Biological control of Strophosoma spp. (Coleoptera: Curculionidae) in greenery (Abies procera) plantations using Hyphomycetes

In Abies procera plantations Strophosoma melanogrammum and S. capitatum cause economic damage due to the adult stage feeding on the needles. No chemical treatments of these weevils are allowed in Denmark, so the potential of biological control was evaluated. We studied pathogenicity of thirteen isolates of entomopathogenic fungi and the field effect of soil application of Metarhizium anisopliae against Strophosoma spp. All of the tested isolates were capable of causing infections under laboratory conditions and average survival time at 20°C ranged between 13 and 23 days for S. melanogrammum and between 23 and 28 days for S. capitatum when dipped in a fungal suspension adjusted to 1×10⁷ conidia mL^-1. Under field conditions up to 90% of the living collected individuals died due to M. anisopliae infection in the treated plots, whereas less than 1% died of M. anisopliae infection in control plots. In accordance, the population of Strophosoma spp. was reduced in plots where the fungus was applied compared to control plots.     

Structural and functional analysis of the PDZ domains of human HtrA1 and HtrA3

High-temperature requirement A (HtrA) and its homologs contain a serine protease domain followed by one or two PDZ domains. Bacterial HtrA proteins and the mitochondrial protein HtrA2/Omi maintain cell function by acting as both molecular chaperones and proteases to manage misfolded proteins. The biological roles of the mammalian family members HtrA1 and HtrA3 are less clear. We report a detailed structural and functional analysis of the PDZ domains of human HtrA1 and HtrA3 using peptide libraries and affinity assays to define specificity, structural studies to view the molecular details of ligand recognition, and alanine scanning mutagenesis to investigate the energetic contributions of individual residues to ligand binding. In common with HtrA2/Omi, we show that the PDZ domains of HtrA1 and HtrA3 recognize hydrophobic polypeptides, and while C-terminal sequences are preferred, internal sequences are also recognized. However, the details of the interactions differ, as different domains rely on interactions with different residues within the ligand to achieve high affinity binding. The results suggest that mammalian HtrA PDZ domains interact with a broad range of hydrophobic binding partners. This promiscuous specificity resembles that of bacterial HtrA family members and suggests a similar function for recognizing misfolded polypeptides with exposed hydrophobic sequences. Our results support a common activation mechanism for the HtrA family, whereby hydrophobic peptides bind to the PDZ domain and induce conformational changes that activate the protease. Such a mechanism is well suited to proteases evolved for the recognition and degradation of misfolded proteins.     

DTPA soil extractable and plant heavy metal concentrations with soil-added Cd treatments

Summary The numbers, weights, and ages of root nodules were determined in a homogeneous 6- to 7-year-old stand ofHippophaë rhamnoides in a coastal sand-dune area. Large variations in the number of nodules, which ranges from 30 to 281 per m² were found. Most of the nodules occurred between 10 and 60 cm below the soil surface. In the surface layer and lower than 60 cm only small numbers of nodules were present. It is concluded that relatively large samples have to be investigated to obtain an impression of the nodulation of a given stand and to permit a comparison of the contribution of dinitrogen fixation in different stands.Close correlation was found between nodule numbers and the age of the roots, young roots having the highest numbers. However, the wide variation in the number of nodules per square metre could not be explained solely by the age distribution of the roots. The possible role of some other factors is discussed. No relationship was found between the nodule weight and the age of the nodule. The mean dry weight of living nodule material was 5.3 g per m². Most nodules reached an age of up to 3 years. The significance of nodule decay for the distribution of the endophyte in the soil and in the process of nodule formation is discussed.     

Determination of isotope ratios in human tissues enriched with zinc stable isotope tracers using inductively coupled plasma-mass spectrometry (ICP-MS)

Enriched fecal and urine samples were prepared using ion-exchange column chromatography for analysis by Inductively Coupled and Fast Atom Bombardment Mass spectrometry (ICP-MS, FAB-MS) to compare precision between methods. Unenriched samples of human milk, feces, and whole blood were prepared similarly to monitor instrumental precision and analytical error. A least squares fit of the ICP-MS results vs the FAB-MS for⁷⁰Zn/⁶⁴Zn gave a slope of 0.98, with a relative standard deviation (RSD) of only 0.7%. The results for⁶⁸Zn/⁶⁴Zn gave a slope of 0.82, with a RSD of 14%. For unenriched tissues, all potential interferences were removed by the preparation procedure with no significant differences between preparation for isotope ratios of⁷⁰Zn/⁶⁴Zn,⁶⁸Zn/⁶⁴Zn,⁶⁷Zn/⁶⁴Zn, and⁶⁶Zn/⁶⁴Zn. Poisson counting statistics are a major contribution to the total analytical error indicating the usefulness of this procedure for enrichment studies.     

