Why left-handed people appeared: researchers are supposedly closer to solving the mystery of the dominance of left-handedness, having identified a potential genetic mechanism of this phenomenon.
This information was reported by the Inverse resource, reports URA-Inform.
What influences the formation of left-handers?
One of the key factors in determining hand dominance is related to brain asymmetry: if the left hemisphere is dominant, a person becomes right-handed, and if the right hemisphere is dominant, a person becomes right-handed. lefties. This asymmetry begins to appear during embryonic development, indicating its genetic nature.
The work of scientists
Scientific research has been enhanced by the use of the human exome, which is the sequence of all protein-coding regions of the genome. Scientists from the Netherlands analyzed data collected in the UK Biobank on 300 thousand right- and left-handed people, looking for rare genetic variants associated with hand dominance. And as a result of this search, they discovered a potential «culprit» — TUBB4B gene. This gene encodes a protein known as tubulin, which plays a role in the formation of cylindrical microtubules.
Bottom Line
According to the study, the TUBB4B gene had the most significant association with left-handedness, indicating the importance of microtubules in the asymmetry of the human brain that determines hand dominance.
Although microtubules are the smallest cellular structures, they can have a significant influence on the formation of hand dominance. For example, they are involved in the formation of cilia and cellular organelles that provide movement. These microstructures may be a key factor in the formation of asymmetry in entire cells, which in turn affects brain development. Thus, scientists have answered the question of why left-handers appeared.
Another feature of left-handers
Interestingly, left-handers have the genetic variant TUBB4B, responsible for various tubulins, is much more common than in right-handed people, highlighting its connection with left-hand dominance. However, not all left-handers were found to have this rare genetic variant, indicating the complex and multicomponent nature of this phenomenon. In fact, this makes left-handers special people in their own way, who can be very different from others.
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