When you think of fingerprints, what comes to mind? Is it the fingerprint taking shot in the criminal investigation movie, or the mother who broke your finger to count "buckets" and "dustpans" when you were a child? There are many mysteries about fingerprints. But historically, little has been known about the biological mechanisms of fingerprint formation.
In order to solve this mystery, the team of wang sijia researchers of the Shanghai Institute of Nutrition and Health of the Chinese Academy of Sciences, the team of Professor Dennis Hutton of the University of Edinburgh, the team of academicians of the Chinese Academy of Sciences and professor Jin Li of Fudan University, and more than ten scientific research institutions inside and outside the United Nations have conducted in-depth research on this. After analyzing the relationship between nearly one million genetic loci and fingerprint patterns in humans, they found that limb development-related genes play a key role in the formation of fingerprint patterns, which is expected to provide new ideas for the early identification and screening of specific diseases through skin pattern phenotypes.
On January 7, 2022, Beijing time, the relevant research results were published in the international authoritative academic journal "Cell".
[The longer the little finger, the shorter the palm length, the more two-handed bucket pattern]
"Asian people have more fingerprints and fewer buckets. In addition to these two more common, there is also a bow type. Wang Sijia said that the fingerprint pattern is formed in the early stage of embryonic development, and the type remains unchanged for life.
Bucket type (left) and mi. Photo by Huang Haihua
The researchers conducted the largest genome-wide correlation analysis of fingerprint patterns to date for more than 23,000 individuals, from which 43 genetic loci associated with human fingerprint patterns were identified.
Surprisingly, although fingerprints are on the skin, these genes are abundantly present in pathways related to limb development function rather than skin development.
Based on experimental observations of mouse animal models and human embryonic tissue, the team found that it is the mesenchymal cells expressed in limb development that support the EVI1 gene to shape limbs and fingers, rather than epithelial cells during skin development. This further seals the fingerprint-related genes by regulating limb development to influence the formation of fingerprint patterns.
The study also found a close correlation between the proportion of fingerprint patterns and finger lengths, such as the longer the little finger, the shorter the palm length, the more double-handed bucket patterns, and the longer the distal knuckles of the index finger (where the fingerprint is formed), the fewer the bucket patterns.
【Skin pattern phenotype can assist in screening for Down syndrome】
Previously, the scientific community has found an association between different skin patterns and many congenital genetic diseases. For example, patients with Down syndrome may have features such as broken palms and arched toes of the foot; for example, in the 1960s, studies have found that leukemia patients have more bucket fingerprint patterns. Although this is not a predictive model, no one knows the reason behind it.
This study provides an important theoretical basis for the association between fingerprint patterns and disease health, making it possible to "see the hand to know the disease" in the future.
Researchers such as Wang Sijia (third from left) and Li Jinxi (second from left), the first author of the paper, discuss. Qi Xinru photographed
"We have previously obtained the invention patent of 'Down Syndrome Skin Pattern Auxiliary Screening', which is also the first Down Syndrome Auxiliary Screening System based on skin pattern phenotype." Wang Sijia introduced that the team is cooperating with medical institutions such as the Children's Hospital of Fudan University, hoping to apply the relevant research results to the early screening of neonatal congenital diseases as soon as possible to achieve early diagnosis and treatment.
Zhang Haiguo, the first author of the paper and a professor at the School of Life Sciences of Fudan University, introduced that in the past, fingerprints have been collected with ink, and the research team has independently developed an electronic fingerprint collector.
["Navigation Map" brings a huge number of "question marks"]
"This is a classic case of human phenotypic group research, and it is of great significance." Jin Li, co-corresponding author of the paper and chief scientist of the Human Phenotype Group Big Science Program, believes that this achievement not only discovered for the first time a strong correlation between fingerprint patterns and limb phenotypes, but also clarified the genes behind fingerprints, but also showed that the research idea of "human phenomics" is effective, a breakthrough in research strategies, and the establishment of a research paradigm.
If genes are an intrinsic code, the phenotype that interacts with genes and the environment is the outward expression of the code. The so-called human phenotype group is the collection of all the biological characteristics of the human body.
"Why are everyone's fingerprints different, why koala bears have fingerprints that are very similar to people... These interesting questions are yet to be explored. Li Jinxi, the first author of the paper and a postdoctoral fellow at the Institute of Human Phenotype Group of Fudan University, said.
Fudan University is vigorously promoting the human phenotype group big science plan with domestic and foreign institutions, which will collect phenotypic data from a considerable group of volunteers, and then discover and analyze the strong associations between phenotypes, especially those strong associations between phenotypes that scientists have not noticed and are closely related to human health, and finally form a "navigation map" composed of various strong associations, providing new guidance and direction for future life and health research.
At present, based on the cohort study of more than 800 people and nearly 30,000 phenotypes measured by Fudan University in Shanghai, a team of Chinese scientists from different institutions has preliminarily drawn the world's first "human phenotypic group navigation map", and found more than 1.5 million strong associations, of which 39% are cross-field strong associations, most of which are the first discoveries in the scientific community.
"To become a source of innovation with global influence, Shanghai must not only solve scientific problems, but also propose new scientific problems." This 'navigation map' brings a huge number of 'question marks' waiting for scientists to study and crack, which is also one of our important tasks in the next step." Jin Li said.