COMPUTATIONAL GENOMICS
THE "HOW" OF SCIENCE
THE HUMAN GENOME
PROJECT
WHAT IS THE HUMAN GENOME PROJECT?
There are over 30,000 genes in your cells, each with a specific purpose. In October of 1990, The Human Genome Project was started by the National Human Genome Reseach Institute (NHGI) in an attempt to determine the DNA sequence of the entire human genome. The thirteen-year project was completed in 2003 and includes the sequence of over 3 billion chemicals that make up a persons' DNA. The valuable information that was uncovered during the project is now stored in databases where it is widely available for study in order to study, treat, cure, and prevent thousands the thousands of genetic diseases that affect humans every year [1].
The timeline above shows the complex history of the human genome project over the three years that it was conducted [1]
WHAT IS A GENOME?
DNA is a chemical compound that contains the instructions to code for the proteins necessary for critical day-to-day functions. DNA consists of two twisted strands of 4 major chemical bases, called nucleotides.
These nucleotides (adenine, cytosine, thymine, and guanine) bond together in a unique sequence in order to create the code to create proteins.
In each cell, there are about 3 billion pairs of nucleotides, which are contained in 23 chromosomes in the nucleus of each cell. The genome defines the complete set of these 3 billion pairs [2].
This diagram provides some background about the definitions of DNA, chromosomes and genomes [2].
HOW DO YOU SEQUENCE A GENOME?
There are two methods that scientists used to sequence the human genome for the project. The first method, which is called BAC gene mapping, is the relatively slow process of creating a map of the genome. In order to accomplish this, scientists cut the chromosomes into smaller pieces, normally about 150,000-200,000 genes, that are more manageable to study. Then, using computer programs, the scientists are able to reassemble the genome, kind of like a puzzle [2].
In the second technique, which is often called shotgun sequencing, the gene is randomly cut up into manageable pieces (normally about 2,000 base pairs) by forcing DNA through a pressurized syringe. Then, a computer program is able to identify where bases overlap and reconstruct the sequenced genome. This technique is way simpler and faster than BAC sequencing because it completely omits the use of bacterial cloning that is an integral part of BAC sequencing [3].
This video explains how shotgun sequencing works, which is one of the major techniques used during the human genome project [1a]
WHY IS THE HUMAN GENOME PROJECT IMPORTANT?
The wealth of information studied during the HGP is incredibly important in learning more about our genome and how different diseases affect us. For example, by learning more about variations in the patterns in our genome, scientists are able to discover how different diseases affect different people in different ways [1].
Scientists are now able to better understand how a person's genetic makeup can make them more susceptible to a disease, diagnosis genetic disorders earlier and with more accuracy, and tailor medicine so that it is unique to each person's specific genetic makeup.
This image shows that the technology developed during the human genome project was essential in developing new methods of personalized medicine [3].
This image symbolizes the fact that the human genome project helps scientists learn more about how the human body works [4].
Personalized cancer medicine is a big effort that is made possible by the technology and information gathered during the human genome project [5].