Auxotrophic mutant involved in purine metabolism.
At 29oC flies exhibit guanosine auxotrophy.
A temperature-sensitive guanosine auxotroph. Hemizygous viability on guanosine-free medium reduced at 25oC; virtually lethal at 29oC although completely supplementable at that temperature. Normal allele thought to function in the conversion of inosinic acid to guanilic acid.