title: Expression of mink cell focus-forming murine leukemia virus-related transcripts in AKR mice.
abstract: We used a synthetic 16-base-pair mink cell focus-forming (MCF) env-specific oligomer as radiolabeled probe to study MCF murine leukemia virus (MuLV)-related transcripts in brain, kidney, liver, spleen, and thymus tissues of AKR mice ranging from 5 weeks to 6 months (mo) of age. Tissue-specific expression of poly (A) + RNAs was seen: 6.0-kilobase (kb) transcripts were detected in the liver and kidney; 7.2- and 1.8-kb RNA species were present in the thymus. In addition, all the tissues tested contained 3.0-kb messages. The transcription of these MCF-related mRNAs was independent of the presence of ecotropic and xenotropic MuLVs. In general, expression of the MCF env-related transcripts appeared to peak at 2 mo of age; these messages were barely detectable in brain, kidney, liver, and spleen tissues after 2 mo and in thymus tissue after 4 mo of age. All of the subgenomic MCF env-related mRNAs (6.0, 7.2, 1.8, and 3.0 kb) appeared to contain the 190-base-pair cellular DNA insert, characteristic of the long terminal repeats associated with endogenous MCF env-related proviruses (A. S. Khan and M. A. Martin, Proc. Natl. Acad. Sci. USA 80:2699-2703, 1983). No genomic-size (8.4-kb) transcripts corresponding to endogenous MCF-related proviruses were detected. An 8.4-kb MCF env-related mRNA was first seen at 3 mo of age, exclusively in thymus tissue. This species most likely represents the first appearance of a recombinant MCF-related MuLV genome. The transcripts which were detected in thymus tissue might be involved in the generation of leukemogenic MCF viruses.
mesh_terms: D000367:Age Factors; D000818:Animals; D005786:Gene Expression Regulation; D009052:Leukemia Virus, Murine / Q000235:genetics*; D051379:Mice; D008806:Mice, Inbred AKR / Q000235:genetics / Q000382:microbiology*; D008908:Mink Cell Focus-Inducing Viruses / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D014018:Tissue Distribution; D014158:Transcription, Genetic; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D014759:Viral Envelope Proteins