Synchronous replication of terminal regions of short arms in human X and Y chromosomes.

The replication profiles of terminal segments of short arms (p) of human X and Y chromosomes are analyzed with RBA-technique at high resolution. Both the terminal regions present yellow green fluorescence showing the early and synchronous replication pattern during S-phase of the cell cycle. This clearly demonstrates the identical nature and functional homology between the two regions which contribute to end pairing seen in meiotic prophase I.