Table II. Testing effect of the Δdim 2² allele on RIP.

Cross	Relevant genotypea	RIP (%)b	hph (%)c
N1879 × N1851	Δdim-2, am/am × Δdim-2	52
N1879 × N150	Δdim-2, am/am × (+)	48	42
N1880 × N1851	am/am × Δdim-2	56	58
N1880 × N150d	am/am × (+)	72
N1851 × N1879	Δdim-2 × Δdim-2, am/am	56
N150 × N1879	(+) × Δdim-2, am/am	24	38
N1851 × N1880	Δdim-2 × am/am	40	44
N150 × N1880d	(+) × am/am	64

^aΔdim-2 designates the Δdim-2² allele; am/am designates an am gene duplication resulting from an ectopic copy of am plus the native allele. When not listed, the alleles of dim-2 and am are wild type (+). The female strains are listed first.

^bRIP was calculated in all crosses for 50 random progeny as the ratio of Am^– progeny to one half of the number of total progeny.

^cProgeny were tested for independent segregation of the hph marker (expectation: 50%), which was inserted at dim-2 in building the dim-2 deletion allele.

^dProgeny from crosses with the strain N1880 were tested by Southern analysis for RFLP with BamH1 and EcoRI to verify the occurrence of RIP.