Changes After Immunization in the Hybridization of Mouse Spleen RNA And Reiterative DNA

Abstract

RNA from the spleens of imnunized and nonimmunized mice was hybridized with purified reiterative DNA fran the mouse livers under conditions in which hybrids preferentially formed with nucleotide sequences extensively reiterated (low Cot). Hybrids of mouse spleen RNA and reiterative DNA were detected. Three days after the injection of sheep RBC, the proportion of RNA in excess which hybridized with reiterative DNA was 70 percent less than the proportion of hybridizable RNA from mice not injected with antigen. A qualitative change in RNA synthesis in the spleen was detected after mice were injected with different antigens. RNA formed in response to sheep RBC was distinguishable from RNA formed in response to E. coli. The RNA used in these experiments was not fractionated and undoubtedly contained numerous species of RNA involved in many phases of the response of spleen cells to antigen exposure.