Genome: Word that comes from combining gene and chromosome.Each cell contains a copy of the genome. Using sophisticated technologies, scientists are capable of peering into the cells of living beings. For instance, with just a few drops of blood, they can read the information encoded in cells to unveil the hidden secrets of DNA. Genes, which are tiny pieces of DNA, account for the specific traits of each individual, including eye colour, shape of the face or even the risk of developing certain genetic diseases, such as cystic fibrosis. The full set of genes – ranging from 20,000 to 25,000 in each cell according to the latest estimates – is part of the human genome.
The genome: Life’s assembly instructions
The genome is often compared to an instruction manual that contains the specific traits of individuals and their body’s operating mode. The book is divided into 23 chapters for the 23 pairs of chromosomes we inherit from our biological parents.
The genome of all living organisms, with the exception of certain viruses, is written in an alphabet of four letters that make up DNA. These letters spell words that form sentences, which correspond to genes.
In other words, the nucleus of each human cell contains 20,000 to 25,000 sentences and over 6 billion letters (3 billion pairs of bases A-T and C-G)!
Each cell reads the sentences (or genes) pertaining to it. A skin cell, for example, will consult information on skin colour and texture, but not instructions dealing with eyes or hair.
Genomics: Unlocking the secrets of the genome
While genetic researchers focus on the study of specific genes, genomic researchers work on deciphering an organism’s entire genetic makeup – in other words, its genome.
They analyze genes, but also the sections of DNA between the genes, about which there is very little known. It’s almost like trying to make sense of words that are not combined into sentences.
In summary, genomics is the scientific discipline that studies how the entire genome of a human being, animal, plant or microbe functions in order to better understand and use certain properties of its DNA in different areas.
The human genome unveiled
In 2003, after 15 years of work, genomic researchers succeeded at reading the 6 billion letters of the human genome.
We now know a great deal about the words and sentences contained in each cell of the human body, but a lot of work is still needed to understand the meaning of the text, the assembly instructions and the operating mode.
Powerful computers to read DNA
To read and analyze the billions of letters and thousands of genes that make up the genome and compare differences among individuals and species requires the use of super powerful computers, software and algorithms (complex mathematical formulas).
The discipline that focuses on interpreting the massive amount of data generated by genomics is called bioinformatics.
The power of genomics at work
In human health, genomics is used to:
- identify genetic mutations and thus predict the risk of developing certain diseases, such as breast or prostate cancer;
- tailor treatments to an individual’s genome (referred to as personalized medicine);
- screen for serious diseases in fetuses before they are born;
- thwart bacteria and viruses by better understanding their genome.
In agrifood, genomics is used to:
- make plants more resistant to diseases and pests;
- help plants adapt to climate change;
- identify and treat diseases in animals more quickly;
- rapidly identify bacteria that can contaminate food.
In forestry, genomics is used to:
- quickly identify the trees most capable of adapting to changing climatic conditions in a given region;
- make trees more resistant to certain diseases;
- combat pests, such as the spruce budworm, in an eco-responsible manner;
- rapidly detect harmful microscopic fungi.
In the environment, genomics is used to:
- find the best “pollutant-eating” microorganisms to naturally decontaminate soils;
- quickly detect invisible toxin-producing microorganisms in drinking water;
- rapidly determine the impact of toxins on living beings, while limiting the use of laboratory animals;
- use the properties of certain bacteria to clean wastewater;
- make bees more resistant to the diseases threatening their species.