The appearance of Chimp is significantly different from humans, although the creature is close relative of our human beings. Recently, a paper published in Cell has revealed the molecular mechanisms that causes face structural differences between two species that have the same genetic background.

 
The researchers pointed out that the key point lies in how the gene involved in the genetic diversity is regulated, the level of the regulation and the time and location of it. In particular, the researchers found that human and chimp can express different level of proteins that have controls over facial growth including participation in the chin, nose length and skin pigmentation, etc. “Through researches, we try to understand the regulatory changes in the body’s DNA in the modern evolution, as well as how is this different from chimp; we are especially concerned with the craniofacial structures, which may help us to have bigger brains, have the ability of upright walking and the ability to make complex speech by using throat.” said professor Joanna Wysocka.

 
In the study, scientists mainly focused on the differences of DNA in the genome enhanced region in human and chimpanzee. This region includes chemical markers and DNA-binding proteins that controls the function of DNA. The researchers must obtain a special type of cell called cranial neural crest cell, which is formed 5-6 weeks after pregnancy. Through in-depth study, the researchers found two genes called PAX3 and PAX7 can affect the snout, shape and skin pigmentation of the test mice. Compared to human beings, chimps expressed a high level in those terms.

 
People that has lower PAX3 level than normal ones might suffer from Waardenburg syndrome. In comparison, PAX7 was thought to be involved in the formation of breaks and chin and compared to chimpanzees, humans have a higher expression level of this gene. Furthermore, the use of mice found that the overexpression of BMP4 in the cranial neural crest cells might promote an iconic shape change in the face, including the head and eye sunk.

 
“I believe through more research in the future, we can clarify more cell path that has control over facial shape.” commented Wysocka, one of the key researchers in the study.