashkortostan Republic

Polymerase chain reaction was used to study the association of polymorphic markers I/D of the angiotensin-converting enzyme gene (ACE) and A1166C of the angiotensin II type 1 receptor gene (AT2R1) with chronic heart failure (CHF) in Russian and Tatar patients that had had myocardial infarction. In Russian patients aged 50 years or younger that had had macrofocal myocardial infarction, the CC genotype of the A1166C polymorphic marker of gene AT2R1 was associated with an increased risk of CHF (OR = 11.36). Genotype DD and allele D of the I/D polymorphic marker of gene ACE were associated with a more severe CHF (functional class III-IV) in Russian patients (OR = 3.50 and 2.06). In Tatar patients, polymorphic markers I/D of gene ACE and A1166C of gene AT2R1 were not associated with CHF.     

Development of new plasmid DNA vaccine vectors with R1-based replicons

ABSTRACT: BACKGROUND: There has been renewed interest in biopharmaceuticals based on plasmid DNA (pDNA) in recent years due to the approval of several veterinary DNA vaccines, on-going clinical trials of human pDNA-based therapies, and significant advances in adjuvants and delivery vehicles that have helped overcome earlier efficacy deficits. With this interest comes the need for high-yield, cost-effective manufacturing processes. To this end, vector engineering is one promising strategy to improve plasmid production. RESULTS: In this work, we have constructed a new DNA vaccine vector, pDMB02-GFP, containing the runaway R1 origin of replication. The runaway replication phenotype should result in plasmid copy number amplification after a temperature shift from 30degreesC to 42degreesC. However, using Escherichia coli DH5alpha as a host, we observed that the highest yields of pDMB02-GFP were achieved during constant-temperature culture at 30degreesC, with a maximum yield of approximately 19 mg pDNA/g DCW being observed. By measuring mRNA and protein levels of the R1 replication initiator protein, RepA, we determined that RepA may be limiting pDMB02-GFP yield at 42degreesC. A mutant plasmid, pDMB-ATG, was constructed by changing the repA start codon from the sub-optimal GTG to ATG. In cultures of DH5alpha[pDMB-ATG], temperature-induced plasmid amplification was more dramatic than that observed with pDMB02-GFP, and RepA protein was detectable for several hours longer than in cultures of pDMB02-GFP at 42degreesC. CONCLUSIONS: Overall, we have demonstrated that R1-based plasmids can produce high yields of high-quality pDNA without the need for a temperature shift, and have laid the groundwork for further investigation of this class of vectors in the context of plasmid DNA production.     

The Role of Hormones in Fast Growth Responses of Wheat Plants to Osmotic and Cold Shocks

The effects of nutrient-solution cooling and PEG addition to the nutrient solution on the phytohormone content, the rate of leaf growth, leaf extensibility under the influence of external mechanical action, osmotic potential, and transpiration were studied in seven-day-old wheat plants. Leaf growth rapidly ceased, and the transpiration rate was reduced in both treatments. Growth cessation induced by PEG was transient, and growth resumption was preceded by an increase in the leaf extensibility. The functional role of auxin accumulation in plant shoots in the control of extensibility as well as the relationship between the ABA accumulation and a decrease in the cytokinin content, on the one hand, and reduced transpiration, on the other hand, under stress conditions are discussed.     

Mitochondrial DNA structure and colony expansion dynamics of New Zealand fur seals (Arctocephalus forsteri) around Banks Peninsula

New Zealand fur seals are one of many pinniped species that survived the commercial sealing of the eighteenth and nineteenth centuries in dangerously low numbers. After the enforcement of a series of protection measures in the early twentieth century, New Zealand fur seals began to recover from the brink of extinction. We examined the New Zealand fur seal populations of Banks Peninsula, South Island, New Zealand using the mitochondrial DNA control region. We identified a panmictic population structure around Banks Peninsula. The most abundant haplotype in the area showed a slight significant aggregated structure. The Horseshoe Bay colony showed the least number of shared haplotypes with other colonies, suggesting a different origin of re-colonisation of this specific colony. The effective population size of the New Zealand fur seal population at Banks Peninsula was estimated at approximately 2500 individuals. The exponential population growth rate parameter for the area was 35, which corresponds to an expanding population. In general, samples from adjacent colonies shared 4.4 haplotypes while samples collected from colonies separated by between five and eight bays shared 1.9 haplotypes. The genetic data support the spill-over dynamics of colony expansion already suggested for this species. Approximate Bayesian computations analysis suggests re-colonisation of the area from two main clades identified across New Zealand with a most likely admixture coefficient of 0.41 to form the Banks Peninsula population. Approximate Bayesian computations analysis estimated a founder population size of approximately 372 breeding individuals for the area, which then rapidly increased in size with successive waves of external recruitment. The population of fur seals in the area is probably in the late phase of maturity in the colony expansion dynamic.     

