Monday, December 10, 2012

The Truth of Dimples!


Dimples are often view as beauty and loveliness marks; however, the truth of dimples is actually resulting in genetic defects.  Most check dimples are result in genetic defects of shortened muscle- which pulls the around skin instead of around bones. It is inherited facial traits that are passed from one generation to the next.  If both parents have dimple traits the children have 50-100% chance of inheriting the gene, if only one parent has dimple traits the chance of the children inheriting the genes are 50%. Dimples can be passed down through multiple generations - Penetrance is the frequency of which a heritable trait is passed down. Many people are the carrier but didn't show the associate traits, the traits will be passing to a successive generation.  Apart from that, sometimes the dimples may cause by spontaneous mutations that result in a dent in the cheek or a cleft chin which leads to dimples. 

Monday, December 3, 2012

Genetic of eye color

                                                     Credit to: 

Have you ever wondering why your eye color is brown, blue, green or grey? Most people will say this is because of dominant and recessive traits, where brown eye color being the dominant one. However, our eyes color is far more complicate than that, eyes color is determine by multi-gene trait, not a single-gene trait.  OCA2 and HERC2 genes are mainly responsible for eye color. OCA2 locates on chromosome 15 and controls almost ¾ of the blue-brown color spectrum. These genes control the amount of melanin (type of pigments) inside the iris. Melanin is produce in a specialized cells call melanocytes, which store in intracellular compartments known as melanosomes. A number of other genes (TYRP1, ASIP and ALC42A5) also function in the melanin pathway and shift the total amount of melanin present in the iris. Eye color is arranged from lightest blue to darker brown and everything in between; Brown contains highest level of melanin and blue contains minimal melanin. Red eyes color have no melanin so there is no pigment in the iris, the red color comes from blood vessels. In addition our eyes color change over time period, this is due to decrease or increase stroma in the pigment granules. A little fun fact, people with blue color eyes come from same ancestor.