Non-Mendelian Inheritance of DNA-Induced Inositol Independence in
            <i>Neurospora</i>

Mishra, N. C.; Tatum, E. L.

doi:10.1073/pnas.70.12.3875

Cited by 110 publications

(37 citation statements)

References 14 publications

(6 reference statements)

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“…In such crosses (except for the cross no. 17 in Table 3) the inos+ and inos-characters were found to be transmitted in the expected (14). This suggests that the genetic information carried by exogenous RNA is readily transferred to the recipient DNA and thus would appear to implicate the enzyme reverse transcriptase.…”

Section: Resultsmentioning

confidence: 82%

See 1 more Smart Citation

Induction by RNA of inositol independence in Neurospora crassa.

Mishra¹,

Niu²,

Tatum³

1975

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

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Contributed by E. L. Tatum, December 9, 1974 -ABSTRACTThe effect of purified wild-type RNA (allo-RNA) on genetic reversion of inositol-requiring mutant 89601 of Neurospora crassa is described. The mutant (inos-) strain, on treatment with the wild-type RNA preparation, was found to revert to wild type (inos+) in significant numbers. RNA from the mutant (iso-RNA) and allo-RNA digested by RNase were ineffective in causing genetic reversion at the inositol locus. The allo-RNA-induced revertants were stable and showed a Mendelian transmission of the inos+ character.The role of DNA in genetic transformation is well known (1). Recently, such a role for RNA has been suggested by work with several biological systems. The acquisition of a drugresistant character by sensitive bacteria after treatment with purified RNA preparations from resistant strains has been described in pneumococcus (2), Bacillus subtilis (3), and Escherichia coli (4). The transfer of other genetic characters mediated by purified RNA preparations has also been reported (5, 6). In higher organisms the development of specifictissues in response to exogenous RNA during organ culture has been described (7,8). The possible role of RNA in transfer of genetic information is supported by the discovery of the enzyme, reverse transcriptase (RNA-dependent DNA polymerase) (9, 10), which can transcribe an RNA template into DNA. In this paper we describe the effect of exogenous RNA on genetic reversion at the inositol locus of Neurospora crassa. A preliminary account of this work has been presented (11).MATERIALS AND METHODSStrains. The Neurospora strains used were the wild-type (RL3-8A, RL21a) strains, the inositol-requiring morphological mutant strain (R2506-8-12, inos-rg-A) and the inositolrequiring strain 89601. These strains were obtained from the Rockefeller University collection and were maintained on minimal medium (12) supplemented with inositol.Chemicals. Deoxyribonuclease I (RNase-free) and ribonuclease were obtained from Worthington Biochemical Co. Other chemicals were reagent grade. Nitrocellulose membranes were obtained from the Millipore Co.Genetic Analysis. The genetic crosses were made on synthetic crossing medium (13). The genetic crosses and the heterokaryon analysis were performed by standard methods as described earlier (14). A large sample of ascospores was analyzed by methods described by Giles (15).Equal aliquots of ascospore suspension were added to liquified agar sorbose medium (16) with or without inositol supplement. After a heat treatment at 600 for 30 min, the medium containing the ascospores was distributed in sterile disposable petri plates (25 ml per plate). These plates were incubated at 250 for about 70 hr and then the growing colonies were counted.The inositol-independent revertant strains were examined for heterokaryosis (inos+/inos-) by plating equal aliquots of a suspension of conidia or mycelial fragments on sorbose-agar medium with and without inositol supplement. For a heterokaryotic culture, the number of colonies growi...

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Section: Resultsmentioning

confidence: 82%

“…The genetic crosses were made on synthetic crossing medium (13). The genetic crosses and the heterokaryon analysis were performed by standard methods as described earlier (14). A large sample of ascospores was analyzed by methods described by Giles (15).…”

mentioning

confidence: 99%

Induction by RNA of inositol independence in Neurospora crassa.

