Most of the science we presently comprehend is based on the trust that the natural state of inclination is to assume orderliness, even in the face of inevitably increasing entropy. While there exist laws of thermodynamics construing to explain how the eventual entropy of the universe will embark upon a point where all energy would be converted into destructive over constructive, there exist tiny atoms that rebel seemingly against the notion of a lack of patterned existence.
Orderliness has been worshipped for the organised learning it provides to us. Patterns are hunted for, sequences are discovered, and catalogues of categorisation are developed in order to attain a comfortable scale of organisation in the world of science and beyond.
One of the very important spheres of science speaks about us. Despite the amazingly varied functions assumed by the cells of our body, they’re all controlled by the same master ship: the DNA. In all of biology and relevant parallel fields, there have been observed and established processes that define the central dogma of life.
But every now and then, the most concrete standardizations are rocked beyond the available human capacity to believe. And the best of us realise that we have a long way to go.
Whether or not you know about the processes, is not the reason why I am writing to any of you. I am writing to you to make you realise that we have reached a point in one of our sciences where the fundamentals have been quaked – and this concerns every cell of your body.
The notion of procedural orderliness we have pursued so relentless in cell biology has been crumbled by one of the shortest videos any of us have ever invested in. But before I can reveal to you what is already magically accessible now, let’s ensure we are both on the same stage of central dogma – DNA replication.
Essentially, DNA replication is a process that involves doubling the amount of DNA a cell holds, simply to create two sets of the genetic material that can then be each assigned their own cell.
In order to appreciate the characteristic pain of discovery mechanism of a fact that sounds so obvious post establishment, allow me to mention how the final model of replication was verified from amongst many others. 3 of which were considered to be the ultimate contenders viz. Semi-Conservative Model, Conservative Model and the Dispersive Model. These models were based to hypothesize the pattern of inheritance of parent strands of DNA during the process of replication. Of these, the famous Meselson-Stahl experiment helped verify the Semi-Conservative Model of DNA replication.
Even as these groups of scientists were debating and contending for accuracy, all three models were based on the simple obvious presumption that the 2 strands that comprise the DNA double helix undergo replication in a synchronised fashion.
59 years later, here we are, watching a film (Video Imaging of DNA Replication) that quietly lets us know that chaos is the preferred mode for DNA replication and that the 2 strands choose to behave almost independently of each other during the process of replication (and perhaps even beyond it, if we choose to realise how far we are from understanding the dynamics of the very basic constituent that validates life). The only obvious bit about any of the replication processes we believe we have established in context so far is that they might be inaccurate.
So what’s the big deal about this lack of co-ordination?
A range of genetic disorders that are observed in humans and other species demand understanding of the genetic code, and the processes that synthesize life viz. replication, transcription and translation. Replication involves creation of new daughter DNA from pre-existing parental DNA, transcription involves formation of RNA from DNA, and translation – the process that most concerns us morphologically and functionally involves protein synthesis from mRNA templates.
An error during any of these processes results in inaccurate transmission of information that the DNA is a storehouse of. These inaccuracies occur in the form of ‘mutations’ – and these mutations are often the culprits of several genetic diseases that affect the human population. The presumption that co-ordination between the replication of 2 DNA strands of opposite polarity has served as the basis of our understanding of the astonishingly controlled rate of mutations.
Our cells are only wrong once per 10 million base pairs per those that are replicated.
This number was well adjusted into the larger picture of organised replication – but now that the process has been stripped to a far greater extent, the low mutation rate is inexplicable.
Somehow, the 2 strands replicate completely independently of each other and still account for the perfect match!
The science behind compatibility has come to a dynamic stand-still, all over again. Take a seat, and have a look at this video of dyed DNA strands of E. coli that have rendered us directionless.
Author: Aastha Munjal Date of Publishing: 22nd Jun 2017 Artwork: Mr Thelonious "Charles" Babbage first image of DNA under the microscope