Chromosome Y

The human Y chromosome is only one third as big as the human X chromosome and represents almost 2% of the total DNA in cells. Together with the X chromosome it builds one of the 23 pairs of human chromosomes. A lot of the linked genes on the Y chromosome have no analogues on the X chromosome. These genes are mainly necessary for sperm production.


  • sex chromosome
  • about 58,000,000 base pairs
  • about 307 genes

Gene examples of chromosome Y:

The SRY (sex-determining region Y) gene: This gene encodes a protein that initiates male sex determination. Mutations in this gene give rise to females with one X and one Y chromosome (Swyer syndrome). A translocation (rearrangements of genetic material between chromosomes) of parts of the Y chromosome, containing this gene to the X chromosome, causes males with two X chromosomes (XX male syndrome).

DAZ1-4: These genes build the DAZ gene family and are candidates for the azoospermia factor (AZF). Their production is important for the production of sperm.

The chromosome Y image

The whole chromosome Y image has a width of 3500 px and a height of 16522 px. It is too big to display here but you can download the chromosome Y image. A 200 px wide overview of the chromosome can be seen on the right (bottom). Additionally, we show some details out of the original sized chromosome picture below.

Image details (examples):