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The achievements of human beings in the field of life sciences today are inseparable from the contributions made by laboratory animals in the front line of scientific research. When it comes to laboratory animals, the first thing that may come to mind is mice in biomedical research, rabbits, or orangutans in behavioral and cognitive experiments. Today, our protagonist is a fish that is not well-known, but is completely discovered and proposed by Chinese scholars as an experimental animal - gobiocypris rarus.
Rare salamander specimens
Internationally used fish experimental animal - zebrafish
At present, the experimental fish commonly used in the world is actually another fish - Danio rerio ..
Compared with other experimental animals, although fish has been widely used in experimental research later, some of its advantages are irreplaceable.
Because it is very similar to humans, monkeys and orangutans are common experimental animals, but they are also more likely to cause experimental ethics problems; the well-known experimental animal mice are excellent experimental materials in the fields of physiology and medicine, but their embryos develop in the womb, which is difficult to observe and manipulate; and the other vertebrate Xenopus, which is often used in scientific experiments, although it has the advantages of embryonic in vitro development and a large individual, has a pivotal position in developmental biology, but its life cycle is long. It is difficult to study genetics, and at the same time, it is heterologous tetraploid, and most genes have four copies, making it difficult to perform genetic mutation experiments.
(Image from the Internet)
Xenopus takes 1-2 years to reach sexual maturity, with an average lifespan of 5-15 years, some can live to 20 years (image from the Internet)
The zebrafish, at the same time, has the characteristics of strong reproductive ability, in vitro spawning, transparent and easy to observe embryos, and has quickly become the "new favorite" of the experimental animal kingdom. More importantly, zebrafish and human genetic similarity of up to 87%, for human developmental biology and molecular developmental genetics has made outstanding contributions, not only that, zebrafish is also widely used in toxicological tests, with high sensitivity, low cost, strong repeatability and other advantages, while facilitating further study of pollutant pathogenesis.
There is no distinction between high and low life, but compared with mammals, fish as laboratory animals are more in line with the first "Replacement" principle of the "3Rs" principle of laboratory animal ethics, that is, the use of low-grade animals instead of high-grade principles (the 3R principle was first proposed in 1959, that is, Deployment-substitution, Reduction-reduction, refinement-optimization).
Zebrafish wild school of fish (image from the internet)
Adult zebrafish usually do not exceed 4 cm in length and have a lifespan of about 2-3 years
In addition to the world's common zebrafish, China also has rare bass carp
In fact, as early as the 1990s, the Institute of Hydrobiology of the Chinese Academy of Sciences has begun to conduct experimental animal research on rare catfish carp, and actively promote its application in various fields.
Rare catfish is a small fish unique to China, with short life cycle, superior reproductive performance, large eggs and transparent advantages, is a good experimental material for basic biology, pathology, genetics, researchers have completed the whole gene sequencing work, the closed group of genetic resources can be used as a seed source for ecotoxicology testing.
Not only that, because it is very sensitive to viruses and heavy metals, rare catfish is a famous "poison fish" in the field of environmental monitoring in China, and has promulgated national standards for acute toxicity tests of rare catfish carp, and other relevant standards are also being formulated.
What are the advantages of rare bass carp compared to zebrafish? As a warm water fish, rare salamanders have higher adaptability to feeding environments such as temperature than tropical fish such as zebrafish.
With the deepening of the standardization of laboratory animals and the development of gene sequencing, rare catfish will be more widely used in related research and verification.
Rare salamander commonly known as Golden White Lady, a genus of salami carps in the family Cyprinidae (Photo: Marine fish swimming in the river)
Q&A about rare salamander
During the reception and explanation of the Museum of Aquatic Biology, many visitors asked the following two questions:
Q1: Since it is "rare", can it be used as an experimental animal?
A: Rare salamander is not a widespread species, the wild population is relatively rare, is a national second-level protected animal, but after standardized breeding in the laboratory, it can still be rationally developed and utilized as a model organism. Far from contradictory, the two are mutually beneficial, which is also in line with the general principles of model organisms in the world.
Q2: How is the rare salamander known as the "poison fish" tested for poison?
A: Researchers expose the embryos, juveniles or adults of rare catfish to the chemical to be measured, and quantitatively evaluate the toxicity of the chemical by observing growth and development indicators such as teratogenicity, mortality rate or enzyme activity in body tissues. In addition, with the increasing maturity of related technologies, researchers are expected to modify the genes of rare salamanders to enable them to qualitatively perceive pollution in water bodies in more intuitive ways such as discoloration.
Laboratory animals: the soul returns to nature, and the merit remains in the heavens and the earth
Laboratory animals are used in experimental research, dating back to the end of the nineteenth century. Over the past hundred years, laboratory animals have been applied to life science research and promoted the progress and development of today's biological, medical, agricultural and other fields.
It is estimated that the annual use of vertebrates in animal testing (from zebrafish to non-human primates) ranges from hundreds of millions to billions. A large number of laboratory animals as human "stand-ins" are widely used in scientific research, they use their lives to improve human living conditions, deserve our respect and gratitude to them.
Experimental animal monument at the Siberian Institute of Cytology and Genetics in Russia A mouse "weaves" DNA double strands (image from the network)
bibliography:
1. Dahm, Ralf. The Zebrafish Exposed. American Scientist. 2006, 94 (5): 446–53.
2. Wu Benli,Cao Yan,Luo Si,et al. Sensitivity of rare catfish in closed populations to several common chemicals[J].Chinese Journal of Environmental Sciences,2014,34(4): 1059-1066
3. LI Huihui. Genetic structure of IHB rare salamander[D].Beijing:University of Chinese Academy of Sciences,2016.
4. Gu Dangen,Yu Xueying,Wang Jianwei. Monitoring of growth and reproductive performance of Ihb: IHB in the closed population of rare bass carp[J].Chinese Journal of Laboratory Animals,2014, 22(1): 71-75
5. Acute Toxicity Test of Rare Bass Carp of Chemicals (GB/T 29763-2013)
6. Zhang Jingyi,Yin Haowen. Controversy and analysis of rare catfish as an indigenous model organism[J].Acta Ecotoxicologica Sinica,2017,12(02):44-45.
7. https://archive.vn/20120707075236/http://articles.baltimoresun.com/2010-08-26/health/bs-hs-animal-testing-20100826_1_animal-testing-animal-welfare-act-researchers
Source: Institute of Hydrobiology, Chinese Academy of Sciences
Author: Xing Siqi, Wang Xi, Wang Huanshan
Source: Voice of the Chinese Academy of Sciences