A new study has found that genes which control limb development are responsible for fingerprints. It was assumed that fingerprints were determined by genes that are responsible for skin patterning. The research could help scientists understand phenotype and genotype in humans.
Study senior author Sijia Wang is a geneticist at the Shanghai Institute of Nutrition and Health of the Chinese Academy of Sciences.
“People may wonder why our team is working on fingerprints,” said Wang. “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.”
Although fingerprints are unique to individuals, they all follow the same basic patterns: arches, whorls and loops. Scientists have long thought that fingerprints may have emerged as a way to grip things better and sense textures of objects. They are known to develop during the third month of pregnancy, but this process remains a mystery.
The scientists used a sample of 23,000 people across ethnic groups and discovered at least 43 genomic regions associated with fingerprints. One of the most important regions is controlled by the expression of a gene called EVI1, a gene known for its embryonic limb development.
“We don’t know exactly how the genes shape fingerprint patterns, but it could be determined by the amount of strength from growth that’s put on an embryonic tissue called volar pads that plays an important role in the formation of different patterns of fingerprint,” said study co-first author Jinxi Li, a geneticist at the Human Phenome Institute at Fudan University in Shanghai.
Interestingly, different fingerprint types were also correlated to length of limbs and digits as well as genetic disorders.
“Many congenital genetic disorders are related to different dermatoglyphic patterns, such as fingerprints,” said Li. “Our study suggests that dermatoglyphic patterns are affected by crucial development genes, which provides a strong theoretical basis for this kind of pleiotropy.”
The study is published in the journal Cell.
By Zach Fitzner, Earth.com Staff Writer