Genetic Recombination among Temperature-sensitive Mutants of Rous Sarcoma Virus

Wyke, John A.; Bell, J.G.; Beamand, Jennifer A.

doi:10.1101/sqb.1974.039.01.104

Cited by 66 publications

(43 citation statements)

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“…DISCUSSION The complete absence of a number of typical RAV-1 and Pr RSV-B oligonucleotides from all progeny clones selected as recombinants argues against contamination by parental virus, so that there is no reason to ascribe the host range properties to phenotypic mixing. The large proportion of double crossovers found in our small sample may be the consequence of extensive recombination (11,12), but it should also be considered that proviral DNA passes through a circular state (13,14) and that recombination between DNA circles can intrinsically give rise to a high yield of double recombinants (15,16). The fact that in three out of five recombinational events at the right-hand side of the genome crossingover took place at apparently the same position may indicate a "hot-spot" for recombination.…”

Section: Resultsmentioning

confidence: 87%

Mapping of biological functions on RNA of avian tumor viruses: location of regions required for transformation and determination of host range.

Joho¹,

Billeter²,

Weissmann³

1975

Proc. Natl. Acad. Sci. U.S.A.

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A map of the large T1 oligonucleotides of the RNA of Prague Rous sarcoma virus, strain B (Pr RSV-B) has recently been established (Coffin and Billeter, submitted for publication). Since the RNA of Rous associated virus, type 1 (RAVy-) lacks many of the large T, oligonucleotides of Pr RSV-B and contains others not present in the latter, the RNA of recombinants between RAV-1 and Pr RSV-B could be analyzed with regard to the origin of its sequences. Recombinants were selected for transforming capacity (characteristic for Pr RSV-B) and ability to grow on C/B chicken fibroblasts (characteristic for RAV-i). Four out of five recombinants examined had undergone at least two crossovers. The set of Pr RSV-B-specific oligonucleotides present in all recombinants defined an RNA region near the poly(A) segment; this must contain genetic information required for transformation (the onc function). All recombinants lost a set of contiguous Pr RSV-B-specific oligonucleotides and concomitantly acquired a set of RAV-1-specific oligonucleotides. These define a region in the middle section of the oligonucleotide map, all or some of which must be required for determining growth capacity on C/B cells (the env function).Work in several laboratories has shown that oncornavirus RNA can be characterized by the large oligonucleotides resulting from its digestion with T1 RNase and that different strains of avian oncornaviruses yield different and characteristic patterns of large T1 oligonucleotides (1-5). This analytical approach has been used to show that Rous sarcoma virus (RSV) contains two to three identical subunits with a molecular weight of about 3.4 X 106 (3-8), and to demonstrate that the RNAs of recombinants from a cross between two different strains of avian tumor viruses yield T1 oligonucleotides characteristic for each of the parents (3).A map of the large T1 oligonucleotides of the RNA of Prague Rous sarcoma virus, subgroup B (Pr RSV-B) has recently been established (Coffin and Billeter, submitted for publication). In this paper we describe a new approach for mapping biological functions on an oncornavirus genome. Crosses are performed between two virus strains that differ in one or more characteristic biological properties as well as in a substantial proportion of their large T1 oligonucleotides. The biological properties of cloned progeny are then correlated with the presence or absence of typical T1 oligonucleotides. If the oligonucleotide map of at least one of the viruses is known, it is possible to locate the selected functions on the genome. Using this approach we have mapped transforming capacity at the 3'-terminal region of Pr RSV-B RNA and host range in the middle section of the genome. RESULTSPreparation and characterization of recombinants between Pr RSV-B and RAV-1 Chicken fibroblast cells (C/O, chf-) (9, 10) were coinfected with Pr RSV-B (subgroup B, a transforming virus) and RAV-1 (Rous-associated virus, type 1, subgroup A, a nontransforming virus), and five presumptive recombinants (transformation positi...

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Section: Resultsmentioning

confidence: 87%

Mapping of biological functions on RNA of avian tumor viruses: location of regions required for transformation and determination of host range.

Joho¹,

Billeter²,

Weissmann³

1975

Proc. Natl. Acad. Sci. U.S.A.

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“…Retroviruses package two complete viral genomic RNAs in each virion, and this specific configuration facilitates recombination by template swapping during reverse transcription. Recombination between retrovirus genomes has been demonstrated during mixed infection with genetically marked avian tumor viruses (4,19,47,53,54), murine leukemia viruses (15,52), and human retroviruses (9). Also, exogenous viruses can recombine with endogenous retrovirus sequences (13,38,49).…”

Section: Discussionmentioning

confidence: 99%

Characterizing and Mapping Porcine Endogenous Retroviruses in Westran Pigs

Lee

Webb

Allen

et al. 2002

J Virol

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“…Retroviral recombination was initially identified in avian retroviruses (20,51) and appears to be a common feature of retroviral replication in general (7,54,56). To examine the rates and mechanism of retroviral recombination, a system based upon spleen necrosis virus (SNV), isolated from birds, was established (2,16,17).…”

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confidence: 99%

Human Immunodeficiency Virus Type 1 Recombination: Rate, Fidelity, and Putative Hot Spots

Zhuang

Jetzt

Sun

et al. 2002

J Virol

225

204

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Previously, we reported that human immunodeficiency virus type 1 (HIV-1) recombines approximately two to three times per genome per replication cycle, an extremely high rate of recombination given the relatively small genome size of HIV-1. However, a recombination hot spot involving sequence of nonretroviral origin was identified in the vector system utilized, raising the possibility that this hot spot skewed the rate of recombination, and the rate of recombination observed was an overestimation. To address this issue, an HIV-1-derived vector system was used to examine the rate of recombination between autologous HIV-1 sequences after restricting replication to a single cycle in the absence of this hot spot. Viral DNA and RNA were analyzed by a combination of the heteroduplex tracking assay, restriction enzyme analysis, DNA sequencing, and reverse transcription-PCR. The results indicate that HIV-1 undergoes recombination at a minimum rate of 2.8 crossovers per genome per cycle. Again, this is a very high rate given the small size of the HIV-1 genome. The results also suggested that there might be local hot spots of recombination at different locations throughout the genome since 13 of the 33 strand transfers identified by DNA sequencing shared the same site of recombination with one or two other clones. Furthermore, identification of crossover segments also allowed examination of mutations at the point of recombination, since it has been predicted from some studies of cell-free systems that mutations may occur with a frequency of 30 to 50% at crossover junctions. However, DNA sequence analysis of crossover junctions indicated that homologous recombination during viral replication was not particularly mutagenic, indicating that there are other factors or conditions not yet reproduced in cell-free systems which contribute to fidelity during retroviral recombination.

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Genetic Recombination among Temperature-sensitive Mutants of Rous Sarcoma Virus

Cited by 66 publications

References 0 publications

Mapping of biological functions on RNA of avian tumor viruses: location of regions required for transformation and determination of host range.

Mapping of biological functions on RNA of avian tumor viruses: location of regions required for transformation and determination of host range.

Characterizing and Mapping Porcine Endogenous Retroviruses in Westran Pigs

Human Immunodeficiency Virus Type 1 Recombination: Rate, Fidelity, and Putative Hot Spots

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