抄録
A system of suppressor for the SD action in a natural population of D. melanogaster in Odate, Japan was analyzed. Most of the suppressors were located on the X chromosome. Two kinds of second chromosomes were found in the same population, one of which was a chromosome carrying insensitive element to the SD action and the other which inhibits the effect of suppressor. The effect of the suppressor was different for the SD which originated from different populations. The suppressor was located somewhere between the v and f loci on the X chromosome. The suppressor-X chromosomes were found to show slight but consistent meiotic drive, and in relation to this effect, a genetic mechanism regulating sex ratio in the population was discussed.
