Why genome is important

Even in a familiar language it is difficult to pick out the meaning of the passage: The quick brown fox jumped over the lazy dog. The dog lay quietly dreaming of dinner.

And the genome is "written" in a far less familiar language, multiplying the difficulties involved in reading it. So sequencing the genome doesn't immediately lay open the genetic secrets of an entire species. Even with a rough draft of the human genome sequence in hand, much work remains to be done.

Scientists still have to translate those strings of letters into an understanding of how the genome works: what the various genes that make up the genome do, how different genes are related, and how the various parts of the genome are coordinated. That is, they have to figure out what those letters of the genome sequence mean. At the very least, the genome sequence will represent a valuable shortcut, helping scientists find genes much more easily and quickly.

A genome sequence does contain some clues about where genes are, even though scientists are just learning to interpret these clues. Finally, genes account for less than 25 percent of the DNA in the genome, and so knowing the entire genome sequence will help scientists study the parts of the genome outside the genes. The quick answer to this question is: in pieces. The whole genome can't be sequenced all at once because available methods of DNA sequencing can only handle short stretches of DNA at a time.

So instead, scientists must break the genome into small pieces, sequence the pieces, and then reassemble them in the proper order to arrive at the sequence of the whole genome. Much of the work involved in sequencing lies in putting together this giant biological jigsaw puzzle. There are two approaches to the task of cutting up the genome and putting it back together again. One strategy, known as the "clone-by-clone" approach, involves first breaking the genome up into relatively large chunks, called clones, about , base pairs bp long.

Scientists use genome mapping techniques discussed in further detail later to figure out where in the genome each clone belongs. Finally, they sequence the pieces and use the overlaps to reconstruct the sequence of the whole clone. The other strategy, called "whole-genome shotgun" method, involves breaking the genome up into small pieces, sequencing the pieces, and reassembling the pieces into the full genome sequence.

Each of these approaches has advantages and disadvantages. The clone-by-clone method is reliable but slow, and the mapping step can be especially time-consuming. Their foldings in space are essential to allow the cell to read all the instructions necessary for its proper functioning. In some circumstances where the structure of chromosomes is damaged, cells cannot function properly and contribute to fatal diseases such as various types of cancer or developmental disorders.

Blog Last posts. This website may use its own and third-party cookies to offer you a better experience and service in accordance with your browsing habits.

You can expand the information about our cookies policy. Click on this button if you agree: Ok Privacy policy. Genomics can identify these alterations and search for them using an ever-growing number of genetic tests, many available online. If your results suggest susceptibility to a condition, you may be able to take preemptive action to delay or even stop the disease developing.

When symptoms do develop, genomics can be instrumental in diagnosing the problem. The Human Genome Project has fueled the discovery of nearly 2, disease genes, and these are proving highly effective at providing fast and accurate analysis.

Such databases could deliver a definitive diagnosis in seconds, and even recommend targeted treatments based on the DNA of both the patient and the disease.

Indeed, genetic sequencing of cancer tumors is helping not only to identify particular cancers but also to understand what causes them and what could kill them. When it comes to treatment, genomics is driving another important element of precision medicine—pharmacogenomics. Now we know why: Our genes influence the production of crucial enzymes in the liver that metabolize medicines.

If a genetic variation stops the enzymes from working properly, the drug can build up in the body with serious side effects. Such gene variations, known as polymorphisms, are common, but genomics means we can test for them and compensate for them.

Gene variations mean that around 30 percent of people cannot fully convert a commonly used anti-clotting drug, but gene testing means alternative drugs can be taken to the same effect.