Interendothelial junctions of cardiac capillaries in rats: their structure and permeability properties

Summary The isolated perfused heart model was used to examine the structure of rat cardiac capillaries and their permeability to macromolecules of various sizes. Haemoglobin (diameter 6.4 nm) and catalase (10.4 nm) did not cross the endothelium but remained on the luminal side. Cytochrome C (3 nm) and horseradish peroxidase (6 nm) both crossed the endothelium to the subendothelial space and filled the caveolae on the abluminal side as well as the entire length of the lateral intercellular spaces. The membranes of the endothelial cells are separated by an intercellular gap of mean width 18.2 nm. At one or more zonular regions within each lateral intercellular space the two membranes approach each other more closely and frequently appear to fuse. However, tilting the specimen shows that, in these regions, there is a gap of mean width 5.4 nm (in lanthanum- and tannic acid-treated tissue, 3.8 nm in ferrocyanide-treated tissue) between the membranes. We conclude that these narrow regions sieve macromolecules on the basis of size although other factors may determine their permeability properties.     

Serum and tissue alkaline phosphatases in pigs*

The alkaline phosphatases from serum, liver, bone and intestine of pigs were separated by starch and polyacrylamide gel electrophoresis. Treatments with neuraminidase, urea, heat, L-homoarginine and L-phenylalanine were performed. Variants of serum alkaline phosphatases were derived from different tissues and hence must be under the control of at least two different loci. Within the intestinal phosphatases, polymorphic electrophoretic patterns were observed among 195 animals.     

Genetic control of geographic variation for cannibalism in the southwestern corn borer,Diatraea grandiosella

The southwestern corn borer,Diatraea grandiosella Dyar, is a subtropical insect whose range has expanded northward within this century. Geographic variation exists between populations at the extremes of the range for a suite of morphological and behavioral characters, including cannibalism. Laboratory colonies established from a Missouri population (37°N lat.) with a high cannibalism rate and a Mexican population (19° N lat.) with a low cannibalism rate were used to examine the genetic basis of cannibalism by means of a controlled breeding design. When larvae were held in pairs on artificial diet in 30 ml plastic cups at 30° C 16L:8D, the highest incidence of cannibalism in both Missouri and Mexican populations was found in larvae 15 to 18 days-of-age (5th and 6th instars). Under these conditions, cannibalism was expressed in 33% of the pairs formed from Missouri larvae and 11% of the pairs formed from Mexican larvae. First and second generation crosses between Missouri and Mexican populations showed an intermediate level of cannibalism, whereas backcrosses to the parental generations showed a regression to the parental phenotypes. These results indicate that cannibalism is under additive genetic control. Larvae from the Missouri parental population were more likely to consume their victim (i.e., cannibalize) once intraspecific killing had occurred than were larvae from the Mexican parental population or from any of the crosses, and female larvae were cannibals more often than were males. Under the conditions employed, no advantage was detected for cannibalism over instraspecific killing for larval weight gain or growth rate.     

Role of genomics in translational research for Parkinson’s disease

Research on Parkinson’s disease (PD) has made remarkable progress in recent decades, due largely to new genomic technologies, such as high throughput sequencing and microarray analyses. Since the discovery of a linkage of a missense mutation of the α-synuclein (αS) gene to a rare familial dominant form of PD in 1996, positional cloning and characterization of a number of familial PD risk factors have established a hypothesis that aggregation of αS may play a major role in the pathogenesis of PD. Furthermore, dozens of sensitizing alleles related to the disease have been identified by genome wide association studies (GWAS) and meta-GWAS, contributing to a better understanding of the pathological mechanisms of sporadic PD. Thus, the knowledge obtained from the association studies will be valuable for “the personal genome” of PD. Besides summarizing such progress, this paper focuses on the role of microRNAs in the field of PD research, since microRNAs might be promising as a biomarker and as a therapeutic reagent for PD. We further refer to a recent view that neurodegenerative diseases, including PD, coexist with metabolic disorders and are stimulated by type II diabetes, the most common disease among elderly populations. The development of genomic approaches may potentially contribute to therapeutic intervention for PD.     

Isolation and characterisation of a new mosquitocidal bacterium strain of Enterobacter cloacae VCRC-B519 from marine soil

A novel mosquitocidal bacterium was isolated from marine soil. 16S rRNA gene sequence alignment depicted that this isolate belonged to the strain, Enterobacter cloacae VCRC-B519 (NCBI: KC119193). Biochemical studies such as bacterial growth, biomass production and protein (toxin) synthesis showed that the strain is plausibly useful for mosquito control. It showed an increasing pattern of toxicity for Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti, without negative effects for non-targeted organisms Chironomus riparius, Daphnia cephalata and Notonecta glauca. The qualitative analysis of the E. cloacae showed that three polypeptides (M.wt: 25, 30 and 50 kDa) were associated to the toxicity observed. The characterisation of these polypeptides (M/S MALDI-TOF)showed that they are enzymatic in nature. Consequently, the peptide sequences are identified to be polysugar degrading enzymes (25 kDa), cell wall associated hydrolases (30 kDa) and amino peptidase (50 kDa). Phylogenetic analyses of 16S rDNA gene sequence of E. cloacae revealed the occurrence of homology with closely related Enterobacter species. Therefore, it is concluded that the marine bacterium (Enterobacter cloacae)is possibly of use for the biological control of mosquito immatures.