Previous studies showed that unilateral denervation (DNV) of the rat diaphragm muscle (DIAm) results in loss of myosin heavy chain protein by 1 day after DNV. We hypothesize that DNV decreases net protein balance as a result of activation of the ubiquitin-proteasome pathway. In DIAm strips, protein synthesis was measured by incorporation of 3H-Tyr, and protein degradation was measured by Tyr re...

The silkworm, Bombyx mori is infected by a number of viruses: Bombyx mori nuclear polyhedrosis virus (BmNPV), cytoplasmic polyhedrosis virus (CPV), infectious flacherie virus (IFV) and densonucleosis virus (DNV). Except DNV, resistance of silkworms to the virus is controlled by polygenes. Serologically, two DNV types, DNV-1 and DNV-2 are identified. The non-susceptibility to DNV types is confer...

Among the infectious densonucleosis virus (DNV) particles, two types of virions, DNV-I and DNV-II, have been identified. The density of DNV-I was about 1.40 g/ml and depended on the pH, whereas the density of DNV-II was independent of the pH and was 1.44 g/ml. The sedimentation rates of these particles were 111S and 89S, respectively. The specific extinction coefficients and the absorption spec...

Although prolonged diaphragm denervation (DNV) produces myofiber atrophy and a loss of type I myosin heavy chain (MHC) expression, short-term DNV leads to significant diaphragm hypertrophy. The purpose of this study was to explore the regulation of MHC isoform expression and muscle remodeling during DNV hypertrophy of the diaphragm. Both unilateral and bilateral DNV led to similar changes, with...

Screening for densoviruses (DNVs) from Aedes, Culex and Toxorhynchites mosquitoes collected in Bangkok and surrounding regions identified two clades of Aedes DNV; Ae. aegypti DNV (AaeDNV) and Ae. albopictus DNV (AalDNV) by PCR-restriction fragment length polymorphism (PCR-RFLP). From nucleotide sequencing and phylogenetic analysis of PCR amplicons of a fragment of DNV capsid gene, these DNVs we...

In the silkworm (Bombyx mori), resistance to the Zhenjiang (China) strain of the densonucleosis virus (DNV-Z) is controlled by the recessive gene nsd-Z (non-susceptible to DNV-Z), which is linked to 7 simple-sequence repeat markers. Marker-assisted evaluation and selection of DNV-Z-resistant silkworms were used for predicting DNV-resistance in backcrossed animals. A silkworm race was bred using...

Unilateral denervation (Dnv) of the rat diaphragm muscle (Diam) markedly alters expression of myosin heavy chain (MHC) isoforms. After 2 wk of Diam Dnv, MHC content per half-sarcomere decreases in fibers expressing MHC(2X) and MHC(2B). We hypothesized that changes in MHC protein expression parallel changes in MHC mRNA expression. Relative MHC isoform mRNA levels were determined by Northern anal...

Denervation (DNV) of rat diaphragm muscle (DIAm) leads to selective atrophy of type IIx and IIb fibers, whereas the cross-sectional area of type I and IIa fibers remains unchanged or slightly hypertrophied. DIAm DNV also increases satellite cell mitotic activity and myonuclear apoptosis. Similar to other skeletal muscles, DIAm fibers are multinucleated, and each myonucleus regulates the gene pr...

Denervation (DNV) of rat diaphragm muscle (DIAm) decreases myosin heavy chain (MHC) content in fibers expressing MHC(2X) isoform but not in fibers expressing MHC(slow) and MHC(2A). Since MHC is the site of ATP hydrolysis during muscle contraction, we hypothesized that ATP consumption rate during maximum isometric activation (ATP(iso)) is reduced following unilateral DIAm DNV and that this effec...

We hypothesize that 1) the effect of denervation (DNV) is more pronounced in fibers expressing fast myosin heavy chain (MHC) isoforms and 2) the effect of DNV on maximum specific force reflects a reduction in MHC content per half sarcomere or the number of cross bridges in parallel. Studies were performed on single Triton X-100-permeabilized fibers activated at a pCa (-log Ca2+ concentration) o...