Transgenic organisms expressing genes from Bacillus thuringiensis to combat insect pests

Various subspecies (ssp.) of Bacillus thuringiensis (Bt) are considered the best agents known so far to control insects, being highly specific and safe, easily mass produced and with long shelf life.1 The para-crystalline body that is produced during sporulation in the exosporium includes polypeptides named δ-endotoxins, each killing a specific set of insects. The different entomopathogenic toxins of various Bt ssp. can be manipulated genetically in an educated way to construct more efficient transgenic bacteria or plants that express combinations of toxin genes to control pests.2 Joint research projects in our respective laboratories during the last decade demonstrate what can be done by implementing certain ideas using molecular biology with Bt ssp. israelensis (Bti) as a model system. Here, we describe our progress achieved with Gram-negative bacterial species, including cyanobacteria, and some preliminary experiments to form transgenic plants, mainly to control mosquitoes (Diptera), but also a particular Lepidopteran and Coleopteran pest species. In addition, a system is described by which environment-damaging genes can be removed from the recombinants thus alleviating procedures for obtaining permits to release them in nature.     

Concentration- and time-dependent effects of enoxaparin on human adenocarcinomic epithelial cell line A549 proliferation in vitro

Non-small cell lung cancer (NSCLC) is a major health problem. Surgery is the only potential curative treatment, in spite of the high recurrence and mortality rates. Low molecular weight heparins (LMWH) have been suggested to have a positive impact on the outcome of various cancers, mainly attributed to their anticoagulant properties; yet a direct antineoplastic effect has not been excluded. We thought to evaluate the direct effect of the LMWH enoxaparin on the human lung adenocarcinomic epithelial cell line A549 and to determine potential antiproliferative and antimetastatic effects that could guide future trials. A549 cells were cultured with different concentrations of enoxaparin (1-30 U/mL). Cell counting was performed at 24, 48, and 72 h. Detection of c-Myc protein and CD44 protein was performed by electrophoresis and Western blotting. Statistical analysis was performed using paired Student's t tests. Cell counts were decreased with increasing concentrations and time of exposure to enoxaparin. This corresponds to decreased expression of c-Myc and CD44. In conclusion, enoxaparin displayed a direct dose and exposure duration dependent suppressor effect on A549 cell proliferation and the expression of both c-Myc and CD44 in vitro, suggesting reduced proliferative and metastatic potentials of these cells.     

Arthritis patterns in familial Mediterranean fever patients and association with M694V mutation

Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent attacks of febrile peritonitis, pleuritis and synovitis. Arthritis is a common and important feature of FMF. The clinical spectrum of arthritis in 71 FMF patients was retrospectively investigated. Mutations in the familial Mediterranean (MEFV) gene were screened. Unlike the previous reports on arthritis of FMF, most of the FMF patients (59%) in this study had symmetric two-joint arthritis whereas monoarticular, oligoarticular and polyarticular arthritis was presented in 20, 8 and 10% of the patients, respectively. Knees were affected in 45 (63%) patients, ankles in 30 (42%), elbows in 11 (15%), wrists in 12 (17%), hips in 12 (17%), small joints of the hands 7 (10%), small joints of the feet 2 (3%) and sacroiliac in 1 (1%). Destruction of the hip was observed in 2 (3%) patients and required hip replacement. Amyloidosis developed in 2 (3%) of our patients. Mutations in the MEFV gene were identified in 50 (71%) patients and the most dominant mutation detected was M694V (64%). Since FMF can be diagnosed by a simple DNA mutation analysis, all arthritis patients of certain origins (Arabs, Turks, Armenians and Jews) should be tested for FMF in order to prevent the complications (amyloidosis and protracted arthritis) by introducing colchicine which is the treatment of choice for FMF.     

Molecular evolution of Dmrt1 accompanies change of sex-determining mechanisms in reptilia

In reptiles, sex-determining mechanisms have evolved repeatedly and reversibly between genotypic and temperature-dependent sex determination. The gene Dmrt1 directs male determination in chicken (and presumably other birds), and regulates sex differentiation in animals as distantly related as fruit flies, nematodes and humans. Here, we show a consistent molecular difference in Dmrt1 between reptiles with genotypic and temperature-dependent sex determination. Among 34 non-avian reptiles, a convergently evolved pair of amino acids encoded by sequence within exon 2 near the DM-binding domain of Dmrt1 distinguishes species with either type of sex determination. We suggest that this amino acid shift accompanied the evolution of genotypic sex determination from an ancestral condition of temperature-dependent sex determination at least three times among reptiles, as evident in turtles, birds and squamates. This novel hypothesis describes the evolution of sex-determining mechanisms as turnover events accompanied by one or two small mutations.     

