The pseudoautosomal boundary in man is defined by an Alu repeat sequence inserted on the Y chromosome.
The Y chromosome, which in man determines the male sex, is composed of two functionally distinct regions. The pseudoautosomal region is shared between the X and Y chromosome and is probably required for the correct segregation of the sex chromosomes during male meiosis. The second region includes the sex-determining gene(s), the presence of which is necessary for the development of testes. The two regions have contrasting genetic properties: the pseudoautosomal region recombines between the X and Y chromosome; the Y-specific region must avoid recombination otherwise the chromosomal basis of sex-determination breaks down. The pseudoautosomal region is bounded at the distal end by the telomere and at the proximal end by X- and Y-specific DNA. We have found that the proximal boundary was formed by the insertion of an Alu sequence on the Y chromosome early in the primate lineage. Proximal to the Alu insertion there is a small region where similarity between the X and Y chromosomes is reduced and which is no longer subject to recombination.
Ellis
N A
NA
Imperial Cancer Research Fund, London, UK.
Goodfellow
P J
PJ
Pym
B
B
Smith
M
M
Palmer
M
M
Frischauf
A M
AM
Goodfellow
P N
PN
D001483:Base Sequence; D003001:Cloning, Molecular; D015342:DNA Probes; D005260:Female; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D014998:Y Chromosome
D015342:DNA Probes