Characterization of two closely related α‐amylase paralogs in the bark beetle, Ips typographus (L.)

Abstract

Ips typographus (L.), the eight-spined spruce bark beetle, causes severe damage throughout Eurasian spruce forests and suitable nuclear markers are needed in order to study its population structure on a genetic level. Two closely related genes encoding a-amylase in I. typographus were characterized and named AmyA and AmyB. Both a-amylase paralogs consisted of six exons and five introns. AmyA encodes a polypeptide of 483 amino acids, whereas AmyB has two alternative transcripts encoding polypeptides of 483 and 370 amino acids. The expression levels of both genes were high during larval stage and adulthood. The AmyB transcripts were absent in the pupal stage. A modification of the allozyme staining method allowed us to detect two clusters of bands on the electrophoretic gel that may correspond to the two a-amylase genes. There was a correlation between the lack of AmyB expression in pupa and the absence of the fast migrating isozyme cluster at this stage, suggesting that the faster migrating isoforms are products of the AmyB gene, whereas the slowly migrating bands are derived from the AmyA. C 2011 Wiley Periodicals, Inc.

The Bark Beetle Dendroctonus rhizophagus (Curculionidae: Scolytinae) Has Digestive Capacity to Degrade Complex Substrates: Functional Characterization and Heterologous Expression of an α-Amylase

“…In silico analysis showed that this protein has a 51.51 kDa molecular mass (without signal peptide), similar to the α-amylase from other scolytines, such as D. ponderosae ( Cosmopolites sordidus (AKN63428.1). However, this result is different from those found in A. grandis, I. typographus, and Rhynchophorus ferrugineus in which two Amy genes have been documented [25,28,29]. Based on the number of α-amylases genes (from 1 to 9) in Coleoptera [23], as well as on the bioinformatics analyses of transcriptomes and genomes from Dendroctonus species studied so far, the genus Dendroctonus presented the lowest number of α-amylases genes.…”

“…Studies in population genetics have demonstrated the presence of allelic variants of these enzymes [24]. However, Viktorinova et al [25] demonstrated in I. typographus the presence of two α-amylase genes one of them producing two isoforms as a result of alternative splicing.…”

Inhibitory effects of plant extracts on growth, development and α-amylase activity in the red flour beetle Tribolium castaneum (Coleoptera: Tenebrionidae)

“…Similar stage-specific expression is recorded in I. typographus (Viktorinova et al, 2011) and H. armigera (Kotkar et al, 2012), indicating that the expression of the amylase gene may be connected to feeding. In T. castaneum, the developmental change in α-amylase activity may be primarily caused by stage-specific TmAmy expression.…”

“…Developmental stage-specific changes in enzymatic activity are reported as occurring in the confused flour beetle, Tribolium confusum (Bandani & Balvasi, 2006), larger grain borer, Prostepanus truncatus (Mediola-Olaya et al, 2000), bark beetle, Ips typographus (Viktorinova et al, 2011) and cotton bollworm, Helicoverpa armigera (Kotkar et al, 2009). In these species, high activity during the larval and adult stages and low activity during the prepupal period are commonly recorded.…”

Caracterización de la actividad amilásica presente en extractos larvarios de dos polillas plagas de la papa: Tecia solanivora y Symmetrischema tangolias

“…La alimentación voraz de las polillas en su estado larvario, provoca considerables daños que se observan a simple vista en el tubérculo, por lo cual asumimos que cada estadio despliega diferentes grados de actividad enzimática, acompañada de cambios proteicos estructurales y funcionales que se identifican con el modelo de infestación. Algunas clases de insectos tienen una dieta rica en almidones los cuales deben ser procesados por enzimas como las amilasas (Kotkar et al, 2012;Viktorinova et al, 2011;). La a-amilasa (alfaamilasa 1.4-glucan-4-glucanoanhidrasa), ha sido descrita en los órdenes: Diptera, Coleoptera, Hymenoptera, Lepidoptera y Hemiptera y tiene la función de catalizar la hidrólisis de las uniones a-1.4 glucosídicas (Darvishzadeh et al, 2012;Ngernyuang et al, 2010;Kazzazi et al, 2005;Baker, 1983…”