STORY: Here in the wilds of New Caledonia –
scientists have discovered a living organism with the largest genome in the world.
:: RGB KEW
“And it’s particularly exciting because it’s a plant.”
New research shows that the genome size of this forked fern species…
is estimated to be more than 50 times the size of a human genome.
:: Ilia Leitch, plant geneticist, Royal Botanic Gardens Kew
“And that breaks all previous records.” So it’s a really exciting study to really understand biology at its limits. »
Scientists have long wondered why some organisms have large genomes and others do not.
Plant geneticist Ilia Leitch, of the Royal Botanic Gardens, Kew, UK, co-authored the study published in the journal iScience.
“We were able to show that genome size can have an impact, influencing how, where and when a plant is able to grow. How well it competes with other plants in the plant community, and even the probability of its ability to develop to be resilient to climate change or its ability not to be threatened with extinction.
The specimens used in the study were collected last year on the island of Grande Terre in New Caledonia.
The fern grows mainly on the ground or on the tops of fallen tree trunks.
It belongs to a family of ferns whose evolutionary lineage separated from other ferns about 350 million years ago, about 120 million years before the appearance of dinosaurs.
“This fern actually has 416 chromosomes in each cell. Whereas the sequencing of the human genome required the assembly of DNA into 23 chromosomes.”
But a large genome is not necessarily considered beneficial.
For example, larger genomes require more resources for DNA replication, repair and transcription – a process that a cell uses to make the proteins an organism needs to function.
“Well, our most recent research actually shows that, not surprisingly, species with larger genomes are at greater risk of extinction. So understanding genome size, knowing plant genome size means that “We may be able to help identify species that are at higher risk than others.”
The African marbled lungfish has the largest known animal genome. That of the fern is almost 25% larger.
“It just highlights the fact that plants are really important to all of us, because they provide us with the food, the oxygen we breathe and the clothes we wear. So raising the profile of plants, perhaps even in a small way, just goes a long way toward helping people truly appreciate the importance and value of plants and why we need to conserve them.
yahoo
