Concentration of acrylamide in a polyacrylamide gel affects VP4 gene coding assignment of group A equine rotavirus strains with P[12] specificity

To determine which genome segment of three group A equine rotavirus strains (H-2, FI-14 and FI-23) with P[12] specificity encodes the VP4, we analyzed dsRNAs of strains H-2, FI-14 and FI-23 as well as their reassortants by polyacrylamide gel electrophoresis (PAGE) at varying concentrations of acrylamide. The relative position of the VP4 gene of the three equine P[12] strains varied (either genome segment 3 or 4) depending upon the concentration of acrylamide. The VP4 gene bearing P[3], P[4], P[6], P[7], P[8] or P[18] specificity did not exhibit this phenomenon when the PAGE running conditions were varied.The concentration of acrylamide in a PAGE gel affected VP4 gene coding assignment of equine rotavirus strains bearing P[12] specificity.Diarrheal disease is one of the principal causes of morbidity and mortality among young children in the developing world. Infectious diarrhea of neonatal animals is also one of the most common and economically devastating conditions encountered in the animal agriculture industry. Among an array of infectious agents including bacteria, viruses and parasites, group A rotaviruses are the single most important etiologic agents of diarrhea in infants and young children worldwide and in addition, they are the most commonly identified viral cause of diarrhea in neonatal food animals [1-4]. In 1975, rotaviruses were first demonstrated being involved in foal diarrhea [5], and later established as the major cause of diarrhea in young foals [6-8].The genome of group A rotavirus, a member of Reoviridae family, consists of eleven segments of double-stranded RNA numbered 1-11 according to their order of migration in polyacrylamide gels, segment 1 being the slowest and segment 11 the fastest [9]. The rotavirus genome encodes six structural (VP1-VP4, VP6 and VP7) and six nonstructural (NSP1-NSP6) proteins [3]. Since two outer capsid proteins VP7 and VP4 are independent neutralization and protective antigens, a binary system of classification and no