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- Presented a gene plan: DNA analysis will allow to revive endangered Russian muskrats
Presented a gene plan: DNA analysis will allow to revive endangered Russian muskrats
An international team of researchers has for the first time decoded the high-quality genome of the Russian muskrat. The analysis showed a critically low genetic diversity of this endemic species, which lives mainly in Russia. Studying its genome and demographic history will make it possible to develop methods for breeding animals in artificial conditions. According to experts, these animals deserve to become one of the national symbols of our country. Read more about how scientists plan to revive the "water moles" in the Izvestia article.
Why is the Russian muskrat dying out
For the first time, Russian and Uzbek scientists have deciphered the high—quality genome of the Russian muskrat, a rare waterfowl that is now on the verge of extinction. The study allowed us to look into the past of the species and reconstruct its demographic history. This may contribute to the invention of animal regeneration methods.
The scientific work was attended by employees of the European University in St. Petersburg (EUSP), Lomonosov Moscow State University, the Institute of the Center for Advanced Technologies of the Academy of Sciences of the Republic of Uzbekistan and a number of Russian research organizations.
— Russian muskrats are of interest because they are a relict species that is about 35-40 million years old. At the same time, they have hardly changed in the course of evolution. Therefore, one of the goals of the study was to understand why these animals, contemporaries of mammoths and woolly rhinoceroses, who successfully survived the Ice Age, are currently under threat of extinction," Artyom Nedoluzhko, scientific director of the EUSP Paleogenomics laboratory, told Izvestia.
Russian muskrats are also known as water moles or muskrats. They received the first nickname for their ability to swim well and dig holes underwater, and the second for the valuable secret secreted by their glands.
These animals are endemic. They live mainly in the south of the European part of Russia. In the 17th and 19th centuries, muskrats were exterminated because of their valuable fur and musk, a strong–smelling substance that was used to enhance the smell of perfumes. In the 20th century, the destruction of their habitat due to deforestation, dam construction and drainage of reservoirs contributed to the reduction in the number of animals.
According to the researchers, the analysis showed that the genetic diversity of the Russian muskrat is about 200 SNP/Mb (single nucleotide substitutions per megabase). This value reflects the frequency of mutations in DNA on a segment of the genome of 1 million base pairs. This indicator is one of the lowest among mammals, which makes muskrats one of the most vulnerable groups of animals, whose survival depends entirely on intensive conservation measures.
How to prevent population decline
Scientists have found that the diversity of the species has been declining for hundreds of thousands of years. This came as a surprise, since it was previously believed that the main reason for the decrease in the number of animals was related to human influence.
"Our results show a general trend towards a long—standing and steady decline in population size from a peak several hundred thousand years ago. According to the data obtained, the effective number of Russian muskrats was the highest 400-500 thousand years ago, and then began to decline. This process has been most clearly expressed over the past 100,000 years. The analysis revealed that the strongest population decline occurred in the Late Pleistocene — Early Holocene (14.7–11 thousand years ago)," explained Anna Bannikova, a leading researcher at the Department of Vertebrate Zoology at the Moscow State University Faculty of Biology.
The study demonstrated that the main factors that led to the population decline were anthropogenic in nature. These include a decrease in the area of forests, which led to shallowing and drying of rivers and lakes, and a decrease in the groundwater level in wetlands.
Natural evolutionary processes should not be discounted either. For example, as a result of warming after the ice Age, the number of individuals could decrease due to changes in the regime of reservoirs. In particular, due to the freezing to the bottom of small rivers and lakes, high spring floods and severe summer droughts, which disrupted the usual water levels.
According to Anna Bannikova, in addition to measures to revive muskrats in the wild, efforts should be directed towards creating a stable population of the species in artificial conditions in order to avoid their loss in the event of extinction in their natural habitat. To do this, it is necessary to learn how to breed animals in captivity, which has not yet been possible.
— A low genetic diversity level always threatens the population with extinction. The accumulated paleogenetic data is very eloquent evidence of this," paleontologist and science popularizer Andrey Zhuravlev told Izvestia.
The scientist added that muskrats are very vulnerable animals. They do not tolerate stress well and place high demands on places. Therefore, effective State measures are needed to effectively manage specially protected areas. This will prevent the transition of many species in Russia from the "endangered" category to the "endangered" category.
— If it is difficult to influence the long-term evolutionary process, then it is not easy, but realistic, to restore what was lost through human fault. Since the 1970s, steps have been taken to achieve this. The species is listed in the Red Book of the Russian Federation, a ban on trapping animals has been introduced, reserves have been organized and eco-education is carried out. But reducing anthropogenic pressure alone may not be enough to save the species," explained Valeria Omelko, senior researcher at the Laboratory of Theriology at the Federal Research Center for Biodiversity of the Far Eastern Branch of the Russian Academy of Sciences.
According to her, targeted research will help identify populations with high genetic diversity. This will reduce the risks of relocating animals to new habitats. One of the problems is related to the fragmentation of animal habitats, so it is necessary to restore links between disparate populations.
The Russian muskrat, the expert noted, has already been chosen as its symbol by some nature reserves and environmental organizations, including the Zoological Museum of Moscow State University. The animals have every chance of becoming a national symbol, the scientist believes.
— Research shows that the situation is alarming. Low diversity by itself does not kill instantly, but makes the species "fragile". This reduces its ability to adapt to new conditions and increases the risk of closely related interbreeding. Taking into account the fact that there are less than 8-10 thousand individuals left in nature, the species is objectively endangered," commented Yaroslav Popov, paleontologist, popularizer of science and consultant to the 3D Dinopedia project.
He added that high-quality genetic analysis will make it possible to better monitor the health of populations. The knowledge gained will help to create a standardized monitoring system and control the genetic diversity of the species in different regions. However, simple prohibitive measures are not enough to preserve the Russian muskrat, the expert is sure. Active intervention is needed to restore habitats.
According to the expert, the muskrat is a unique relic, an ancient branch of evolution that has miraculously survived to the present day. Since these animals live only in clean floodplain reservoirs, they are an ideal indicator of environmental health. Finally, the muskrat is simply charming — a mix of a mole, an otter and a slit-tooth. Therefore, this animal deserves to become both a national symbol and an emblem of the movement against environmental problems.
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