The South American lungfish (Lepidosiren paradoxa) has the largest known animal genome, with up to 91 billion base pairs, 30 times larger than the human genome, according to new study published in Nature. It also has more than double the size of the previously known largest animal genome, the Australian lungfish.
Lungfish are considered "living fossils" and are believed to be the closest relatives of the first four-legged species, ancestors of all vertebrates, which likely grew limbs and crawled onto land around 370 million years ago.
"18 of the 19 chromosomes of the South American lungfish are each individually larger than the entire human genome with its almost 3 billion bases," Axel Meyer, one of the study's authors, said.
This genome expansion in the species is driven by the proliferation of transposable elements or "jumping genes," which make up over 90% of the genome, suggesting a weakening of mechanisms that suppress genome repetition.
The study of the lungfish genome offers valuable insights into the mechanisms controlling genome size, the complexity and significance of genome size changes, and the origin of life and the evolution of vertebrates, including the transition from water to land animals.
Advances in DNA sequencing and bioinformatics enable sequencing and assembling macro-scale genomes, including the chromosomes of lungfish.
Sources: DW, LTN, Live Science, Newsweek, Gazeta, Nature, Folha, Olhar Digital, Terra, New Scientist, Canaltech, Welt, Super, BioBioChile, ADN Radio, EVZ, Evrim Ağacı, Naftemporiki
This article was written in collaboration with Generative AI news company Alchemiq.
