FGSC #1888

Mutant Type

Genus: N

reporting_genes: al-1;arg-5;trp-1;ylo-1

species: Neurospora crassa

allele: 34508;27947;10575;Y30539y

stock: 9174

glasgow:

mutagen:

Depositor: DDP

Link Group: IR;IIC;IIIR;VIL

MT: a

Species No: 10

gene_back:

oppmt: 2124

trans:

ref1:

ref2:

site:

country:

ksudc_link: https://digital.lib.k-state.edu/item/neurospora-crassa/fgsc-1888

ksudc_link_html: https://digital.lib.k-state.edu/item/neurospora-crassa/fgsc-1888 ↗

Genes

Locus	Cultural Requirements	Link Group	Type
al-1	IR. Right of hom (<1%), arg-6 (<1 to 4%), T(T54M94), and al-2. Left of lys-3 (9%). (797, 808; D.D. Perkins, unpublished data). (482) Carotenoids abnormal. Strains carrying the various alleles differ widely in phenotype, ranging from white (e.g., 4637) and "aurescent" (pigment in peripheral conidia and conidiophores, 34508) to yellow mycelia and conidia (e.g., ALS4 and RES-25). See, for example, reference 1042. Strains carrying alleles ALS-14, RES-6, 34508, and RES-25 contain large amounts of phytoene (99 to 100% of the total neutral carotenoids), suggesting a lesion that affects phytoene dehydrogenase (398, 1039) (see Fig. 9). Strains carrying allele RWT-ylo accumulate zeta carotene and smaller amounts of neurosporene, suggesting a leaky block of the step between these intermediates (1071). It is not known whether phytoene dehydrogenase catalyzes the whole series of dehydrogenations or whether leakiness of this enzyme accounts for the different mutant phenotypes. For complementation tests, see references 500, 1039, and 1041. Fine-structure mapping (500, 1042). Translocation T(4637), inseparable from al-1, was the first albino mutation and one of the first chromosome rearrangements in Neurospora to be identified and studied (656). Allele 34508 called aur: aurescent.	IR	B
arg-5	Uses ornithine, citrulline or arginine.	IIR	B
ylo-1	VIL. Between cys-1 (8%) and ad-1 (6%). Probably right of Bml (2%) (1012, PB). (381). Yellow carotenoids (381). Affects synthesis of neurosporaxanthin (4'-apo-beta'-caroten-4'-oic acid); citations in reference 398. Lesion probably involves the conversion of lycopene to 3,4-dehydrolycopene or the conversion of either torulene or gamma-carotene to neurosporaxanthin (398 and references therein) (Fig. 9). Resembles the orange wild type in young cultures, but color differences become clear with age. Expressed in both conidia and mycelia. Undefined modifiers affect intensity. Fails to complement with many of the al-1 and al-2 albino strains (R.E. Subden, personal communication).	VIL	B
trp-1	IIIR. Between ad-2 (1 to 7%) and ro-2 (2 to 12%) (11, 219, 812). Linked to fpr-3 (< 1%) (550). (504). Uses tryptophan or indole (1060); strains carrying some alleles can also use anthranilate; others cannot (4). trp-1+ and trp-2+ gene products together form an enzyme aggregate with three activities: anthranilate synthetase, phosphoribosyl-anthranilate isomerase, and indoleglycerol-phosphate synthetase (181, 260) (Fig. 11). trp-1 codes for the beta subunit of the aggregate (546); it specifies phosphoribosyl-anthranilate isomerase, indoleglycerol-phosphate synthetase, and collaboratively the glutamine amino transferase activity of anthranilate synthetase (29, 181, 502). Strains carrying different alleles differ in lacking one or more of the three activities, e.g., trp-1 (allele 15) lacks all three activities; trp-1 (20) lacks only phosphoribosyl- anthranilate isomerase, trp-1C (1) lacks only anthranilate synthetase, trp-1 (25) lacks both phosphoribosyl-anthranilate isomerase and indoleglycerol-phosphate synthetase, etc. (259). (To avoid confusion, note that in reference 259 and related papers, the same "allele number" may be used for a trp-2 mutation, a trp-1 mutation [non-anthranilate-utilizing], and a trp-1Cmutation [anthranilate utilizing]; mutations of the last class are listed by FGSC as trp-1 with the allele number prefixed by C.) Strains carrying different alleles differ in their ability to form aggregates (181, 259). Association between trp-1 and trp-2products is essential for glutamine-dependent anthranilate synthetase activity but not the other two activities (181). The trp-1 gene has been cloned (545, 925), sequenced (925), and reintroduced into Neurospora by transformation (925). It is only partially expressed in E. coli. Fine-structure maps (10, 259). Complementation maps (10, 163). Reviewed as example of gene fusion (218). Nonsense allele used to demonstrate restoration of normal enzyme aggregate by supersuppressors (183). Alleles that accumulate anthranilate are scorable by blue fluorescence under long-wave UV after 2 to 5 days of growth on minimal medium plus indole (10 µg /ml), 34°C (814, 816). Aging cultures may produce brown pigment; blue fluorescence disappears as pigment forms.	IIIR	B