TABLE 4

Analysis of crossover interference in wild-type (EAY1108/EAY1112) and mms4Δ, mlh1Δ, and msh5Δ derivatives

Coefficients of coincidence (COC observed/COC expected)
NPD ratios (NPD observed/NPD expected)URA3-LEU2-LYS2LEU2-LYS2-ADE2
Relevant genotypeADE2-HIS3URA3-LYS2LYS2-HIS3TetradsSporesTetradsSpores
Wild type0.097**
 (16/165.6)<0.253**
 (45/>178)<0.258**
 (46/>178)0.717**
 (177/246.9)0.799**
 (218/272.9)0.458**
 (65/141.9)0.550**
 (88/160.1)
mms4Δ   0**
 (0/15.5)0.321**
 (6/18.7)0.107**
 (2/18.7)0.789
 (20/25.3)0.781**
 (94/120.3)0.555
 (8/14.4)0.633**
 (43/67.9)
mlh1Δ0.415*
 (5/12.1)0.197**
 (4/20.4)0.540*
 (11/20.4)0.573**
 (19/33.1)0.649**
 (33/50.8)0.646
 (14/21.7)0.628*
 (22/35.0)
msh5Δ0.880
 (9/10.2)0.808
 (7/8.7)0.965
 (13/13.5)1.184
 (20/16.9)1.658a
 (59/35.6)0.747
 (10/13.4)0.990
 (29/29.3)
mlh1Δ msh5Δ0.611
 (9/14.7)1.562a
 (23/14.7)0.658
 (15/22.8)1.092
 (37/33.9)1.052
 (78.5/74.6)0.651
 (15/23.0)1.352a
 (68/50.3)
  • a Although double crossovers deviated significantly from the expected number in this interval, the COC (NPD ratio) is >1, indicating negative interference.

  • Interference was calculated from data presented in Tables 1 and 2. Asterisks indicate that the observed number of NPDs or COCs deviated significantly from the expected number based on a two-tail binomial test (Categorical Statistics Package, http://engels.genetics.wisc.edu), suggesting that interference is present in the interval (*P < 0.05; **P < 0.01).