Abstract
Dermatoglyphics is the study of fingerprints and ridges in our palms and soles. Fingerprints are critical areas of interest under research as they are unique and reveal an individual’s true identity. However, only a little is known about the reason behind the variation of fingerprint patterns. A recent study by the researchers at the Shanghai Institute of Nutrition and Health has revealed that genes involved in limb development influence the fingerprint patterns in humans.
The Different Fingerprint Patterns
Fingerprints are the patterns formed by ridges on the surface of our fingertips, palms, and the soles of our feet.
The number, shape, size, and position of the ridges do not change even when we grow up.
The patterns are contrasting for every individual.
It is fascinating that no two fingerprints can be the same, even in the case of twins.
The ridges on our hands and feet develop in the growing fetus from approximately 8 - 18 weeks of embryonic development.
The fingerprints are generally classified into three types: Whorls, Loops, and Arches. Loops represent staple-shaped ridges.
Image: Types of fingerprints
They are further organized into radial, ulnar, double, and central pocket loops.
The most common pattern is the loops, constituting 65% of the total fingerprint patterns. At the same time, the arches are the least common pattern.
The Genes Involved In Limb Development
The limbs develop from a circular structure called limb bud in the embryo.
The limb bud develops during the 4-8 weeks of embryonic development. After the eighth week, the limbs begin to enlarge in size.
The BMP4 Gene
The BMP4 gene contains instructions for producing bone morphogenetic protein 4.
It regulates the formation of limbs and is essential for osteoblast (bone cells) differentiation.
Did You Know: The BMP4 gene contributes to Achilles Tendinopathy Risk
The EVI1 Gene
The EVI1 gene produces an essential protein for appropriate murine and human development.
They are also responsible for limb development and oocyte development (egg cells) in the ovary.
The Influence Of Limb Development Genes - The Study
The study led by Wang and his colleagues found that limb development genes influence the variations in human fingerprint patterns.
The study was published in the journal of Cell Press and reported that the genes underlying limb development are not linked to skin formation but rather to fingerprint formation.
The team began by scanning the DNA of 23,000 participants to detect the genetic basis of the finger patterns and found that at least 43 genomic regions were related to limb development.
The team concentrated on the EVI1 gene - a primary limb development gene in humans to confirm the finding.
But, first, they modified the expression of EVI1 in mice.
They found that the mice with altered EVI1 levels developed abnormal skin patterns compared to normal mice.
The finding suggests that EVI1 is responsible for influencing fingerprint types in humans and hence holds up the idea that fingerprint patterns are related to finger length.
The exact mechanism by how the genes determine the fingerprint patterns is still unknown.
But research suggests that the shapes of the volar pads influence where and what type of fingerprint forms.
Volar pads are transient swellings of tissue on the palmar surface of the hands and soles of the feet of the developing baby.
Summary
- Fingerprints are impressions formed by the ridges on our hands and feet. They have been widely used for personal identification purposes due to their uniqueness and diversity between different individuals.
- The mechanism by which the fingerprint patterns are different for each individual and the variation in the patterns is still unknown.
- A recent study has reported that the genes involved in limb development influence the shapes of fingerprints.
References
https://www.sciencedaily.com/releases/2022/01/220106111552.htm
https://hastingsmuseum.org/wp-content/uploads/2020/05/Fingerprint-Info-Activities.pdf
