TABLE 1

Aberrant segregation and HIS4/LEU2 map distances for strains used in this study

StrainMethod of analysisTotal tetradsMutant allele6:22:65:33:50:4Aberrant 4:4Other PMSABS (%)PMS/ABS (%)HIS4/LEU2 map distancea (cM)
JDM1080Unselected59 his4u-lopc 3264010276924
bik1-lop 31630102471
fus1-BX 5200000120
ycl034W-SX 2800000170
JDM1086Unselected57 his4-IR9 1046000199021
his4u-lopc 2239000287519
bik1-lop 20311011b3290
fus1-BX 4400000140
ycl034W-SX 2500000120
JDM1086Selected-1c712 his4-IR9 22233741062d186624
JDM1086Selected-2e594 his4-IR9 22103832132f186924
JDM1086Strand transfer181 his4-IR9 831114001g207021
JDM1091Unselected158 his4-IR9 661213000236820
104 fus1-BX 7900000150
104 ycl034W-SX 61100000160
MD250Selected-LCTh302 his4-IR9 9121418002i186221
cha1::hphMX4 440000030
MD251Selected-LCTh1127 his4-IR9 46497086045j236321
cha1::hphMX4 1571100028

ABS, total aberrant segregations; PMS, postmeiotic segregations.

  • a Calculated using the Perkins (1949) equation. The HIS4/LEU2 map distance for MD251 was based on the analysis of 429 tetrads. b One aberrant 2:6.

  • c After scoring of the his4-IR9 marker, only those events exhibiting a 6:2, 2:6, 5:3, or 3:5 pattern of aberrant segregation (single events) at his4-IR9 were scored for the remainder of the markers.

  • d One aberrant 6:2 and one 7:1.

  • e This selection method was designed to identify tetrads that underwent a single recombination event initiated at the HIS4 DSB. First, his4-IR9 was scored for all tetrads. Next, all spores exhibiting a single PMS event at his4-IR9 were scored for bik1-lop. Only those tetrads in which the spore did not cosector for his4-IR9 and bik1-lop were completely scored for bik1-lop. Tetrads consistent with a single recombination event being initiated at HIS4 were scored for his4u-lopc and subsequently the flanking markers (fus1-BX and ycl034W-SX).

  • f One aberrant 2:6 and one 1:7.

  • g One 7:1.

  • h This method was used to identify events with long conversion tracts (LCT), events that involved conversion of all markers in the same direction (for example, 6:2 for fus1-BX and 2:6 for bik1-lop, his4u-lopc, his4-IR9, and ycl034W-SX). All tetrads were scored for his4-IR9 and cha1::hphMX4. Those events that involved conversion of both markers were subsequently scored for the flanking markers, bik1-lop, and his4u-lopc (if the markers continued to show conversion in the same direction).

  • i Two 7:1.

  • j One aberrant 2:6, three 7:1, and one 1:7.