FGSC #2204

Reporting Genes: uc-1;uc-3;pyr-4

Species: crassa

Allele: RW57;RW203;33601

Mutagen: UV

Depositor: LGW

Linkage Group: II;--;IIL

Mating Type: a

Species Number: 10

Genetic Background: M

ref1: Williams and Mitchell 1969. J. Bact. 100:383-389, https://doi.org/10.1128/jb.100.1.383-389.1969

Genes

Locus	Cultural Requirements	Link Group	Type
pyr-4	IIL. Right of het-c (1%), T(P2869), and cys-3 (18 to 21%). Left of ro-3 (1 to 2%) (721, 816, PB). (812). Requires uracil or other pyrimidine. Lacks orotidine 5'-monophosphate decarboxylase (133, 134, 841) (Fig. 20). Fertile crosses homozygous for pyr-4 can be made by using very high levels of uridine (15 to 20 mg/ml) (O.M. Mylyk, personal communication).	IIL	B
uc-3	Unmapped. Thymidine salvage pathway defect (Fig. 23). Unable to use thymidine, thymine, or hydroxy-methylcytosine, but can use deoxyuridine, 5-formyluracil, uracil, or uridine to support growth of pyr-4 when uc-1 is also present. Excretes thymine into the medium when grown in the presence of thymidine (1141). Lacks thymine 7-hydroxylase, which catalyzes the reactions thymine -> 5-hydroxymethyluracil -> 5-formyluracil -> uracil-5-carboxylic acid; apparently, there is an alternate enzyme for 5-formyluracil -> uracil-5-carboxylic acid, which explains the growth on 5-formyluracil (616, 977).		B
uc-1	II. Linked to pyr-4 (31%) (1139, 1141). Altered thymidine salvage pathway (Fig. 23). Able to use thymidine, thymine, 5-hydroxy-methyluracil, or 5-formyluracil as the sole pyrimidine source in germinating conidia of pyr-4 mutants, which are blocked in pyrimidine biosynthesis. (In uc-1+ background, pyr-4 can use these compounds only if a primer of uridine or cytidine is supplied [1141]). Causes elevated activities of enzymes which oxidatively demethylate thymine (420).	II	B

Neurospora Crassa Wikipedia