TABLE 1.
Crossover tetrad types from the cross A m B × a + b
| No conversion:a | Conversion at ma
|
||
|---|---|---|---|
| Normal 4:4 | Aberrant 4:4 | 5:3 | 6:2 |
| A m/m B | A m/m B | A m/m B | A m/m B |
| A m/m b | A m/+ b | A m/m b | A m/m b |
| a +/+ B | a +/m B | a m/+ B | a m/m B |
| a +/+ b | a +/+ b | a +/+ b | a +/+ b |
Tetrads are monitored for crossing over between markers A and B, closely bracketing site m.
a
The Watson–Crick duplex nature of the haploid products of meiosis is indicated only for site m. In the 5:3 and 6:2 tetrads, conversion has been arbitrarily indicated in favor of the mutant marker. In the text, 5:3 and 6:2 indicate combined frequencies of conversion without regard to whether the conversion favored m or favored +.