Genomics
Every organism has a genome. Genome is a term used to describe all of the genes and genetic material that predict the nature of an organism. Every cell of a specific organism has the same copy of its genome.
Genomics is the study of an organism's genome. It includes an examination of the following topics:
Genomics also includes the search for genes that cause disease.
When scientists try to determine the order of nucleotides in a strand of DNA, it is called sequencing.
The genome consists of one or more long strands of deoxyribonucleic acid – commonly known as DNA. The DNA, in turn, is composed of a string of molecules called nucleotides. There are four types of nucleotides: adenine (A), guanine (G), cytosine (C), and thymine (T). Like in a series of letters that make up a word (e.g. c-a-t = cat), certain combinations or sequences of nucleotides, when interpreted by the cell, have functional meaning. Such sequences – sequences that have meaning – are called genes. Genes carry out their functional meaning through the production of proteins.
The study of genes first began in the mid-1800s when a monk named Gregor Mendel discovered that he could manipulate the physical characteristics of pea plants from generation to generation. As time passed, the hereditary units described by Mendel were later named genes. Eventually, other discoveries were made including the genome, chromosomes, DNA, and nucleotides.
By the 1970s, techniques used to sequence DNA were becoming more advanced and in 1977 a virus became the first organism to have its entire genome sequenced. Genetic laboratory techniques continued to improve and by the early 1980s, discussion of sequencing the human genome had begun.
The initial sequencing efforts began in the mid-1980s. Two significant factors during this time accelerated the human genome sequencing. The first was a race between two groups (Celera Genomics and a public multinational research group) to be the first to sequence the entire human genome. The other significant factor was an improvement in the sequencing technology. New automated sequencing devices reached the market in the 1990s, as did DNA microarray technology (see "How is a Genome Sequenced" below).
In order to determine an unknown DNA sequence, scientists can either cut or copy the DNA. Cutting and copying can be used in combination or alone, depending on the technique.
Scientists' ability to control which nucleotide appears beside a given cut, or the end of a given copy, is the key to sequencing. This means the identity of the nucleotide at the end of the cut or copied DNA piece is known.
Each nucleotide is then "lined-up" using lab techniques that separate the DNA pieces. Once the pieces are lined up, the sequence can be read.
Sequence information is recorded as a long string of the same four letters representing the combination of nucleotides in a DNA strand. Certain segments of the nucleotide sequence make up a gene. However, finding a particular gene from a long string of nucleotides can be difficult. Additionally, the function of that gene may be unknown. Two new areas of research, intimately related to genomics address these issues:
The Human Genome Project was an international effort to sequence the human genome and gather information on human genes. When scientists try to determine the order of nucleotides in a strand of DNA, it is called sequencing. The first step of the project was to sequence the entire human genome. This was completed in 2000.
Since there are billions of nucleotides in the human genome (and therefore long DNA strands), the sequencing was done in small chunks. The next tasks included assembling the sequence pieces in the correct order as they would appear in an uncut strand of human DNA, and determining the location of genes within the strand.
Canada contributed to the human genome project from 1992 to 1997 through a program called the Canadian Genome Analysis and Technology Program. This program was replaced in 2000 by Genome Canada, which continues to bolster Canadian genomics research. Currently, there are five government-sponsored centres of genomics research distributed across the country. Research topics under study within these centres include cancer, forestry, agriculture, global heath, ethical and social issues, genetic causes of disease and DNA sequencing.
Many other organizations, both private and public, are also contributing to genomics research.
There are many potential applications for genomics research. These applications are not limited to health care and could impact farming, forensics, archaeology, and the environment. Nearly all of the products of biotechnology will be or have been influenced by research in genomics. Focusing on human health care, some of the potential applications include the following:
Please visit the environment, agriculture and other product sections for more applications directly influenced by genomic research.
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