Reference genome of the Saimaa ringed seal released

Scientists at the University of Eastern Finland and the University of Oulu have unveiled the first chromosome-level reference genome for the Saimaa ringed seal, a critically-endangered seal species that resides exclusively in Lake Saimaa, Finland. By sequencing every chromosome in the seal's complete genome and mapping them virtually, researchers have gained unprecedented insights into the species' genetic makeup and adaptation to its freshwater habitat.

The genome, which is 2.35 billion base pairs long and composed of 17 chromosomes, contains approximately 21,800 genes - slightly more than the human genome. Comparative genomic studies have highlighted several genetic differences that may be linked to the seal's adaptation to life in a freshwater environment, particularly in genes related to ion transport, kidney function, and olfactory receptors.

Importantly, the genome was assembled from a living Saimaa ringed seal named Tuukka, whose genetic material was collected in 2023. This approach ensures the genome accurately reflects the seal's unique genetic makeup, providing valuable resources for current research and future conservation efforts. The genome's utility extends beyond basic scientific understanding, offering a high-quality reference for studying genetic diversity, inbreeding, population history, and inherited defects within the small and fragmented seal population.

The newly published reference genome will bolster ongoing conservation initiatives, such as tissue biobanking and genomic monitoring, and it will play a pivotal role in the LIFE project, a new initiative aimed at increasing the Saimaa ringed seal population to 700 individuals by 2032. Additionally, the genome will contribute to international efforts in generating high-quality reference genomes for Earth's biodiversity.