Other P-types have been delineated by RT-PCR and sequencing (P-genotypes), and, unfortunately, P-geno-types do not correspond to serotype designations. VP8* carries the P-specific epitopes whereas VP5* epitopes are cross-reactive. There are 20 different P-genotypes and 12-15 P-serotypes (Table 3). Infection with one P-type does not necessarily protect against infection with the others. By convention P-genotypes are designated by a number in a squared bracket.

VP7 is the major neutralization antigen and comprises 30% of protein in the mature virion. It forms the smooth surface of the outer capsid through which the VP4 knobs protrude. It is a glycoprotein containing N-linked high-mannose oligosaccharides. It is encoded on the seventh, eight, or ninth segment depending upon the rotavirus strain. Its role in viral replication is unclear. Currently, 14 G-serotypes have been defined by use of neutralizing monoclonal antibodies and by RT-PCR. Fortunately, the G-serotypes and G-genotypes coincide (Table 4). Within a particular G-genotype the deduced amino acid sequences are 91-100% similar, but between genotypes the differences are significantly greater. Most of the divergence is represented in nine regions of VP7. Of the variable regions (VR), VR5 (aa 87-101), VR7 (aa 142-152), and VR8 (aa 208-221) are the major neutralization epitopes and escape mutants with point mutations in these regions occur easily.[10] Infection with one genotype does not necessarily impart protection against others.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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