Biological and Molecular Biological Characterization of the Virus Progeny from Transformed Clones MuSV-124 and MuSV-349: Evidence for MuLV-specific Nucleotide Sequences in the MoMuSV Size Class of RNA from MoMuSV-124

Abstract

SUMMARYThe genetic information of MoMuSV-349 and MoMuSV-I24, two clones of productively transformed TB cells, was distributed between two size classes of RNA (tool. wt. 2-9 × IO 6 and I'9 × I@) in the proportions of 5: 1. Some preparations of MoMuSV-I24 lacked the large RNA. The virions produced by both clones also contained all the nucleotide sequences of Moloney leukaemia virus and the ratio of MuSV:MuLV produced by the two clones differed markedly. The distribution of the sequences specific for Moloney murine leukaemia virus (MoMuLV) between the two size classes of RNA was studied using molecular hybridization to DNA probes complementary to and representative of: (i) the Moloney murine sarcoma virus (MoMuSV) RNA genome (tool. wt. I'9 × t@); (ii) those nucleotide sequences shared by MoMuSV and MoMuLV; (iii) nucleotide sequences specific for MoMuSV; (iv) nucleotide sequences specific for MoMuLV. The only detectable Moloney leukaemia virus-specific nucleotide sequences present in MoMuSV-I24 virions were in the RNA of tool. wt. 1"9 x lO ~, whereas these sequences were detected in the RNA of mol. wt. 2"9x xo 6 isolated from MoMuSV-349 virions. The biological properties of the replicating information in MoMuSV-I24 suggest that, consistent with the small size of RNA, it is defective, whereas MoMuSV-349 produces virions containing an intact MoMuLV genome, competent for replication.

Molecular Biological Characterization of a Highly Leukaemogenic Virus Isolated from the Mouse. III. Identity with Mouse Mammary Tumour Virus

“…Less than 0.1% VL30S R N A contaminated N I H 3T3 Mo-MuLV (Dekaban et al, 1980). (Ball, 1979;Dekaban et al, 1980) it was found that D M B A -L V contained nucleotide sequences which were only 4 3~ and 36~, respectively, related to the corresponding regions represented in the above two viral probes (data not shown). That the incomplete homology observed was not the result of D M B A -LV being composed of a deleted type C viral genome was confirmed in a second experiment in which the size of v R N A present in D M B A -L V was determined.…”

“…The established celt line TB was derived from a mixed culture of thymus and bone marrow ceils from CFW/D mice (Dekaban et al, 1980). Uninfected NIH 3T3 cells and Moloney murine leukaemia virus (Mo-MuLV) chronically infected JLS-V9 cells (MJD) were obtained from Dr K. Manly, and Dr V. Morris provided a GR mammary tumour cell line.…”

“…The extent of hybridization was assessed by measuring resistance to S~ nuclease as described by Leong et al (1972). All the numerical values given in the text (except those recorded in (Dekaban et al, 1980); the 28S and 18S, and 23S and 16S RNAs are ribosomal RNAs from TB cells and Escherichia coil respectively.…”

“…The MoMuLV was chosen because of the availability of extensively characterized representative c D N A probes Dekaban et al, 1980). Mo-MuLV grown on N I H 3T3 cells was used so that it would be free of any endogenous MuLV sequences characteristic of the C F W / D mouse (the strain of origin of DMBA-LV).…”

“…Furthermore, N I H 3T3 cell D N A does not contain a n y endogenous ecotropic MuLV proviral D N A and therefore the only ecotropic MuLV released by Mo-MuLV-infected N I H 3T3 cells was Mo-MuLV (Chattopadyhay et al, 1980;Chan et al, 1980). Less than 0.1% VL30S R N A contaminated N I H 3T3 Mo-MuLV (Dekaban et al, 1980). (Ball, 1979;Dekaban et al, 1980) it was found that D M B A -L V contained nucleotide sequences which were only 4 3~ and 36~, respectively, related to the corresponding regions represented in the above two viral probes (data not shown).…”