PCDHY
Encyclopedia
PCDH11Y is a gene
unique to human males which competes for the title of the "language gene
." PCDH11Y is the gene for making 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 men.
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.
PCDH11X/Y are cadherin
family genes. They make proteins, involved in signalling, that attach to the surface
of nerve cells. PCDH11X and PCDH11Y, respond differently to Retinoic acid
, a chemical involved in the development of embryo
s. 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.
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.
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
unique to human males which competes for the title of the "language gene
Language gene
Language gene may refer to:*FOXP2, a protein found in mammals*PCDHY, a gene unique to human males...
." PCDH11Y is the gene for making Protocadherin
Protocadherin
Protocadherins were discovered by Shintaro Suzuki's group, when they used PCR to find new members of the cadherin family. The PCR fragments that corresponded to Protocadherins were found in vertebrate and invertebrate species...
11Y, a protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
that guides the development of nerve cells
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
. PCDH11X
PCDH11X
Protocadherin 11 X-linked, also known as PCDH11X, is a protein which in humans is encoded by the PCDH11X gene.- Function :This gene belongs to the protocadherin gene family, a subfamily of the cadherin superfamily...
located on the X chromosome
X chromosome
The X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals and is common in both males and females. It is a part of the XY sex-determination system and X0 sex-determination system...
is common, in both sexes, to humans and our nearest relative, the chimpanzee
Chimpanzee
Chimpanzee, sometimes colloquially chimp, is the common name for the two extant species of ape in the genus Pan. The Congo River forms the boundary between the native habitat of the two species:...
; however, PCDH11Y located on the Y chromosome
Y chromosome
The Y chromosome is one of the two sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 60 million base pairs...
, is unique to men.
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
Brain size
Brain size is one aspect of animal anatomy and evolution. Both overall brain size and the size of substructures have been analysed, and the question of links between size and functioning - particularly intelligence - has often proved controversial...
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.
PCDH11X/Y are cadherin
Cadherin
Cadherins are a class of type-1 transmembrane proteins. They play important roles in cell adhesion, ensuring that cells within tissues are bound together. They are dependent on calcium ions to function, hence their name.The cadherin superfamily includes cadherins, protocadherins, desmogleins, and...
family genes. They make proteins, involved in signalling, that attach to the surface
Transmembrane protein
A transmembrane protein is a protein that goes from one side of a membrane through to the other side of the membrane. Many TPs function as gateways or "loading docks" to deny or permit the transport of specific substances across the biological membrane, to get into the cell, or out of the cell as...
of nerve cells. PCDH11X and PCDH11Y, respond differently to Retinoic acid
Retinoic acid
Retinoic acid is a metabolite of vitamin A that mediates the functions of vitamin A required for growth and development. Retinoic acid is required in chordate animals which includes all higher animals from fishes to humans...
, a chemical involved in the development of embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s. 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.
Psychiatrist
Psychiatrist
A psychiatrist is a physician who specializes in the diagnosis and treatment of mental disorders. All psychiatrists are trained in diagnostic evaluation and in psychotherapy...
, professor Tim Crow
Tim Crow
Tim Crow is a British psychiatrist and researcher from Oxford. Much of his research is related to the causes of schizophrenia. He also has an interest in neurology and the evolutionary theory. He is the Honorary Director of the Prince of Wales International Centre for Research into Schizophrenia...
, also believes the gene explains lateralisation
Lateralization of brain function
A longitudinal fissure separates the human brain into two distinct cerebral hemispheres, connected by the corpus callosum. The sides resemble each other and each hemisphere's structure is generally mirrored by the other side. Yet despite the strong anatomical similarities, the functions of each...
. Humans have "lateralised" brains, in which the different sides became specialised for particular jobs. For instance 90% of people will use their right hands
Handedness
Handedness is a human attribute defined by unequal distribution of fine motor skills between the left and right hands. An individual who is more dexterous with the right hand is called right-handed and one who is more skilled with the left is said to be left-handed...
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.