Scientists from Peking University, Beijing in May 2013 discovered that a change in single amino acid (A477V) in one pigmentation relate gene (SLC45A2) is the cause of white fur or sepia brown stripes in some tigers. The scientists studied 16 captive white tigers from three different parents to come up with the conclusion.
As per the scientists, two types of melanin namely pheomelanin and eumelanin are used for identifying the color of fur, eye and stripes of the tiger. In case of the white tigers, pheomelanin that produces red and yellow color is affected. As per the research, the point mutation in the amino acid blocks a particular channel partially; as a result of this blockage yellow pigment forming process is affected. Same type of mutation in pigmentation-related gene (SLC45A2) causes light skin colour in modern Europeans as well as mouse, chicken and horse too.
As per the study, human often force the tigers to inbreed for increasing the number of white tigers in zoos. This type of forced inbreeding may create some health side effects in the tigers as it has been a reason of health ailments in humans. In tigers this forced inbreeding has resulted in human-induced inbreeding has resulted in premature death, stillbirth and deformities.
White tigers are a part of the genetic diversity of the tigers, which is caused due to mutation and are worth conserving. The findings of the research was published in Thursday in the Current Biology journal. The study was conducted under the leadership of Shu Jin Lau of Peking University.