Title: STUDIES WITH PURPLE ADENINE MUTANTS IN NEUROSPORA CRASSA. V. EVIDENCE FOR ALLELIC COMPLEMENTATION AMONG ad-3B MUTANTS
Abstract: Heterokaryon tests of all possible combinations of 161 ad-3B mutants of independent origin were made in duplicate in test tubes containing liquid minimal medium. Only 112 (0.4 percent) of the 25,760 pairwise combinations involving different mutants were positive. All combinations showing positive tests involved one of four leaky mutants and 14 nonleaky mutants. Growth tube studies on the heterokaryons revealed a wide range of growth rates from wild type to oniy slightly faster than the rate of leaky mutant itself. These tests show that the complementation map of the ad-3B cistron consists of at least two complementation subgroups or complons. (auth)