Largest animal genome (assembled)

The largest animal genome (i.e., total amount of DNA in the nucleus of a cell) to have been sequenced and assembled is that of the South American lungfish (Lepidosiren paradoxa): approximately 91 billion base pairs (Gbp, or gigabase pairs) of its genetic material have been reconstructed according to a study in Nature published on 14 August 2024. This freshwater fish is endemic to slow-moving rivers and wetlands in northern South America, including the Amazon and Paraná river basins. For context, the human genome comprises “only” 3.2 Gbp; 18 of the South American lungfish’s 19 chromosomes contain more bases than within the entire human genome.

The research was a collaboration between the University of Würzburg, University of Konstanz, Leibniz Institute for Zoo & Wildlife Research, Max-Planck Institute of Molecular Cell Biology and Genetics, Universität Hamburg, Leibniz Institute for the Analysis of Biodiversity Change (all Germany), Uppsala University (Sweden), University of Tuscia (Italy), University of Bordeaux (France), University of Vienna (Austria), Texas State University, Louisiana State University, University of California, Irvine (all USA), Universidade Federal do Pará (Brazil), led by Würzburg biochemist Professor Manfred Schartl and Konstanz biologist Professor Axel Meyer.

This giant genome surpassed the previous 43 Gbp sequenced and assembled for the related Australian lungfish (Neoceratodus forsteri) of Queensland, Australia, as discussed in Nature on 18 January 2021.

The largest-known genome overall for an animal using best-practice methods (though not assembled) is 129.9 Gbp for yet another lungfish: the marbled lungfish (Protopterus aethiopicus) of Africa as documented in the Journal of Experimental Zoology by Dr Keith Thomson in June 1972. This fish boasts over 40 times more genetic material than that found in the nuclei of human cells (3.2 Gbp).

The largest genome for a plant – as well as for any organism overall based on flow-cytometry analysis – is 160.45 Gbp for the Tmesipteris oblanceolata fork fern. It is native to tropical forests in the French overseas territory of New Caledonia and other nearby islands, such as Vanuatu, in the south-west Pacific Ocean. The findings were published in the journal iScience on 31 May 2024. Unravelled, this fern's DNA would stretch out more than 100 m (328 ft), which is taller than the Statue of Liberty or Big Ben's Elizabeth Tower.

While the largest plant genome to have been sequenced and assembled is that of the European mistletoe (Viscum album), for which 94 Gbp has so far been curated into its original configuration by scientists at the Darwin Tree of Life project, according to research published in December 2022.