Heterometallic complex formation on p-sulfonatothiacalix[4]arene platform resulting in pH- and redox-modification of [Ru(bpy)3] luminescence

The pH-dependent heterometallic complex formation with p-sulfonatothiacalix[4]arene (TCAS) as bridging ligand in aqueous solutions was revealed by the use of spectrophotometry, nuclear magnetic relaxation and fluorimetry methods. The novelty of the structural motif presented is that the appendance of emission metal center ([Ru(bpy)₃]²⁺) is achieved through the cooperative non-covalent interactions with the upper rim of TCAS. The second metal block (Fe(III), Fe(II) and Mn(II)), bound with the lower rim of TCAS in the inner sphere coordination mode is serving as quencher of [Ru(bpy)₃]²⁺ emission. The difference between the complex ability of Fe(III) and Fe(II) ions provides pH conditions for redox-dependent emission of [Ru(bpy)₃]²⁺.     

Genetic isolation and morphological divergence mediated by high-energy rapids in two cichlid genera from the lower Congo rapids

Background  

It is hypothesized that one of the mechanisms promoting diversification in cichlid fishes in the African Great Lakes has been the well-documented pattern of philopatry along shoreline habitats leading to high levels of genetic isolation among populations. However lake habitats are not the only centers of cichlid biodiversity - certain African rivers also contain large numbers of narrowly endemic species. Patterns of isolation and divergence in these systems have tended to be overlooked and are not well understood.     

Functional knock down of VCAM1 in mice mediated by endoplasmatic reticulum retained intrabodies

Functional knockdowns mediated by endoplasmatic reticulum-retained antibodies (ER intrabodies) are a promising tool for research because they allow functional interference on the protein level. We demonstrate for the first time that ER intrabodies can induce a knock-down phenotype in mice. Surface VCAM1 was suppressed in bone marrow of heterozygous and homozygous ER intrabody mice (iER-VCAM1 mice). iER-VCAM1 mice did not have a lethal phenotype, in contrast to the constitutive knockout of VCAM1, but adult mice exhibited physiological effects in the form of aberrant distribution of immature B-cells in blood and bone marrow. The capability to regulate knock-down strength may spark a new approach for the functional study of membrane and plasma proteins, which may especially be valuable for generating mouse models that more closely resemble disease states than classic knockouts do.     

A small molecule that disrupts S. Typhimurium membrane voltage without cell lysis reduces bacterial colonization of mice

As pathogenic bacteria become increasingly resistant to antibiotics, antimicrobials with mechanisms of action distinct from current clinical antibiotics are needed. Gram-negative bacteria pose a particular problem because they defend themselves against chemicals with a minimally permeable outer membrane and with efflux pumps. During infection, innate immune defense molecules increase bacterial vulnerability to chemicals by permeabilizing the outer membrane and occupying efflux pumps. Therefore, screens for compounds that reduce bacterial colonization of mammalian cells have the potential to reveal unexplored therapeutic avenues. Here we describe a new small molecule, D66, that prevents the survival of a human Gram-negative pathogen in macrophages. D66 inhibits bacterial growth under conditions wherein the bacterial outer membrane or efflux pumps are compromised, but not in standard microbiological media. The compound disrupts voltage across the bacterial inner membrane at concentrations that do not permeabilize the inner membrane or lyse cells. Selection for bacterial clones resistant to D66 activity suggested that outer membrane integrity and efflux are the two major bacterial defense mechanisms against this compound. Treatment of mammalian cells with D66 does not permeabilize the mammalian cell membrane but does cause stress, as revealed by hyperpolarization of mitochondrial membranes. Nevertheless, the compound is tolerated in mice and reduces bacterial tissue load. These data suggest that the inner membrane could be a viable target for anti-Gram-negative antimicrobials, and that disruption of bacterial membrane voltage without lysis is sufficient to enable clearance from the host.