FGSC #3167

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Reporting Genes: T(I->V)AR190 met-6 al-1

Species: crassa

Allele: 35809 ALS4

Alternate Strain Number: isolate R19a

Depositor: RLM

Linkage Group: I;V

Mating Type: a

Species Number: 10

ref1: Perkins & Barry Advances in Genetics 1977, https://doi.org/10.1016/s0065-2660(08)60246-1

Deposit Sheet ↗

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 (797, 808; D.D. Perkins, unpublished data).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
met-6	IR. Right of T(NM103), T(ALS182), and thi-1 (7 to 14%) (808, 1091, PB). Left of ad-9 (2 to 16%) (466, 723, 789). Adjoining or allelic with mac (722, 724). (125) Requires methionine; does not use precursors (718; N. H. Horowitz, cited in reference 1180). Strain(s) carrying allele 35809 lacks polyglutamate forms of folate and, thus, apparently lacks the coenzyme needed for transmethylating homocysteine (208, 886, 963, 964) (Fig. 17). An incorrect report that the mutant met-6 also lacks cystathionine-gamma-synthase (547) proved to be due to the methyl tetrahydrofolate being removed during preparation of extracts; methyl tetrahydrofolate is an activator of cystathionine-gamma-synthase (965). The relationships between met-6 (35809) and its probable alleles met (S2706) and mac (65108) are not clear. met (S2706) and mac both complement met-6 (35809), but do not complement each other, indicating that at least met (S2706) and mac are alleles. In a high-resolution recombination study with flanking markers, met-6 (35809) and met (S2706) behaved like alleles, but mac behaved atypically, although almost equally closely linked (724). The mac mutant is reported to differ from the others in causing an accessory requirement for adenine and possibly cystine (290), whereas met-6 (35809) and met (S2706) strains are stimulated by adenine only in a CO2-enriched atmosphere (G. Roberts, cited in reference 724). mac and met-6(35809) strains evidently lack different folylpolyglutamate synthetase activities (208, 886). Used to study polarity in intralocus recombination (722, 724). Polarity with respect to flanking markers is not reversed when the met-6 region is inverted relative to the centromere (722).	IR	B
T(I->V)AR190	Translocation		B