FGSC #3820

Mutant Type

Genus: N

reporting_genes: un-3 ad-3A nic-2 al-2;tol hetcDE

species: Neurospora crassa

allele: 55701(t) 2-17-814 43002 Y112M38 N83

stock: I-34-8

glasgow:

mutagen:

Depositor: AJG

Link Group: IL IR IR IR;IVR

MT: A

Species No: 10

gene_back:

oppmt: 0

trans:

ref1: Griffths & DeLange 1977 Mutation Res 46:345-354, https://doi.org/10.1016/0165-1161(77)90011-5

ref2:

site:

country:

ksudc_link: https://digital.lib.k-state.edu/item/neurospora-crassa/fgsc-3820

ksudc_link_html: https://digital.lib.k-state.edu/item/neurospora-crassa/fgsc-3820 ↗

Genes

Locus	Cultural Requirements	Link Group	Type
al-2	IR. Right of os-5 (<1%) and T(STL76). Left of arg-6(1%) and al-1 (797, 802, 808, 816, 818). Included in duplications from Tp(T54M94), confirming location left of arg-6(808). (482) Carotenoids absent or abnormal, but steroids produced (398). Blocked in microsomal fraction and defective in phytoene synthetase (445), a particulate enzyme (445 and references cited therein) (Fig. 9). Tracer experiments indicate a lesion between prephytoene pyrophosphate and phytoene (572). Alleles include those resulting in white and pale rose-white, e.g., 15300 and Y254MI65 (1042), and purple, e.g., MN58a (154). For complementation, see references 500 and 1041. Fine-structure mapping (500, 1042) needs reevaluation because of new information on the location of the arg-6 marker (797).	IR	B
hetCDE			B
nic-2	IR. Between ad-3B (4%) and ace-7 (4 to 7%) (271, 578). (482) Grows on nicotinic acid, nicotinamide, or high concentrations of quinolinic acid (97, 1168). Cannot use kynurenine, hydroxykynurenine, or hydroxyanthranilic acid (96, 1168). Accumulates 3-hydroxyanthranilic acid (96) (Fig. 18). Aging cultures accumulate red-brown pigment in the medium. Used to study intralocus recombination (908). Translocations T(4540) and T(S1325)are inseparable from nic-2 (808, 908, 911).	IR	B
tol	IVR. Linked to trp-4 (~1%), probably to the left (755). Suppresses the vegetative (heterokaryon) incompatibility associated with mating type alleles A and a, but does not affect sexual compatibility. (tol;A+ tol;a) heterokaryons are fully compatible and stable if other het loci are homokaryotic, and A/a duplications grow normally when tol is present (755). Recessive (252); see reference 746, however, for a stable mixed-mating type heterokaryon that is (tol a + tol+ slime A). tol does not suppress the vegetative incompatibility of differing alleles at het-c or het-e(755, 803). Mutation or deletion of tol+ restores normal growth rate to slow-growing, unstable, mixed-mating-type (tol a + tol+ A) heterokaryons (252). tol is present in some isolates from nature and has arisen at least twice by mutation in laboratory stocks (755, PB; O.C. Yoder, personal communication). Double-mutant tol trp-4 stocks are convenient because the closely linked trp-4 tags the tol allele, which otherwise requires progeny tests for scoring. Used to maintain stable A + a heterokaryons, allowing the desired component to be used as the parent in a cross (746). Homozygous tolmay partially restore fertility to the mutant fmf-1 (531).	IVR	B
un-3	IL. Right of In(NM176); hence, right of ser-3 (1%) (1093). Left of mt(0.04 to 0.1%) (488, 758). Closest bracketing marker left of mt (482). Unknown function. Heat sensitive (484). Growth drops off sharply between 28.5°C and 30°C (R.L. Metzenberg, personal communication). Multiply transport deficient at permissive temperatures with increased fragility of protoplasts (543); reduced rate of uptake of citrulline (1075) and aspartate (543, 1149). Resistant to ethionine and to p-fluorophenylalanine at 25°C (542, 543). Used to tag mating type (487) and as a flanker in an attempt to resolve the mating type region by recombination (758). Strains with probable un-3alleles are selected as citrulline-resistant mutants of pyr-3 arg-12s; most mutants selected in this way show complementation between alleles (1075). A possible functional relation to mating type is discussed in reference 543, Growth at 25°C aided by 0.3 mg of sodium acetate per ml. May be scored by slow growth at 25°C if acetate is not added to minimal medium (487). Formerly called un(55701).	IL	B
ad-3A	IR. Between his-3 (1 to 2%) and ad-3B (0.1 to 0.7%) (271). Right of ure-4 (78). (482) Requires adenine or hypoxanthine (682). Blocked in interconversion of CAIR plus aspartate to SAICAR (348) (Fig. 8). Produces purple pigment, permitting direct visual selection (276, 682); see the ad-3B entry. Reduced interallelic fertility (407). No interallelic complementation (267; F.J. de Serres, personal communication). ad-3A and ad-3B are two genetically and functionally distinct loci separated by a short but functionally complex region of unknown but essential function (271, 407). They have been used intensively for quantitative genetic and molecular studies of mutation (for a review, see reference 35). Either forward mutation (e.g., reference 277) or reverse mutation (e.g., reference 772) can be measured precisely; the former is detected visually by purple pigment. Purple pigment has also been used to assess the effect of histidine and tryptophan on purine nucleotide synthesis (786). Alleles N23 and N24 have been used as mutagen testers. N23 reverts with agents that cause base pair substitutions; N24 reverts with agents that cause frameshifts (772). SK(ad-3A) is at or near ad-3A and may be a cryptic ad-3A allele. Does not require adenine. In SK(ad-3A)x ad-3Acrosses, the ad-3A progeny die; possibly SK(ad-3A) mutants fail to make enough adenine to support their growth (251). Translocations Y155M64 ad-3A (272; PB) and Y112M15 ad-3A(413) each have one breakpoint that is inseparable from ad-3A. Called complementation group A (264). "A" in the locus symbol does not refer to mating type.	IR	B