Identical twins, also known as monozygotic twins because they are derived from a single fertilized egg, as indicated by Science News, are often studied to determine the origin of specific traits, diseases or conditions, whether due to genetics. or the result of their environment. This study looked specifically at 381 pairs of identical twins and found that 38 of the pairs have identical genetics, but that most pairs have some differences in DNA that originated very early in their development.Thirty-nine of the pairs had more than 100 changes between the twins and the study suggests that these DNA differences occur when the embryo is divided to form two in early development or shortly after the embryo is divided. This suggests that this embryo cleavage is not as clean or neat as previously thought, leading to the DNA changes seen.
Science News notes that some twins are formed when a single cell or a small group of cells separates from the embryo, and it is the number of cells that make up a twin that can determine the genetic differences between him and his other twins. . The more uneven tears of the embryo occur, the greater the number of genetic differences between twins.
“This is an extraordinary, exciting and informative effort to point to early cellular mechanisms that explain genetic differences between MZ (monozygotic) twins,” California State University, Fullerton, professor of psychology, Nancy Segal, told CNN. “It is well known that MZ twins do not have perfect similarity and that some differences may reflect genetic differences. The current study provides new information on the source of the MZ twin differences.”Segal said the study shows that “some twin models underestimate genetic effects and require revision.”
For more twins, check out our list of the best movie twins ever, and if you want more DNA science, read this story on how a new study reveals that most Vikings were not blonde or blue-eyed.
Wesley LeBlanc is a freelance news writer and guide for IGN. You can follow him Twitter @LeBlancWes.