Identical Twins Now Not So Identical

For years, science has been trying to determine if identical twins are identical in every way or if their DNA and genome could differentiate. Cases where twins have been separated at birth, not for the purposes of any study, have been of particular interest because there are a lot of environmental factors that now come into play. Leave it to forensic scientists, who have now determined a way to differentiate the DNA of identical twins with a new technique.

The new technique looks at DNA methylation, which is what changes the way in which genes are expressed, in a process called high resolution melt curve analysis, or HRMA. Paul Mathieson suggests that environmental factors are known to affect the way DNA methylation occurs in every individual, and even when twins are exposed to the same environment, they are creating different expression in their genome.

While the process of finding these differences was difficult, painstaking and extremely expensive, this new HRMA method is very cost effective and takes up much less time. The differences are ultimately shown in the differing heat signatures that are present for each individual. Hydrogen bonding is key in telling twins apart, because it is the hydrogen bonds that make up our DNA and causes differentiation that are looked at and studied. The more methylation that has occurred, the more hydrogen bonds need breaking and subsequently the higher the heat signature is for an individual. Each identical twin will have a specific number of bonds creating a specific heat signature and thus a new way to tell them apart.

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