Chromosomes of Oligotoma japonica (Embioptera)

Abstract

The chromosomes of Oligotoma japonica belonging to the Embioptera were preliminarily reported here. The number of chromosomes is 19 in the male (Fig. 2) and 20 in the female (Fig. 1). All the elements are characterized by the atelomitic fibre attachment. The sex-chromosome is represented by the largest V-shaped element, being unpaired in the male and paired in the female. Thus, the simple, male XO type of the sex-chromosome was clearly established in this interesting insect.