Scientists Decode Largest Animal Genome, 30 Times Bigger Than Human's
An international team of researchers, led by biochemist Manfred Schartl from Würzburg and biologist Axel Meyer from Konstanz, has successfully sequenced the genome of the South American lungfish (Lepidosiren paradoxa), revealing it to be the largest animal genome ever sequenced. With over 90 billion base pairs, the lungfish genome is approximately 30 times larger than the human genome and more than twice the size of the previously largest known genome, that of the Australian lungfish. This accomplishment was achieved using advanced long-read sequencing technology, which allows for the analysis of longer DNA sequences and helps overcome challenges posed by repetitive DNA sequences.
The study also sequenced the genome of the African lungfish, contributing to a comprehensive genetic resource of all six lungfish species globally. Researchers identified that the rapid expansion of the lungfish genome is primarily driven by autonomous transposons—DNA sequences that can replicate and move within the genome, causing it to grow. This expansion rate is the fastest recorded, with the genome increasing in size by an amount equivalent to the entire human genome every ten million years. The study found no correlation between the extensive genome size and genome instability, suggesting that the lungfish genome maintains a conservative gene arrangement despite its size.
These findings offer significant insights into the evolutionary history of vertebrates, particularly how fish ancestors adapted to life on land around 380 to 360 million years ago. The research provides a deeper understanding of the genetic basis of unique traits in lungfish and their evolutionary significance, potentially advancing the fields of evolutionary biology and genetics. The sequencing of the lungfish genome marks a pivotal step in exploring the genetic foundations of vertebrate evolution and opens new avenues for further scientific investigation.
