The power is in the sequence!
To decode DNA, it’s essential to read the order of the letters that compose it. This is called sequencing. This sequence of letters is precisely what varies from one species to another and from one individual to another.
Let’s play!
Mix the four letters of DNA to create the 24 possible combinations. Each sequence produced reveals a new living organism.
Learn more about the genomic characteristics of selected living organisms :
There are two types of melanin: eumelanin, which ranges in color from brown to black, and pheomelanin, which ranges in color from red to pink. Redheads have a mutation in the MC1R gene that causes them to produce more pheomelanin than eumelanin, so their hair is red. This is a recessive gene. For a child to have red hair, both biological parents must each pass on a copy of the recessive gene. The MC1R gene is located on chromosome 16.
Darker-skinned people produce more melanin than fair-skinned people. This is genetically determined. The role of melanin is to protect our DNA from sun damage (UV rays). High levels of melanin help protect the DNA of skin cells from molecular damage caused by UV radiation.
Alpha and beta particles, as well as X-rays, can modify a DNA molecule in one of three ways, causing:
- A change in the chemical structure of the bases
- A breakdown of the sugar-phosphate backbone
- A rupture of the hydrogen bonds connecting the base pairs
People with lactose intolerance produce little or no lactase, the enzyme capable of digesting lactose. All individuals produce lactase at birth, but some lose this ability as they age. It is the LCT gene that determines whether an individual will produce lactase for life or not. The allele that codes for lactase production is dominant.
Source: Full article: Lactose intolerance: diagnosis, genetic, and clinical factors
Vitiligo is a loss of melanocytes in the skin, resulting in depigmentation of skin areas of various sizes. The cause remains unknown, but genetic and autoimmune factors are likely.
Source: Vitiligo – Dermatologic Disorders – Merck Manual Professional Edition
Hair can have different textures and shapes. Different genes, including the EDAR gene, are involved in the variations between hair types. It’s also thought that curly hair may have played a role in evolution, as it provides more protection from the sun than straight hair!
‘’Gène EDAR mis en lumière : (…), hair shape was scored on a simple four-point scale (straight, wavy, curly or frizzy) and found to be associated with polymorphic variation in known curl-associated genes (EDAR, trichohyalin) and a yet non-described gene, protease serine S1 family member 53a (PRSS53).‘’
At the end of chromosomes are telomeres. These repetitive DNA sequences contain no genes: they are there to preserve the integrity of our genetic heritage. But every time a cell recopies its DNA before dividing, it loses a little piece of telomere. They are the first to be damaged when we are subjected to UV rays, radiation and so on. As our lives progress, our telomeres shorten. Telomeres are shorter in the elderly, making them more vulnerable to certain diseases.
Additional information: Are Telomeres the Key to Aging and Cancer
Monozygotic twins initially share the same DNA. However, the mutations that will occur during their lives, as well as epigenetic modifications (changes in DNA due to the environment), are not necessarily the same for both individuals. The DNA of two identical twins therefore differs more and more over the course of their lives.
Monozygotic twins are very useful for scientific research. By comparing the tastes and habits of two people sharing the same genetic code, we can find out what is and isn’t determined by DNA.
The DNA of an astronaut who spent a year in space was compared with that of his twin brother who remained on earth. This made it possible, for example, to determine the changes in DNA caused by prolonged space travel.
Source : Twins can become ‘unidentical’—and more fascinating twin facts
Albinism is a rare hereditary disease characterized by little or no production of melanin, a skin pigment. Skin, hair and eyes are affected, or sometimes only the eyes.
Albinism is a genetic disease that exists in several forms and is caused by different genes. There are 19 known genes involved in the different forms of albinism
Source : Albinism – Skin Disorders – Merck Manual Consumer Version
Latin name: Pan troglodytes
Humans share 98.8% of their DNA with chimpanzees and bonobos. We are so similar because we share a relatively recent common ancestor. Half-human, half-chimpanzee – Québec Science Comparing Chimp, Bonobo and Human DNA | AMNH
Statistics (La Presse, Smithsonian)
- 3.5 billion years old – Age of the oldest known bacteria, found in Australia
- 500 million years old – Last common ancestor between fish and humans
- Between 5 and 7 million years ago – Last common ancestor of humans and chimpanzees
- 430,000 years ago – Appearance of Neanderthal man
- 40,000 years ago – Disappearance of Neanderthal man
- Between 350,000 and 260,000 years ago – Appearance of Homo sapiens
Additional information:The Smithsonian’s Human Origins Program | The Smithsonian Institution’s Human Origins Program
Latin name: Castor canadensis
In 2017, for Canada’s 150th anniversary, the complete genome of the Canadian Beaver was sequenced.
Beavers are highly resistant to cancer, thanks to several of their genes. These genes are therefore being studied to better understand cancer defense mechanisms.
Source : Homegrown research team sequences genome of iconic Canadian animal – the beaver – GenomeCanada
Latin name: Rangifer tarandus caribou
There is only one species of caribou in the world. In Canada, there are currently four subspecies of caribou, only one of which is found in Québec: the woodland caribou.There are three ecotypes of caribou in Québec. Woodland caribou, mountain caribou and migratory caribou. Ecotypes are subspecies that have adapted to different environments.
