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Journal ArticleDOI

Arginaseless Neurospora: Genetics, Physiology, and Polyamine Synthesis

01 May 1970-Journal of Bacteriology (American Society for Microbiology)-Vol. 102, Iss: 2, pp 299-305
TL;DR: The results suggest that ornithine is the major source of the putrescine moiety of polyamines in Neurospora, and that putresCine is an essential growth factor for this organism.
Abstract: Four arginaseless mutants of Neurospora crassa have been isolated. All carry mutations which lie at a single locus, aga, on linkage group VIIR. A study of aga strains shows the arginase reaction to be the major, perhaps the only, route of arginine consumption in Neurospora other than protein synthesis. Ornithine-δ-transaminase, the second enzyme of the arginine catabolic pathway, is present and normally inducible by arginine in aga strains, and ornithine transcarbamylase, an enzyme of arginine synthesis, also has normal activity. Arginine inhibits the growth of aga strains. The inhibition can be reversed by spermidine, putrescine (1,4-diaminobutane), or ornithine. The results suggest that ornithine is the major source of the putrescine moiety of polyamines in Neurospora, and that putrescine is an essential growth factor for this organism. The inhibition of aga strains by arginine can be attributed to feedback inhibition of ornithine synthesis by arginine, combined with the complete lack of ornithine normally provided by the arginase reaction.
Citations
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Journal ArticleDOI

875 citations


Cites background from "Arginaseless Neurospora: Genetics, ..."

  • ...In the presence of arginine, aga strains grow very slowly unless ornithine or polyamines are added to the medium (41)....

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Journal ArticleDOI
TL;DR: Candida lipolytica synthetisiert das Antibioticum Tryptanthrin aus 1 Mol Tryptophan and 1 Mol Anthranilsaure as mentioned in this paper.
Abstract: Candida lipolytica synthetisiert das Antibioticum Tryptanthrin aus 1 Mol Tryptophan und 1 Mol Anthranilsaure. Bei Verfutterung von Tryptophan und substituierter Anthranilsaure, bzw. substituiertem Tryptophan und Anthranilsaure, konnten die zu erwartenden Tryptanthrinderivate isoliert und identifiziert werden. Die Enzyme der Tryptanthrinbiosynthese wiesen in bezug auf diese Substrate, mit Ausnahme von Bromtryptophan, keine Spezifitat auf. Parallel zu diesen Versuchen wurden durch chemische Synthese substituierte Tryptanthrine hergestellt. Die Dierivate wurden auf ihre antibiotische Wirksamkeit gepruft; als besonders wirksam erwiesen sich die halogenierten Verbindungen.

328 citations

Book ChapterDOI
TL;DR: Neurospora possesses several favorable features compared to the more conventional organisms that are used in cytogenetic research, and these, in part, compensate for the small size of its chromosomes.
Abstract: Publisher Summary This chapter concerns genetically significant aspects of Neurospora cytology, and the relation between genes and chromosomes, with special emphasis on chromosome rearrangements. In addition to reviewing the published literature, numerous results have been presented. Many of these are cytological, appearing under various headings. The chapter is also concerned with the morphology and identification of individual chromosomes. New genetic results concerning chromosome rearrangements and general characteristics of aberrations are given and a brief description of each known rearrangement has been provided. The chapter also deals briefly with other topics such as accessory, the genetic control of recombination, and the cytoplasmic genome. Neurospora possesses several favorable features compared to the more conventional organisms that are used in cytogenetic research, and these, in part, compensate for the small size of its chromosomes. All four products of individual meioses survive. Progeny can be obtained either as random meiotic products, as unordered tetrads, or as ordered tetrads whose linear spore arrangement reflects the events of meiosis. The spores show high viability and germination. The vegetative (somatic) part of the life cycle is haploid. Duplications are more readily identified as partial diploids against a haploid background than as partial triploids against a diploid background. Somatic variants can be obtained in pure culture. Any somatic cell can serve as a germ cell. For Aspergillus, only a few rearrangements have been recognized in other eukaryotic microorganisms, where usually they are more difficult to detect than in Neurospora, with its pigmented spores. Failure to recognize an existing rearrangement can lead to spurious conclusions regarding linkage, recombination, interference, preferential segregation, or the presence of synthetic lethal genes.

204 citations

References
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Journal Article
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.

289,852 citations

Journal ArticleDOI
TL;DR: The remarkable consistency of the distribution of the two lysine paths suggests that (a) they did not arise sporadically; (b) their distribution pattern was not disturbed by genetic exchange; and (c) there is a substantial evolutionary gap in organisms differing in path of l Lysine synthesis.
Abstract: With the aid of diagnostic radiocarbon tracers, lysine synthesis was studied in representatives of 21 orders of basidiomycetes, ascomycetes, and phycomycetes. The labeling pattern corresponding to the α-aminoadipic acid-lysine path was given by all basidiomycetes and ascomycetes and by those phycomycetes which produce non-flagellate or posteriorly uniflagellate spores. The pattern characteristic of the α,e-diaminopimelic acid-lysine path was shown by those phycomycetes which produce anteriorly uniflagellate or biflagellate spores. The remarkable consistency of the distribution of the two lysine paths suggests that (a) they did not arise sporadically; (b) their distribution pattern was not disturbed by genetic exchange; and (c) there is a substantial evolutionary gap in organisms differing in path of lysine synthesis. Neither lysine path is thought to have emerged in an organism possessing the other. The α,e-diaminopimelic acid path may be the more ancient. A common evolutionary precursor of organisms havi...

1,055 citations


"Arginaseless Neurospora: Genetics, ..." refers methods in this paper

  • ...a Vogel's (19) minimal medium (MIN), or Vogel's medium supplemented with 1 mM L-ornithine (ORN) or with 1 mM L-arginine (ARG)....

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  • ...N (19) supplemented with 100 to 200 ug of required amino acids....

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  • ...Vogel's medium N (19), containing ammonium as the primary N source, was used for physiological work....

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Journal Article

509 citations


"Arginaseless Neurospora: Genetics, ..." refers background in this paper

  • ...nidulans, has been described (16), and since the ornithine decarboxylase route of putrescine synthesis is widespread in nature (18)....

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  • ...Many organisms synthesize polyamines by way of ornithine decarboxylase (18), as shown in Fig....

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Journal ArticleDOI
TL;DR: Among artificially produced biochemical mutants of Neurospora, those which have lost the ability to synthesize methionine form the largest class, and some of the mutants require organically bound sulfur for growth, an indication that in these strains the block in methamphetamineionine synthesis comes at a later stage than sulfate reduction.

182 citations

Journal ArticleDOI

135 citations


"Arginaseless Neurospora: Genetics, ..." refers methods in this paper

  • ...Urea was determined by the Koritz-Cohen method (11), with unlimiting Cl- ion added to intensify and normalize color values (4)....

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