BEIJING -- A team of Chinese zoologists have identified a genetic source making the coat color of some giant pandas appear unusually brown and white.

The world's first brown panda was discovered in 1985 in the Qinling Mountains in Northwest China's Shaanxi province. All recorded photographs of the wild brown pandas were taken in the area. A recent adopted one is the male brown-and-white panda Qizai born in 2009.

The scientists from the Institute of Zoology under the Chinese Academy of Sciences sequenced the genomes of three panda families connected with Qizai, as well as other 29 pandas in black and white check.

They found that the mutation in a gene called Bace2 that encodes a precursor protein's cleaving enzyme is the most likely genetic basis for brown-and-white coat color, according to a study published on Monday in the U.S. Proceedings of the National Academy of Sciences.

A further genome analysis on 192 captive black-and-white pandas revealed that none of them carry such a mutation. Also, a genetically engineered mouse model with this mutation developed light fur, according to the study.

The results provide unique insights into the genetic basis of coat color variation in wild animals and will guide scientific breeding of the rare brown pandas, said the researchers.