Skin color is one of the most visible and variable traits among humans, and scientists have always been curious about how this variation evolved. A study of various Hispanic populations has now identified new genetic variations associated with skin color.
A study published in the journal Nature Communications found that variations in lighter skin in Eurasian humans evolved independently of differing genetic backgrounds.
A genetic study analyzed the pigmentation of more than 6,000 Hispanics who are of mixed Native American, European and African ancestry.
In the article estet-portal.com you can get acquainted in detail with the results of a genetic study of the molecular conditionality of the color of the skin, eyes and hair.
Asians and Americans: A Genetic Study of Differences
It is well known that Native Americans are genetically closely related to East Asian peoples, the original settlement of America occurred 15-20,000 years ago as a result of migration from Eastern Siberia to North America. As a result, genetic variation among Native Americans often overlaps with East Asians.
This study identifies five new related regions of the genome, including skin, eye and hair color.
The genes that affect skin color in Europeans have been extensively studied, but researchers have identified an important variation in the MFSD12 gene uniquely seen in East Asians and Native Americans.
The work demonstrates that lighter skin color evolved independently in Europe and East Asia. This gene was under strong natural selection in East Asia, possibly as a result of adaptation to changes in sunlight and ultraviolet radiation.
Follow us on Facebook
Genome study of the influence of the genome on skin and eye color
Just recently, scientists published the first major study on the genes associated with skin tone diversity in Africa. It is generally believed that the differences in pigmentation among Hispanics arise mainly from the varying degrees of European or African ancestry of people. But new research shows that there are differences inherited from their native ancestors.
The pigment melanin determines the color of hair, skin and eyes.
The MFSD12 gene affects how melanin is produced and stored in the skin, thereby affecting skin color.
In addition to the change in skin tone, the researchers also noted a wide variation in eye color among Hispanics. Just like skin color, early studies of eye color were European-focused and mostly focused on the difference between blue and brown eyes. But the authors demonstrate that eye color is a broad continuum, and by studying the more subtle variations from brown to black, scientists have found two new genes associated with these characteristics.
Study results help explain Hispanic skin, hair, and eye color changes, shed light on human evolution, and provide insight into genetic risk factors for conditions such as skin cancer.
Fitzpatrick skin phototypes: methods for correcting pigmentation disorders
Immunohistochemical analysis of MFSD12 protein expression in human scalp epidermis
During a genetic study, MFSD12 expression (green fluorescence) was found in many skin cell types (a, b). MFSD12 expression levels were higher in melanocytes (identified with anti-melanocyte antibody in red fluorescence) than in adjacent keratinocytes (green only).
Co-localization of both MFSD12 and melanocyte-specific protein gp100 can be seen in yellow/orange fluorescence (arrow). Keratinocytes in the scalp hair follicle also expressed MFSD12 (green only). In contrast to skin, MFSD12 expression was not detected in hair melanocytes (visible as red fluorescence indicating gp100 protein expression only) (c). Positive control (human kidney). There is low expression of MFSD12 in renal tubular cells (d).
Lack of genomic variation as an indicator of molecular adaptation
Given the evidence that solar radiation contributed to the diversity of certain genomic regions in Old World populations, it is interesting that scientists have not found pigmentation variants that are specific to America. On the American continent, there is a significant variation in solar radiation levels, since its territory extends along the north-south axis, covering the circumpolar and equatorial latitudes.
However, Native Americans do not show changes in skin pigmentation as seen in Old World populations living at similar latitudes. It has been suggested that this difference between continents may be due to cultural adaptations, environmental factors, or another biological adaptation mechanism. It is possible that the lack of new genetic adaptations to solar radiation levels in the Americas may be due to the relatively recent settlement of the New World, which began about 15,000 years ago.
Human physical diversity has fascinated biologists for centuries, and despite the discovery of hundreds of genes associated with such variation, much remains to be understood to get a fuller picture.
Thank you for staying with estet-portal.com. Read other interesting articles in the "Dermatology" section. You may be interested in What determines the synthesis of melanin and how to identify its deficiency
Share:
Add a comment