This write-up was for a writing assignment in Coursera.com MOOC (Massive Open Online Course) , English Composition I: Achieving Expertise offerd from Duke University. There were four assignments, I submitted first two of them and later became very busy with my M.S. thesis work. The second assignment was to select a random picture and writing an explanation regarding what it offer on achieving expertise.
Bioinformatics is a multidisciplinary subject which uses computational techniques employing various mathematical and statistical methods to answer biological questions. One important domain of Bioinformatics is genome analysis and one smoky question it tries to answer is how to find origin of DNA replication site. One expert bioinformatician might want to answer this question. Above image is a cartoon which illustrate this situation that some complex analysis is required to solve this puzzle.
Here, title of the image is “Where in the Genome Does DNA Replication Begin?” (1). This is a cartoon drawn by Randall Christopher, a visiting artist of coursera.org massive open online course (MOOC) Bioinformatics Algorithm I, 2013-14 session. This was taken from week one part of a cartoon series which is connected with course content.
In this picture, two men are walking in an island. The island is small and a blue sea is surrounding around it. There is an ancient ship floating on the sea in background. The island have a bunch of coconut trees, ordered in two lines side-by-side. These two line of trees are of varying length and they form a helical pattern. In front of the image, a box is half-buried in the sea-beach. A text is written outside of the box and that is “DNAA”. Abizarre, large golden bug is sitting on top of the box. A cryptic message is written on the body of the bug in English alphabet but they do not sense anything meaningful to the reader.
These two man are walking in opposite direction in the middle of the canvas. It can be assumed that the they have reached the island by travelling through the ship behind them. The front man is dressed like western character in Hollywood film and the man behind him is wearing pirate-like dress. One of his eye is covered by black bandana. Their foot-step formed a Greek ‘theta’ (ө) like circular path, although the front half of that ‘theta’ is smaller in area-size. Within the smaller half of theta-like-path they are strolling through, there are three wooden box situated which also have the text ‘DNAA’written on their outside wall. These two people’s body-gesture indicates that they are on a search for something hidden in this path. Some flies are flying on top of their head.
To explicate this image, the title also needed to be understood clearly. DNA is found in all living cell (with some exceptions like mature red blood cell) which is chemically called deoxyribonucleic acid and it is the information carrying component of the cell. The DNA functions as blueprint of life. Genome is the collection of whole DNA sequence which is written using four alphabets, namely A, T, G and C. Replication is the copying mechanism of DNA during cellular division. DNA is a double stranded molecule and there is a specific point where replication begin by splitting two strands. This splitting event form a small loop in the DNA molecule and replication starts in opposite direction. In ancient single cellular (eg. bacteria) cases, DNA is a circular molecule and when the replication begins, the size of loop increase. By this process, an imbalanced Greek theta shape of DNA is formed. In this image, the circular path is depicting DNA molecule. This conjecture is also corroborated by the helical shape of
coconut trees in background, as because we know that DNA is a helical molecule. The two ‘wildly-dressed’ investigators searching for something in the pierced-stranded-loop of the circular DNA, smaller-half of theta, and this is depicting their search for origin of replication.
Another important element in this image is DNAA boxes within the loop. The DNAA boxes are sequence motif, a specific pattern of nucleotides, which is recognized by DNA replication machinery and situated near DNA replication origin site. The idea of golden bug taken from Edgar Allan Poe’s short-story ‘The Golden-Bug’ (2), where the protagonist had to solve a cryptic message, which is written in this image on the body of the golden-bug sitting on the front, half-buried DNAA box. In this image, the protagonists are two bioinformatician, and cryptic message written on the body of gold
bug is an analogy of hidden pattern in DNA sequence. The gold bug is sitting on the DNAA box indicates that these bioinformatician has to find where DNAA box is situated by demystifying this hidden pattern.
This is exactly how bioinformatician works. They aim to break cryptic code of life, understand it and try to answer those elusive questions, such as understanding the pattern of DNAA box sequence which will help them to find origin of replication.
References:
1) Bioinformatics Algorithm I (2013-14), coursera.org,https://class.coursera.org/bioinformatics-001
2) Edgar Allan Poe (1891). The Gold Bug. G. Routledge & Sons, Limited.
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