SPONTANEOUS MALE CROSSING-OVER OF FREQUENT OCCURRENCE IN DROSOPHILA ANANASSAE FROM SOUTHEAST ASIAN POPULATIONS

Drosophila ananassae from six geographical localities in Southeast Asia were examined in the recombination frequencies in the male. The investigation reveals that male crossing-over may be very common. At least in the second chromosome from these populations, almost all males can be expected to carry some genetic elements to cause male recombination, although in general the recombination value in the male was not always so high as that in the female.The equality of complementary crossover classes in each family was observed suggesting the meiotic origin of the event.Positive correlation between recombination and k values was obtained.