Microsatellite markers for Cryptolestes ferrugineus (Coleoptera: Laemophloeidae) and other Cryptolestes species

Cryptolestes ferrugineus (Stephens, 1831) is an important insect pest of stored products. Due to its broad host range, short life cycle, and high reproductive capacity, this species has rapidly colonized temperate and tropical regions around the world. In this study, we isolated 18 novel polymorphic microsatellite loci from an enriched genomic library based on a biotin/streptavidin capture protocol. These loci will be useful tool to better understand the genetic structure and migration patterns of C. ferrugineus throughout the world. The genetic parameters were estimated based on 80 individual C. ferrugineus from two natural populations. The results revealed that 18 loci were different polymorphic levels. The numbers of alleles ranged from 3 to 12, and eleven loci demonstrated polymorphic information contents greater than 0.5. The observed (H O) and expected (H E) heterozygosities ranged from 0.051 to 0.883 and 0.173 to 0.815, respectively. Five locus/population combinations significantly deviated from Hardy-Weinberg equilibrium. We also demonstrated the potential utility of the C. ferrugineus microsatellites as population and species markers for four additional Cryptolestes species.

Chicken and rabbit antibodies against porcine pepsinogen A

Isolated porcine pepsinogen A was used for the preparation of polyclonal rabbit and polyclonal chicken anti-pepsinogen A antibodies. Immunochemical properties of both immunoglobulin fractions were compared. The rabbit anti-serum was further purified using immobilized porcine pepsinogen A on magnetic cellulose beads and the resulting anti-pepsinogen A fraction proved to be applicable for the separation and the determination of porcine pepsinogen A. In contrary, antibodies prepared from chicken eggs by the same way have been found not suitable for the evaluation of the pepsinogen A level. Unexpectedly, the pre-immune fraction of chicken antibodies showed reactivity against porcine pepsinogen A and the affinity separation of specific polyclonal chicken anti-pepsinogen A antibodies on immobilized porcine pepsinogen A did not result in an enrichment of anti-pepsinogen A antibodies.

COI barcode based species-specific primers for identification of five species of stored-product pests from genus Cryptolestes (Coleoptera: Laemophloeidae)

Flat grain beetles of the genus Cryptolestes (Coleoptera: Laemophloeidae) are one of the economically most important stored-product pests which feed on many kinds of agricultural products, especially grains. Nine of more than 40 described Cryptolestes species are recognized as stored-product pests and two of the pest species have a cosmopolitan distribution. Given the rapid growth in global trade of food products, ecological barriers to the spread of pests are easily overcome. Therefore, development of reliable systems for routine quarantine inspection and early infestation detection is vital. In the present study, we established a new rapid and accurate cytochrome c oxidase subunit I-based system for molecular identification of five common stored-product Cryptolestes species, namely, Cryptolestes capensis, Cryptolestes ferrugineus, Cryptolestes pusilloides, Cryptolestes pusillus and Cryptolestes turcicus. Five species-specific primer pairs for traditional uniplex polymerase chain reaction assay are described and their specificity and sensitivity for the identification process is evaluated using larval samples of 12 different populations from three continents (Asia, Europe and North America).

DNA barcoding of five common stored-product pest species of genus Cryptolestes (Coleoptera: Laemophloeidae)

Several species of the genus Cryptolestes Ganglbauer, 1899 (Coleoptera: Laemophloeidae) are commonly found in stored products. In this study, five species of Cryptolestes, with almost worldwide distribution, were obtained from laboratories in China, Czech Republic and the USA: Cryptolestes ferrugineus (Stephens, 1831), Cryptolestes pusillus (Schönherr, 1817), Cryptolestes turcicus (Grouvelle, 1876), Cryptolestes pusilloides (Steel & Howe, 1952) and Cryptolestes capensis (Waltl, 1834). Molecular identification based on a 658 bp fragment from the mitochondrial DNA cytochrome c oxidase subunit I (COI) was adopted to overcome some problems of morphological identification of Cryptolestes species. The utility of COI sequences as DNA barcodes in discriminating the five Cryptolestes species was evaluated on adults and larvae by analysing Kimura 2-parameter distances, phylogenetic tree and haplotype networks. The results showed that molecular approaches based on DNA barcodes were able to accurately identify these species. This is the first study using DNA barcoding to identify Cryptolestes species and the gathered DNA sequences will complement the biological barcode database.

Monodisperse carboxyl-functionalized poly(ethylene glycol)-coated magnetic poly(glycidyl methacrylate) microspheres: application to the immunocapture of β-amyloid peptides

Identification and evaluation of small changes in β-amyloid peptide (Aβ) levels in cerebrospinal fluid is of crucial importance for early detection of Alzheimer's disease. Microfluidic detection methods enable effective preconcentration of Aβ using magnetic microparticles coated with Aβ antibodies. Poly(glycidyl methacrylate) microspheres are coated with α-amino-ω-methoxy-PEG5000 /α-amino-ω-Boc-NH-PEG5000 Boc groups deprotected and NH2 succinylated to introduce carboxyl groups. Capillary electrophoresis with laser-induced fluorescence detection confirms the efficient capture of Aβ 1-40 peptides on the microspheres with immobilized monoclonal anti-Aβ 6E10. The capture specificity is confirmed by comparing Aβ 1-40 levels on the anti-IgG-immobilized particles used as a control.

Size exclusion chromatography as a tool for evaluation of fragmentation pattern of gastric mucins under non-degrading conditions

Gastric mucins are high molecular weight extracellular glycoproteins that play a major role in the protection of the gastrointestinal tract and besides that they are also involved in many disease processes. In the present study, size exclusion chromatography under non-degrading conditions was used to study the fragmentation pattern of native gastric mucins. The samples of gastric mucins of different origin obtained by an extraction of gastric mucosa with Tris-HCl buffer, pH 7.3 were separated using size exclusion chromatography on Sephadex G-100. While samples of rat gastric mucins are characterized by the presence of only high-molecular weight fraction of glycoproteins, fragmented mucin components in non-denaturated samples were observed in canine and human gastric mucins. Differences in the fragmentation pattern were observed in patients with ulcer diseases and gastric cancer. Degradation products of mucins were also detected using polyacrylamide gel electrophoresis in the presence of SDS.

Peptide Maps of Porcine Pepsin Prepared Using Soluble and Immobilized α-Chymotrypsin

Reverse-phase high performance liquid chromatography (RP-HPLC) was used for characterization of peptide maps of porcine pepsin using soluble or immobilized α-chymotrypsin. The immobilized enzyme was prepared by its coupling to periodate-oxidized poly(acrylamide-co-allyl α-D-galactoside or allyl β-lactoside) copolymer (O-glycosylated acrylamide copolymer). After sodium cyanoborohydride reduction, a stable linkage was formed. Specific activity of α-chymotrypsin, linked to the copolymer containing bound α-D-galactosyl or β-lactosyl residues was 59.1 or 314.4% activity of soluble enzyme.