PCDH11Y

PCDH11Y is a gene unique to Homo males that encodes Protocadherin 11Y, a protein that guides the development of nerve cells. PCDH11X, located on the X chromosome, is common, in both sexes, to humans and our nearest relative, the chimpanzee; however, PCDH11Y, located on the Y chromosome, is unique to males.[3]

PCDH11Y
Identifiers
Aliases	PCDH11Y, PCDH-PC, PCDH22, PCDHX, PCDHY, protocadherin 11 Y-linked
External IDs	OMIM: 400022 GeneCards: PCDH11Y
Gene location (Human) Chr. Y chromosome (human)[1] Band Yp11.2 Start 5,000,226 bp[1] End 5,742,224 bp[1]
Gene ontology Molecular function • calcium ion binding Cellular component • integral component of membrane • cell membrane • membrane • integral component of plasma membrane Biological process • homophilic cell adhesion via plasma membrane adhesion molecules • cell adhesion Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	83259	n/a
Ensembl	ENSG00000099715	n/a
UniProt	Q9BZA8	n/a
RefSeq (mRNA)	NM_001278619 NM_032971 NM_032972 NM_032973	n/a
RefSeq (protein)	NP_001265548 NP_116753 NP_116754 NP_116755	n/a
Location (UCSC)	Chr Y: 5 – 5.74 Mb	n/a
PubMed search	[2]	n/a
Wikidata
View/Edit Human

In terms of human evolution, it has been estimated that pcdh11x "gene jumped" from X to Y around three million years ago; coincident with increased human brain size and the first use of tools. Furthermore, around 120,000 to 200,000 years ago, the PCDH11Y gene was able to further transform, splitting in half and reversing its position.[4]

PCDH11X/Y are cadherin family genes. They make proteins, involved in signalling, that attach to the surface of nerve cells.[4] PCDH11X and PCDH11Y, respond in different ways to Retinoic acid, a chemical involved in the development of embryos. The acid stimulates the activity of PCDH11Y but suppresses PCDH11X. This is likely one of the explanations for the differences between the brains of men and women.[3]

Psychiatrist, professor Tim Crow, also believes the gene explains lateralisation. Humans have "lateralised" brains, in which the different sides became specialised for particular jobs. For instance 90% of people will use their right hands for fiddly tasks. A chimpanzee is just as likely to use either hand. It also explains why, for right-handed people, linguistic functions are concentrated on the left side of the brain.[3]