A comparison of dorsal and heel plate foot tracking methods on lower extremity dynamics

The primary method to model ankle motion during inverse dynamic calculations of the lower limb is through the use of skin-mounted markers, with the foot modeled as a rigid segment. Motion of the foot is often tracked via the use of a marker cluster triad on either the dorsum, or heel, of the foot/shoe. The purpose of this investigation was to evaluate differences in calculated lower extremity dynamics during the stance phase of gait between these two tracking techniques. In an analysis of 7 subjects, it was found that sagittal ankle angles and sagittal ankle, hip and knee moments were strongly correlated between the two conditions, however, there was a significant difference in peak ankle plantar flexion and dorsiflexion angles. Frontal ankle angles were only moderately correlated and there was a significant difference in peak ankle eversion and inversion, resulting in moderate correlations in frontal plane moments and a significant difference in peak hip adductor moments. We demonstrate that the technique used to track the foot is an important consideration in interpreting lower extremity dynamics for clinical and research purposes.     

Endothelial Semaphorin 3fb regulates Vegf pathway-mediated angiogenic sprouting

Vessel growth integrates diverse extrinsic signals with intrinsic signaling cascades to coordinate cell migration and sprouting morphogenesis. The pro-angiogenic effects of Vascular Endothelial Growth Factor (VEGF) are carefully controlled during sprouting to generate an efficiently patterned vascular network. We identify crosstalk between VEGF signaling and that of the secreted ligand Semaphorin 3fb (Sema3fb), one of two zebrafish paralogs of mammalian Sema3F. The sema3fb gene is expressed by endothelial cells in actively sprouting vessels. Loss of sema3fb results in abnormally wide and stunted intersegmental vessel artery sprouts. Although the sprouts initiate at the correct developmental time, they have a reduced migration speed. These sprouts have persistent filopodia and abnormally spaced nuclei suggesting dysregulated control of actin assembly. sema3fb mutants show simultaneously higher expression of pro-angiogenic (VEGF receptor 2 (vegfr2) and delta-like 4 (dll4)) and anti-angiogenic (soluble VEGF receptor 1 (svegfr1)/ soluble Fms Related Receptor Tyrosine Kinase 1 (sflt1)) pathway components. We show increased phospho-ERK staining in migrating angioblasts, consistent with enhanced Vegf activity. Reducing Vegfr2 kinase activity in sema3fb mutants rescues angiogenic sprouting. Our data suggest that Sema3fb plays a critical role in promoting endothelial sprouting through modulating the VEGF signaling pathway, acting as an autocrine cue that modulates intrinsic growth factor signaling.     

Long-distance seed dispersal, clone longevity and lack of phylogeographical structure in the European distributional range of the coastal Calystegia soldanella (L.) R. Br. (Convolvulaceae)

Aim  To explore the relative effects of Quaternary climatic history vs. species-specific biological properties (high seed dispersability, high seed longevity, clonal growth) on phylogeographical structure in European Mediterranean and Atlantic Ocean and Black Sea material of the coastal dune plant Calystegia soldanella (L.) R. Br.
Location  Black Sea and European Mediterranean and Atlantic Ocean coasts.
Methods  Variation in amplified fragment length polymorphism was analysed at two different sampling levels. First, an entire-range sample from the Black Sea to the North Sea, including single individuals from sites evenly spread along this entire coast was analysed. Second, in a population-level sample, seven populations from the European Mediterranean and Atlantic Ocean coasts were analysed.
Results  Neither the entire-range nor the population-level sampling resulted in clear phylogeographical patterns. Instead, individuals from geographically distant areas were often genetically more similar to each other than individuals from the same area. Non-significant isolation-by-distance was found for both sampling approaches, and comparatively low levels of intrapopulational genetic variation were observed.
Main conclusions  The lack of phylogeographical structure in C. soldanella , in comparison with the clear phylogeographical patterns observed in other coastal plant species analysed previously, is postulated to be the result of the specific biology of C. soldanella . The combination of high seed longevity, high dispersability of seeds by sea water and clonal growth and probable high clone age are likely to be responsible for the observed absence of phylogeographical structure. This implies that extreme biological properties such as those shown by C. soldanella can either erase or prevent the formation of historical patterns of genetic variation.     

The immunomodulatory sphingosine 1-phosphate analog FTY720 reduces lesion size and improves neurological outcome in a mouse model of cerebral ischemia

Cerebral ischemia is accompanied by fulminant cellular and humoral inflammatory changes in the brain which contribute to lesion development after stroke. A tight interplay between the brain and the peripheral immune system leads to a biphasic immune response to stroke consisting of an early activation of peripheral immune cells with massive production of proinflammatory cytokines followed by a systemic immunosuppression within days of cerebral ischemia that is characterized by massive immune cell loss in spleen and thymus. Recent work has documented the importance of T lymphocytes in the early exacerbation of ischemic injury. The lipid signaling mediator sphingosine 1-phosphate-derived stable analog FTY720 (fingolimod) acts as an immunosuppressant and induces lymphopenia by preventing the egress of lymphocytes, especially T cells, from lymph nodes. We found that treatment with FTY720 (1 mg/kg) reduced lesion size and improved neurological function after experimental stroke in mice, decreased the numbers of infiltrating neutrophils, activated microglia/macrophages in the ischemic lesion and reduced immunohistochemical features of apoptotic cell death in the lesion.