In the most comprehensive analysis to date, researchers found that the shapes of fingerprints—whether they are circular, wavy, or winding—are influenced by the genes responsible for limb development instead of skin patterning. The study, presented January 6 in the journal Cell, could help scientists better understand the association between genes and phenotypical traits in humans.
"People may wonder why our team is working on fingerprints," says Sijia Wang, a geneticist at the Shanghai Institute of Nutrition and Health, of Chinese Academy of Sciences, and co-senior author on the paper. "We started the work purely out of curiosity. But later it turns out fingerprint pattern is associated with genes for limb growth, which are critical for fetal development. This provides another classic example of pleiotropy, when multiple phenotypes are interrelated to each other and are affected by the same genes." While fingerprints are unique to individuals, they are generally categorized into three types: arch, loop, and whorl. These furrows and ridges begin to form on a fetus' fingers and toes after the third month of pregnancy. Scientists have suspected that fingerprints have potentially evolved to help grab objects and sense their textures, but exactly how these patterns are formed remains unknown. Wang and colleagues scanned the DNA of more than 23,000 people across ethnic groups and found that at least 43 regions on the genome are associated with fingerprint patterns. One of the most influential regions appeared to be regulating the expression of a gene called EVI1, which is known for its role in embryonic limb development. To test their finding, the team modified the DNA of mice so their expression of EVI1 was turned down. They found that mice with downregulated EVI1 developed abnormal skin patterns on their digits compared with wild-type mice. Read more...
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