Mishra¹,

Niu²,

Tatum³

1975

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

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“…The frequency of transformation was significantly greater than the frequency of either spontaneous or induced reversion (Mishra and Tatum, 1973).…”

Section: Dna-andphage-induccd Transformationmentioning

confidence: 95%

Novel Techniques of Gene Transfer and Plant Improvement: An Appraisal of Transformation in Eukaryotes

Pandey

1978

New Phytologist

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SUMMARYCertain recent theoretical and technological advances make possible the development of new techniques for combining genes from diverse sources without normal sexual hybridization. These include: (1) DNA-and phage-induced transformation; (2) protoplast fusion and organelle transfer; (3) gametic transformation; and (4) graft hybridization. The essential feature of these novel techniques is 'transformation', broadly defined here as a phenomenon in which a part of the genetic information of one organism is combined with the entire genome of another. The present article reviews these topics briefly with reference to their potential value in plant improvement, and their contribution to a better understanding of induced transformation in flowering plants.A critical consideration of differences between prokaryotic and eukaryotic DNA leads to a better appreciation of possible natural constraints operating against gene transfer across this major evolutionary hne. Since transformation is essentially a natural mechanism in prokaryotes, and occurs in place of true sexuality and recombination, the occurrence of artificial transformation in eukaryotes may be considered to indicate an inherent capacity for recombination by transformation which has been superceded by the evolutionary development ofthe sexual mechanisms, meiosis and syngamy, but which may still be expressed if appropriate conditions can be generated. Fniture major developments may lie in discovering factors and techniques which would make eukaryotic organisms 'competent' as donors and recipients in transformation. It is suggested that the egg, zygote, and early embryonic cells may be better targets for transformation than differentiated somatic cells. The rapid successive divisions following fertilization of a eukaryotic egg cell presumably place heavy (.iemands on DNA metabolism, and this may allow exogenous fragments to compete more tuvourably for integration into new DNA strands.

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“…N. crassa was among the first fungi in which molecular transformation was accomplished, first by demonstration of supplement independence in inositol requiring mutants (Mishra & Tatum 1973), and soon by explicit complementation of auxotrophic mutations including the qa-2 mutant in an arom-9 background (Case et al 1979), and glutamate dehydrogenase ( am ) (Grant et al 1984; Kinsey & Rambosek 1984). Transformation protocols have varied over time, and reflecting the availability of key reagents, such as cell-wall degrading enzymes, and include protoplast transformation (Radford et al 1981; Buxton & Radford 1984), lithium acetate treatment of germinated conidia (Dhawale et al 1984), and most recently electroporation (Chakraborty et al 1991).…”

Section: Introductionmentioning

confidence: 99%

Diverse data supports the transition of filamentous fungal model organisms into the post-genomics era

McCluskey

Baker

2017

Mycology

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Filamentous fungi have been important as model organisms since the beginning of modern biological inquiry and have benefitted from open data since the earliest genetic maps were shared. From early origins in simple Mendelian genetics of mating types, parasexual genetics of colony colour, and the foundational demonstration of the segregation of a nutritional requirement, the contribution of research systems utilising filamentous fungi has spanned the biochemical genetics era, through the molecular genetics era, and now are at the very foundation of diverse omics approaches to research and development. Fungal model organisms have come from most major taxonomic groups although Ascomycete filamentous fungi have seen the most major sustained effort. In addition to the published material about filamentous fungi, shared molecular tools have found application in every area of fungal biology. Similarly, shared data has contributed to the success of model systems. The scale of data supporting research with filamentous fungi has grown by 10 to 12 orders of magnitude. From genetic to molecular maps, expression databases, and finally genome resources, the open and collaborative nature of the research communities has assured that the rising tide of data has lifted all of the research systems together.

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Non-Mendelian Inheritance of DNA-Induced Inositol Independence in Neurospora

Cited by 110 publications

References 14 publications

Induction by RNA of inositol independence in Neurospora crassa.

Induction by RNA of inositol independence in Neurospora crassa.

Novel Techniques of Gene Transfer and Plant Improvement: An Appraisal of Transformation in Eukaryotes

Diverse data supports the transition of filamentous fungal model organisms into the post-genomics era

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