FGSC #5206

Mutant Type

Genus: N

reporting_genes: arg-5;acr-2;mtr;al-3 inl;rib-1;met-7

species: Neurospora crassa

allele: 27947 KH5(r) 15 RP100 83201t 51602(t) 4894

stock: M2043

glasgow:

mutagen:

Depositor: EK

Link Group: IIR;III;IVR;VR VR;VIR;VIIR

MT: a

Species No: 10

gene_back:

oppmt: 5205

trans:

ref1:

ref2:

site:

country:

ksudc_link: https://digital.lib.k-state.edu/item/neurospora-crassa/fgsc-5206

ksudc_link_html: https://digital.lib.k-state.edu/item/neurospora-crassa/fgsc-5206 ↗

Genes

Locus	Cultural Requirements	Link Group	Type
acr-2	III. Linked to thi-4 (0/286). Left of sc (3 to 6%) and spg (1 to 11%) (498, 816). acr-2 has been shown left of the centromere on published maps but without direct evidence. acr-2and trp-1 (on IIIR) cosegregated at the second division in 1 of 13 asci (H.B. Howe, Jr., personal communication), which would favor a right arm location. Resistant to acriflavine (494, 495); also resistant to 3-amino-1,2,4-triazole (seven alleles tested) (494). Resistance is probably dominant (heterokaryon tests) (498). Not resistant to malachite green. An excellent stable marker, fully fertile, with unambiguous scoring. Sizable inocula should be used to avoid false-negative tests. Use acriflavine at 50 µg /ml in minimal agar medium (816) (higher concentrations may be used) and aminotriazole at 0.5 mg/ml; both added before autoclaving.	III	B
al-3	VR. Between his-1 and inl (1%) (1119, PB). Carotenoids deficient (398). Reported to lack geranylgeranyl pyrophosphate synthetase activity and is blocked in soluble fraction, consistent with lesion between isopentenyl pyrophosphate and geranylgeranyl pyrophosphate (445), but can still produce farnesyl pyrophosphate (445) and steroids (398). (See Fig. 9.) This evidence contradicts in vivo labeling results that indicate a lesion between prephytoene pyrophosphate and phytoene (572). Strains carrying allele Y234M470 (al-3ros), formerly called rosy (49), become partially pigmented but are readily distinguished from the wild type. ylo-1 can be scored in combination with al-3ros (Y234M470) (PB). Strains carrying other alleles (e.g., RP100) (1119) are white with a trace of pink pigment. Biosynthetic pathway for carotenoids. It is thought that the same prenyl transferase catalyzes all the steps from dimethylallyl pyrophosphate to geranylgeranyl pyrophosphate (444; R.W. Harding, personal communication), and it has been proposed that a separate prenyl transferase converts dimethylallyl pyrophosphate to farnesyl pyrophosphate for sterol synthesis (445). The conversion of phytoene to the various carotenoid pigments involves a series of dehydrogenations, cyclizations, and other reactions. There must also be a cis/trans isomerization analogous to that found in tomato (842). The sequence of some of these steps is still uncertain; the pathway must branch, and there may be alternate routes to some of the products. See references 228, 443, 444, 842 and citations therein for proposed sequences. al-1 is probably blocked in phytoene dehydrogenase (398). It is not known whether this enzyme catalyzes the whole series of dehydrogenations. al-2 is reported blocked between geranylgeranyl pyrophosphate and phytoene (445) and between prephytoene pyrophosphate and phytoene (572). al-3 is alternately reported blocked between isopentenyl pyrophosphate and geranylgeranyl pyrophosphate (445) and between prephytoene pyrophosphate and phytoene (572), but it is not blocked in the production of farnesyl pyrophosphate or sterols (398, 445). ylo-1 is evidently blocked in a late step, probably either in the conversion of lycopene to 3,4-dehydrolycopene or in the conversion of either torulene or gamma-carotene to neurosporaxanthin (see citations in reference 398).	VR	B
arg-5	Uses ornithine, citrulline or arginine.	IIR	B
