[Animal Experiment]-Biological characteristics and application of swordtail fish

  The swordtail fish (Xiphophorushelleri) belongs to the medaka family. The body shapes of male and female fish are completely different. The male fish is elongated, some fins on the lower caudal fin extend into a sword shape, and the anal fin becomes a reproductive fin. A highly adaptable tropical fish that can grow well in water temperatures of 20-30°C. Swordtail fish reproduce oviparously, and the larvae can live independently of their mother. The male is fertilized through the fin. During breeding, keep the water temperature between 22 and 27°C. Swordtail fish have a gender reversal phenomenon. The female fish body gradually becomes thinner, the round fin gradually becomes rod-shaped, and the lower end of the tail fin grows into a "sword-shaped" protrusion to become a male fish. Swordtail fish somatic chromosome: 2n = 48. There are mainly three strains of swordtail fish, RR-B, RW-H and BY-F. Among them, the typical RR-B swordtail has been crossed for 24 generations and has the characteristics of jealous red. From the analysis of morphological characteristics, isozymes, RAPD, etc., this population has good genetic homogeneity. Its purpose is:

  (1) Establish a disease model

  Artificial infection experiments with fish pathogens show that swordtail fish has a larger mortality gradient among highly virulent, highly virulent and attenuated strains. The affected fish are similar and comparable to mice. Compared with the original generation, the higher-generation swordtail individuals of inbred lines have more consistent responses to pathogens, and the time of death after infection is relatively concentrated. Suitable for the pathogenicity of fish pathogens. Evaluation and construction of disease models. In addition, there are many mutational features suitable for animal models, such as blindness and deformation.

  (2) Drug safety assessment and environmental monitoring

  is sensitive to a variety of pesticides, heavy metals and other toxic substances. In the application of water environment monitoring, swordfish are found to have environmental estrogenic effects on nonylphenol and petroleum, such as pollutants, phenols, alkylbenzenes, nitrobenzene compounds, chromium, copper, lead, mercury and other heavy metals. It is expected that the development of heavy metals will have good applications. Commonly used organophosphorus pesticides such as trichlorfon, malathion and methamidophos, and pyrethroid pesticides such as cypermethrin and deltamethrin are also highly sensitive, and they are used in aquatic drugs. . This is a very representative safety assessment. SwordtailR-B series is a kind of aquatic laboratory animal, suitable for aquatic environment monitoring, aquatic drug safety assessment, chemical toxicity test, animal disease test model and genetic biology research.