Study of the 78A1 isolate of Moloney murine sarcoma virus. II. Haematopoietic tropism and tumourigenicity.

A new isolate of Moloney murine sarcoma virus (Mo-MuSV), designated 78A1, has been molecularly cloned. The cloned genome, found to be larger than that of other known isolates of the same virus is close in size to that of the myeloproliferative sarcoma virus (MPSV), also a derivative of the original Mo-MuSV/Moloney murine leukaemia virus (Mo-MuLV) complex. Until now, MPSV was the only Mo-MuSV isolate known to be capable of inducing a myeloproliferative disease associated with a tumoural syndrome when injected intravenously into sensitive mice.

Study of the 78A1 isolate of Moloney murine sarcoma virus. I. Molecular cloning and characterization.

The 78A1 isolate of Moloney murine sarcoma virus (78A1 Mo-MuSV) was cloned from a genomic library obtained from virus producer rat cells, in the lambda vector L47. Among the recombinants hybridizing with a probe specific for the v-mos sequences, we recovered a recombinant which contained leukaemia virus (MuLV) sequences and was able to transform both mouse and rat cells in transfection experiments. The cloned provirus could be rescued by both Mo-MuLV ecotropic and amphotropic viruses in mouse cells, but only with the amphotropic helper virus in rat cells.

Characterization of viral RNA in cells transformed by various isolates of Moloney murine sarcoma virus.

Intracellular polyadenylated viral RNA from cells infected by five different isolates of Moloney murine sarcoma virus (Mo-MuSV) was analysed by gel transfer hybridization. Genomic sizes of 4.6 kilobases (kb) for the ml-MuSV isolate, 5.

Comparative immunochemical study of ribosomal proteins from various mammalian cells by two-dimensional immunoelectrophoresis.

Proteins isolated from ribosomal subunits of various mammalian cels were analysed comparatively by two different methods: a two-dimensional polyacrylamide gel electrophoresis system and a recently described two-dimensional immunoelectrophoresis technique. For this purpose, antisera were raised in rabbits against the total mixture of ribosomal proteins from murine cells. These sera were characterized by ring-test, double immunodiffusion and two-dimensional immunoelectrophoresis.

[Antigenicity of ribosomal proteins from a malignant mouse cell line. Preliminary results].

An original immunological two-dimensional technique with two different gels permits the protein analysis of 80 S cytoplasmic ribosomal murine particles and of their 60 S and 40 S subunits. The diagrams isolate and characterize a definite number of specific polypeptidic structures from each ribosomal particle.