Date of Graduation


Document Type


Degree Type



Davis College of Agriculture, Natural Resources and Design


Animal and Nutritional Sciences

Committee Chair

Wei-Shau Hu.


Specific encapsidation of viral RNA is an essential step of retroviral replication cycle. Extensive biochemical and genetic analyses suggest that majority of retroviruses employ similar mechanisms for specific RNA packaging. Better understanding of mechanisms of this process may help to develop new anti-retroviral drugs against such serious pathogens as human immunodeficiency virus types 1 and 2.;This study concerns with specific packaging of RNA by two simple retroviruses, murine leukemia virus (MLV) and spleen necrosis virus (SNV). SNV proteins can package RNA of both SNV and MLV with similar efficiency. In contrast, MLV proteins cannot package SNV RNA. NC domain was shown to be the determinant of nonreciprocal RNA recognition by these two viruses.;This study was intended to determine biological activities of previously generated MLV- and SNV-derived Gag-Pol chimeras that retained ability to specifically package viral RNA, but rendered viruses non-infectious. We investigated the role of Cys-His box and basic amino acids in non-reciprocal RNA packaging. Also, we examined contribution of single amino acids within Cys-His box to RNA selectivity of viral proteins. Series of MLV- and SNV-derived Gag-Pol chimera expression constructs with exchanged NC fragments or single amino acids were made. They were tested for non-reciprocal RNA packaging.