Differential expression pattern of XqPAR-linked genes SYBL1 and IL9R correlates with the structure and evolution of the region.
The recently discovered second pseudoautosomal region (XqPAR) contains at least two genes, IL9R and SYBL1. Recent findings show that, like XpPAR genes, IL9R escapes X inactivation and its Y allele is also expressed, but SYBL1 seems to act like an X-linked gene, expressed from the active X chromosome but not from the inactive X or Y. Here we show that differences are also seen in the evolution of the sex chromosome locations of IL9R and SYBL1. IL9R is known to be autosomal in mice, and is X-linked only in primates. SYBL1, however, has been found to be on the X chromosome in all mammals tested, from marsupials to humans. Both genes were duplicated on the Y homologue of the terminal portion of the X chromosome during the evolution of Homo sapiens from other higher primates. The inactivation pattern of SYBL1 may be correlated with its longer history of X linkage, and at a more centromeric chromosomal position during evolution; the more recent X linkage and more telomeric position of the IL9R gene may explain its autosomal, 'uninactivated' transcriptional status.
D'Esposito
M
M
International Institute of Genetics and Biophysics, CNR, Naples, Italy.
Matarazzo
M R
MR
Ciccodicola
A
A
Strazzullo
M
M
Mazzarella
R
R
Quaderi
N A
NA
Fujiwara
H
H
Ko
M S
MS
Rowe
L B
LB
Ricco
A
A
Archidiacono
N
N
Rocchi
M
M
Schlessinger
D
D
D'Urso
M
M
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D018076:DNA, Complementary; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D016678:Genome; D006801:Humans; D008394:Marsupialia / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D011323:Primates / Q000235:genetics; D050683:R-SNARE Proteins; D018123:Receptors, Interleukin / Q000235:genetics*; D053651:Receptors, Interleukin-9; D014960:X Chromosome
D018076:DNA, Complementary; C508045:IL9R protein, human; D008565:Membrane Proteins; D050683:R-SNARE Proteins; D018123:Receptors, Interleukin; D053651:Receptors, Interleukin-9; C496927:Sybl1 protein, mouse; C121241:VAMP7 protein, human