TABLE 4

Frequencies of 3:1 segregation

Predicted % of
undiagnosed
false tetrads
% 3:1 segregationc
StrainaTotal
tetradsb
CAN1URA3HOM3TRP2
Chromosome V
TID114090.80.8/0.70.3/0.20.6/0.51.4/1.3
tid1-pTID112220.41.1/1.00.6/0.50.6/0.61.6/1.5
TID1 combined26310.60.9/0.80.4/0.30.6/0.51.5/1.4
tid111182.92.4/1.8*1.4/0.81.1/0.83.2/2.8*
Predicted % of
undiagnosed
false tetrads
% 3:1 segregationc
StrainaTotal
tetradsb
MATLEU2URA3
Chromosome III
TID112503.11.3/0.2d6.4/6.21.8/1.5
tid113201.71.8/1.2*6.4/6.21.5/1.3
DMC1-YEpRAD5412750.40.7/0.54.5/4.50.9/0.8
dmc1Δ-YEpRAD5413620.60.4/0.27.6/7.5*0.7/0.6
  • Postmeiotic segregation was not detected in this experiment. Numbers presented are sums of the frequencies of 3+:1- and 1+:3- tetrads.

  • a See footnotes a and b of Table 2 for names of strains used and marker locations.

  • b Number of tetrads dissected minus the number of tetrads that were diagnostically false. The predicted percentage of undiagnosed false tetrads was calculated as [(Nf2 + NN3) - (Nm3:1 + NN4:0)]/Total × 100 (see appendix).

  • c Percentages of observed frequencies/percentages corrected for the contribution of false tetrads (see appendix) are shown. *, the corrected value of 3:1 frequency for a mutant is significantly different from that of the wild-type control on the basis of Fisher’s exact test.

  • d The large correction factor required makes this value less reliable than other estimates (see text).