TABLE 1

Progeny recovered from Embedded Image crossover

CrossoverRegular femaleRegular malerDNA crossover (%)Nondisjunctional (%)
y cv1931798 (7.66)14 (4.71)
y v f car9928489 (1.78)9 (0.66)
y cv v33923410 (5.57)5 (1.19)
y f car98367213 (2.58)16 (1.34)
y cv v f69836 (14.81)5 (3.90)
y car1641316 (6.83)0 (0.00)
y v91901 (2.15)2 (1.44)
y cv f car1481423 (3.90)3 (1.35)
y cv car70492 (5.41)1 (1.16)
y f22171 (8.33)1 (3.33)
  • A series of identical crosses were done of groups of females heterozygous for Rex and various marked X chromosomes that had different frequencies of an autosomal Su(Rex) in each group (L. G. Robbins, unpublished data). The crosses allowed detecting meiotic nondisjunction in the females and mitotic exchange between two rDNA arrays in their offspring.