Source: Caribou in Canada – Canada.ca
Funded project : A DNA chip to monitor and protect caribou populations | GénomeQuébec inc.
Latin name: Delphinapterus leucas
Génome Québec and Espace pour la vie have launched a citizen science project to better understand the biodiversity of the St. Lawrence: Code Beluga!
To participate code Béluga | GénomeQuébec inc.
Belugas are cetaceans, just like whales and dolphins. Please note that belugas are not dolphins, but they do belong to the micro-order odontocetes (toothed cetaceans), as do dolphins, sperm whales, killer whales and so on.
Source: Beluga whale – Wikipedia
Latin name: Acipenser fulvescens
There are two species of sturgeon in Québec: black and lake.The lake sturgeon was less common in the 70s, as it was fished extensively. Today, there are more individuals. It’s a species with a status: likely to be designated as threatened or vulnerable.
Sources (In French only)
Esturgeon jaune | Gouvernement du Québec
Segment | La Semaine Verte | ICI Radio-Canada.ca
Additional information: Aquatic Species at Risk, Lake Sturgeon (Acipenser fulvescens)
Latin name: Dreissena polymorpha
It’s a freshwater mussel native to the Caspian Sea. It is an invasive alien species that can be detected using environmental DNA. Invasive alien species are species that invade an environment that is not originally theirs. As these species often have no predators, they multiply rapidly and compete with native species for resources.
Source: Zebra Mussel
Latin name: Archilochus colubris
It’s the only bird that can fly backwards. It can also fly while treading water. Its wings can beat up to 100 times per second, and it moves at an average speed of 56 km/h!
Source: The Science of Hummingbirds
Latin name: Apis
Bees are essential for pollination. Without bees, flowers would not be pollinated. There would be no fertilization, and therefore no fruit. Learn more about a Génome Québec funded project for the breeding and genomic selection of honeybees
Funded project: ApiOmic, honeybee breeding and selection using genomics | GénomeQuébec inc.
Latin name : Chrysaora pacifica
We know the adult version of jellyfish, but few people know that they have a juvenile stage called a polyp.
Some jellyfish (Turritopsis dohrnii) are said to be immortal. They are so called because they can return to the polyp stage, an embryonic stage in their development.
Source: https://www.genomebc.ca/20-cool-genomics-facts/fact-19-immortal-jellyfish
Latin name: Abies fraseri
Genomics makes it possible to monitor and protect the health of our forests. For example, it enables us to track the progress of invasive exotic species, such as certain insect pests, and act before they can do too much damage.
Funded project: Genomics protecting our forests from pests | GénomeQuébec inc.
Latin name:Taraxacum officinale
Did you know that when a dandelion turns white, the filaments you see are called pappus? These are attached to the plant’s seeds. When it’s windy, or the flowers are blown, the pappus allow the seeds to float in the wind and be spread far and wide!
Sources: Pappus (botany) – Wikipedia, https://torontobotanicalgarden.ca/blog/word-of-the-week/botanical-nerd-word-pappus/
Latin name: Pisum sativum
It was these plants that Mendel used in his experiments to understand the foundations of heredity.
Additional information: Reproduction and heredity | GénomeQuébec inc.
Latin name: Solanum lycopersicum
Tomato crops are susceptible to various diseases and pathogens that can devastate them. This is particularly true of tomato bacterial canker, caused by the bacterium Clavibacter michiganensis.
Génome Québec is currently funding a research project focusing on the genome of this bacterium to understand its spread. The project also seeks to better understand and improve a biological control tool for this disease. This tool uses another bacterium, Bacillus spp.
Funded project: Understanding the interplay between Clavibacter michiganensis, tomato, and a biological control agent | GénomeQuébec inc.
Covid-19 (SARS-CoV-2)
Viruses are not cells but possess genetic material in the form of DNA or RNA. To replicate and propagate, they must exploit the mechanisms and resources of the cell they invade. This is called the host cell. In the case of DNA viruses, the viral genome enters the nucleus and fuses with the host cell’s DNA. The virus then takes control of the cell’s machinery to produce viral proteins.
RNA viruses, on the other hand, directly exploit the ribosomes of infected cells to produce viral proteins.
Additional information: DNA: The Code of Life! | GénomeQuébec inc.
Bacteria are single-celled living organisms with DNA. Some bacteria are used to produce useful substances such as insulin.
Additional information: https://www.genomebc.ca/20-cool-genomics-facts/fact-15-helpful-microorganisms
Latin name: Cantharellus cibarius
Fungi are made up of a visible part, the sporophore, and a subterranean part, the mycelium. The latter is much larger and made up of filaments called hyphae. Sometimes, hyphal cells are not separated from each other and have several nuclei. The part of the mushroom we usually see and sometimes eat is the sporophore. It is used for the production and distribution of spores, in other words, for reproduction.
Source: Hypha – Wikipedia
Additional information: Genomics-enhanced biovigilance to improve crop disease management | GénomeQuébec inc.
