Early DNA Synthesis in the X-chromosome of Pellia neesiana

In the present investigation DNA synthesis of X-chromosome of Pellia neesiana (n=9), Hepaticae, was studied by the use of the H3-thymidine autoradiography. 1. DNA in the heterochromatin of X-chromosome of female Pellia neesiana was found to replicate during the early and the middle stages of DNA synthetic phase. 2. DNA in the euchromatin of both X-chromosome and autosomes was found to replicate continuously from the early to the last stages of DNA synthetic phase. 3. DNA in the heterochromatin of X-chromosome was found to replicate mainly in the diffused state of heterochromatin during the early stage of DNA synthetic phase.