inl	VR. Between pho-3 (3 to 4%) and pab-1 (1 to 10%). Right of al-3 (362, 397, 1036). (482)Requires inositol (65). Lacks D-myoinositol-1-phosphatase (1142). Lack of glucocycloaldolase found by Pina and Tatum (826) is attributed by Williams (1142) to drastic repression of glucocycloaldolase by the concentration of inositol used for growth. Growth is colonial on low levels of inositol (367). Tends to extrude dark pigment into the medium when grown on suboptimal inositol. Composition of phospholipids and cell walls is abnormal on limiting inositol (367, 439, 440, 501). Inhibited by hexachlorocyclohexane (366, 457, 931). Conidia are subject to death by unbalanced growth on minimal medium (1028, 1033), a property exploited for mutant enrichment ("inositol-less death") (606, 647) because double mutants are at a selective advantage. Heat-sensitive allele 83201 is especially useful for mutant enrichment (832, 1043). Used in the first experiments reporting transformation of Neurospora by N. crassaDNA (677, 679) and reported to be efficient as a recipient in absence of inositol (1162). Used to study glucose (917) and sulfate (641) transport systems. Used extensively for studying induced reversion (392). Used for studying the mechanism of inositol-less death (647, 702), mutagenicity of ferrous ions, and regulation of mitochondrial membrane fluidity; for a review, see reference 702. Spontaneous reversion rates (386). Allele-specific partial suppressor (390). Allele 46802 is nonrevertable and inseparable from translocation 46802 (386, 808). Strains carrying heat-sensitive allele 83201 show slow semicolonial growth in liquid minimal medium at 25°C (641), but look normal on slants (D.D. Perkins, unpublished data). Strains carrying allele 89601 contain cross-reacting material (1183). Mutant gene exo-1 is present in the inl(89601) a stock FGSC 498 and may, therefore, be present in stocks of mutants derived by inositol-less death. (See references 194, 325, and 1027). Called inos.	VR	B
met-7	VIIR. Right of qa-2 (<1%), ars (<1%), and the centromere (one second-division ascus in several hundred). Left of met-9 (10[-4]) and wc-1 (1 to 4%) (146, 725; M.E. Case, personal communication). (718; M.K. Allen, cited in references 718 and 789) Uses cystathionine, homocysteine, or methionine (718; N. H. Horowitz, cited in reference 1180). Lacks cystathionine-gamma-synthase (547) (Fig. 17). This enzyme is also lacking in the mutant met-3 (547). See met-3 for regulation. Apparently contiguous with met-9by coconversion. Flanking markers are recombined in most met-7+ met-9+ recombinants (725). Functionally distinct from the mutant met-9, which has active cystathionine-gamma-synthase (547) but cannot use homocysteine. No mutants lacking both functions have been isolated. Allele NM251 is suppressible by supersuppressor RN33 (same as ssu-1?) (725). Allele K79 is inseparable from reciprocal translocation T(I;VII)K79 (808).	VIIR	B
mtr	IVR. Between pdx-1 (2%) and col-4 (1%) (101, 1017).Resistant to 4-methyltryptophan and p-fluorophenylalanine. pmn (= Pm-N, pm n), selected by resistance to p-fluorophenylalanine, has been shown to be alletic with mtr(R. Sadler and S. Ogilvie-Villa, personal communication; see also reference 248). Defective in transport of neutral aliphatic and aromatic amino acids via amino acid transport system I (as defined in reference 777) (248, 602, 1017, 1152). Causes an alteration in surface glycoproteins (1038). Used extensively for transport studies (247a, 1150 [review], 1152), also for studies of the mechanism of intralocus recombination (1021). Resistance is recessive in duplications from T(S1229) (PB). Recessive resistance used in a heterokaryon test system for mutation studies (1020). Suppressors obtained and used for selecting other resistance mutants (106, 107, 555, 1018). Allele 26 is a putative frameshift mutation reverted by ICR170 (106, 107). mtrascospores are slow to darken and mature; up to 50% of the young ascospores from heterozygous crosses are white (152, PB). With probable allele MN18, ascospore viability is improved by the addition of peptone to the crossing medium when the male parent is added (152). mtr has been scored on media containing 10 or 70 µg of filter-sterilized 4-methyltryptophan per ml or on 20 or 60 µg of p-fluorophenylalanine per ml (550, 1021, PB). Unlike 4-methyltryptophan, p-fluorophenylalanine is heat stable and can be added before autoclaving. Strains with mutations at the mtr locus may be obtained by selection for resistance to numerous agents or for defects in uptake ability. Thus, there is confusion in nomenclature. Genes originally designated neua, neur, neut, tru(628) may be mtr alleles. mtr was initially called mt (602).	IVR	B
rib-1	VIR. Between T(AR209) and pan-2 (3%). Right of ad-1 (3 to 6%), the centromere (1%), and glp-4 (4%) (486, 1012, 1102). (482) Requires riboflavin (681). Used to demonstrate role of flavin as a photoreceptor for carotenogenesis and for phase shifting and suppression of circadian conidiation (775). Allele 51602 is heat sensitive (34°C versus 25 C); allele C106 is not (380).	VIR	B