Unraveling DNA Replication For The First Time On Video
(Photo : Medical Instittution/YouTube screenshot)
Scientists have been trying to figure out the mystery of this hereditary DNA replication. Now, they have captured a video of it and they are more puzzled than before.
Stephen Kowalczyzkowski, a molecular genetics professor at the University of California, Davis, said that it is a different way of thinking about replication that raises new questions. He further said that it is a real paradigm shift and undermines a great deal of what is in the textbooks.
DNA replication in molecular biology is defined as the biological process of generating two identical replicas of DNA from the original DNA molecule. This exists in all living organism and is attributed as the biological inheritance. DNA is composed of a double helix of two complementary strands. In times of replication, the strands will separate. The strand of one original DNA molecule could act as a template for the regeneration, a process known as semiconservative replication.
The DNA replication begins at the origins of replication within a cell. There is an unwinding of DNA at the origin and proteins are linked with the replication fork to aid in the DNA synthesis. This DNA replication happens during the S-stage of interphase.
In the video, the scientists were surprised because the replication stopped suddenly and shifted at varying pace. Professor Kowalczyzkowski said that the speed can vary about 10-fold, and the two strands also replicated at various speeds. At times, the replication stalled on one strand while taking place on the other. He also said that there is no coordination between the strands and they are completely autonomous, as Newsweek noted.
They found that the three enzymes, namely the helicase, primase and polymerase, are not always in sync. The helicase keeps on unzipping the helix even if the polymerase stops its replication. This could make the half-helix of DNA exposed and might be damaged. It is theorized that the errors in replication DNA could result in genetic abnormalities and could lead to diseases.