Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
, 119 (3), 267-75

Inactivation Status of PCDH11X: Sexual Dimorphisms in Gene Expression Levels in Brain

Comparative Study

Inactivation Status of PCDH11X: Sexual Dimorphisms in Gene Expression Levels in Brain

Alexandra M Lopes et al. Hum Genet.


Genes escaping X-inactivation are predicted to contribute to differences in gene dosage between the sexes and are the prime candidates for being involved in the phenotype observed in individuals with X chromosome aneuploidies. Of particular interest is ProtocadherinX (PCDH11X or PCDHX), a recently described gene expressed in brain. In humans, PCDH11X has a homologue on the Y chromosome and is predicted to escape from X-inactivation. Employing bisulphite sequencing analysis we found absence of CpG island methylation on both the active and the inactive X chromosomes, providing a strong indication that PCDH11X escapes inactivation in humans. Furthermore, a sexual dimorphism in levels of expression in brain tissue was observed by quantitative real-time PCR, with females presenting an up to 2-fold excess in the abundance of PCDH11X transcripts. We relate these findings to sexually dimorphic traits in the human brain. Interestingly, PCDH11X/Y gene pair is unique to Homo sapiens, since the X-linked gene was transposed to the Y chromosome after the human-chimpanzee lineages split. Although no differences in promoter methylation were found between humans and chimpanzees, evidence of an upregulation of PCDH11X in humans deserves further investigation.

Similar articles

See all similar articles

Cited by 18 articles

See all "Cited by" articles


    1. Am J Hum Genet. 1997 Jun;60(6):1333-43 - PubMed
    1. Nature. 2005 Mar 17;434(7031):400-4 - PubMed
    1. Hum Mol Genet. 1996 Mar;5(3):391-401 - PubMed
    1. FEBS Lett. 2004 Jun 1;567(1):121-8 - PubMed
    1. BMC Bioinformatics. 2003 Sep 8;4:37 - PubMed

Publication types

LinkOut - more resources