met-1 | IVR. Right of oxD (3%) and the T(S1229) left breakpoint. Left of col-4 (4%) (55, 158, 718, 768, 808). Uses methionine but not homocysteine (469) (Fig. 17). Lacks methylene tetrahydrofolate reductase and, thus, lacks the coenzyme needed for transmethylating homocysteine (124, 963, 964). A report that the mutant met-1 also lacks cystathionine-gamma-synthase (547) proved incorrect; the error resulted because methyl tetrahydrofolate is an essential activator of cystathionine-gamma-synthase (965). Methylene tetrahydrofolate reductase is feedback-inhibited by S-adenosylmethionine (124). Used in heteroallelic duplications from T(S1229) to assay mitotic recombination (56). | IVR | B |