Synchrony of replication in sister salivary glands of Drosophila kikkawai

Abstract

Intergland synchrony of replication in the larval salivary glands of D. kikkawai bas been studied by ³H-thymidine pulse labelling and very light squashing. It is observed that there is a striking synchrony of replication between the 2 sister glands with respect to the position of the replicating nuclei and the frequency of different labelling patterns. There is also considerable synchrony within a gland where a group of neighbouring nuclei show similar kind of labelling. These observations suggest that the replication cycles of different polytene nuclei in the two sister salivary glands of a Iarva are developmentally determined.