Nucleic Acids Research, 1988, Vol. 16, No. 12 5361-5377
© 1988
Articles |
A long range restriction map of the pseudoautosomal region by partial digest PFGE analysis from the telomere
Imperial Cancer Research Fund, Lincoln's Inn Fields PO Box 123, London WC2A 3PX, UK
Received March 31, 1988. Revised May 13, 1988. Accepted May 13, 1988.
The analysis of partial digestion products extending from the telomere of the human X and Y chromosomes, visualised by hybridisation to a probe located close to the telomere, was used to establish a restriction map of the pseudoautosomal region. In this highly polymorphic region with a 10-fold elevated recombination frequency in males we identified site or methylation differences between 7 different male and female cell lines and tissues, and derived an estimate of the size of the pseudoautosomal region of approximately 3 Megabases by comparing X and Y chromosomes. This size correlates well with previous estimates based on genetic arguments and argues against a strongly enhanced rate of exchange near telomeres in general. We identified a CpG rich and hypomethylated region within 500 kbp from the telomere, which might reflect structural features of mammalian telomeres, and a small number of (additional) CpG islands, which might represent candidate genes for the Turner phenotype in XO females.