Your skin ‘sees’ light

Step into the sun and it’s not just your eyes that sense the light. Your skin contains photoreceptors like those in the retina, allowing it to mount an immediate defence against damaging ultraviolet radiation.

The skin tans by producing melanin, a pigment that protects DNA from dangerous UV rays. We already know that one component of the UV rays – called UVB – ramps up melanin production a few days after sun exposure in response to DNA damage in the skin. But another component of the radiation – UVA – encourages pigment production within minutes.

Scientists analysed the genes expressed in melanocytes, the cells responsible for melanin production, and discovered that the cells also make rhodopsin, a light-sensitive chemical found in the retina.

When the team shone UVA light on melanocytes, they saw melanin production rise. Within 24 hours there was a five-fold increase in the production of the pigment. Knocking out the gene responsible for making rhodopsin in melanocytes blocked this immediate response to UVA.

Unfortunately, immediate tanning does not protect against UV-induced sunburn or DNA damage. Learn more here.

Advertisements

Tags: , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


%d bloggers like this: