St Petersburg University scientists sequence the genome of the Baikal seal
As part of an international team, St Petersburg University biologists have for the first time described the genome of the Baikal seal or nerpa, the only mammal inhabiting Lake Baikal.
The Baikal seal is one of the three types of seals living in fresh water. It is the only mammal inhabiting Lake Baikal, the deepest lake on the planet. In the late 20th century, the number of seals was greatly reduced (up to 100 thousand animal units) due to a distemper outbreak, but in recent years it has been gradually recovering. According to our scientists, sequencing of the genome of this animal in future will ensure a gradual increase in the population, since the genes store all the information about the history of individual species and individuals. This approach will help take into account the conditions in which animals survive best.
The research findings are published in Genes, one of the best scientific journals in genetics.
’This idea emerged more than ten years ago as part of the Genome 10K 100k international project. It was the initiative of Stephen O’Brian, the then head of the Theodosius Dobzhansky Centre for Genomic Bioinformatics at St Petersburg University. The project was aimed at sequencing the genomes of 100,000 living organisms, including the Baikal seal,’ said Alla Lapidus, Professor in the Department of Cytology and Histology at St Petersburg University, Director of the Centre for Algorithmic Biotechnology at St Petersburg University.
The project was delayed due to lack of resources and the complexity of the Baikal seal’s DNA. The first version developed by the scientists turned out to be just a set of separate fragments, which were extremely difficult to arrange due to numerous repeating sections. This problem was solved using the new Hi-C method. That enabled the scientists of St Petersburg University to achieve their goal and sequence the genome of the Baikal seal.
’The Hi-C method enables you to identify DNA sequences that are physically close to each other in a cell. With this information, we can organise the fragments we have by assembling them into complete chromosomes,’ explained Mikhail Rayko, Senior Research Associate in the Centre for Algorithmic Biotechnology at St Petersburg University.
Thanks to the sequencing of the Baikal seal genome, the scientists of our University were able to understand its origin and relationships, as well as the genetic diversity of the population. It is a key characteristic for species of conservation concern to which the Baikal seal belongs. Thus, the absence of variability, that is, genetic diversity, can threaten the very existence of species.
St Petersburg University, the oldest university in Russia, was founded on 28 January (8 February) 1724. This is the day when Peter the Great issued a decree establishing the University and the Russian Academy of Sciences. Today, St Petersburg University is an internationally recognised centre for education, research and culture. In 2024, St Petersburg University will celebrate its 300th anniversary.
The plan of events during the celebration of the anniversary of the University was approved at the meeting of the Organising Committee for the celebration of St Petersburg University’s 300th anniversary. The meeting was chaired by Dmitry Chernyshenko, Prime Minister of the Russian Federation. Among the events are: the naming of a minor planet in honour of St Petersburg University; the issuance of bank cards with a special design; the creation of postage stamps dedicated to the history of the oldest university in Russia; and the branding of the aircraft of the Rossiya Airlines to name just a few. The University has launched a website dedicated to the upcoming holiday. The website contains information about outstanding University staff, students, and alumni; scientific achievements; and details of preparations for the anniversary.
Another important issue that scientists will be able to answer in future thanks to this study is the origin of the Baikal seal. Currently, there is a theory that about three million years ago, this seal migrated from the coasts of the Arctic Ocean to the south along the rivers. Thus, it ended up in Lake Baikal, which was later separated from salty reservoirs.
In addition, this study will enable scientists to compare the genome of the Baikal seal with other representatives of the northern fauna and other species of seals living in fresh water, and determine at which point the populations split.