Value of FETAX at evaluation of chemical pollutants on development of xenopus laevis embryos

ABSTRACT Over the past twenty years, amphibian species have become popular model animal systems. They are vertebrates and can be maintained easily and inexpensively in laboratory. Among amphibians Xenopus has become one of the amphibian species most widely used in biomedical research. First of our studies was about to care and feeding of Xenopus in laboratory. Our second aim in these studies was to assay to FETAX. We made pilot studies about of FETAX. We studied about of temperature, feeding, aeration, housing, at randomized taken eggs percent ratio of fertilization and at same induction differences of developmental stages of Xenopus laevis per hour collected eggs. It was chosen of Lithium Chloride as chemical agent for FETAX. In conclusion we have seen that the larvae housed about 24- 26°C temperature fed once a day, constantly aerated and should have enough space for the growing juvenil per individual. Most of sufficient development of embryos were find that at per hour collected eggs at fifth hours. But we have not found any literature about of this conclusion. In pilot studies we seen that different anomalies depend on stage of development, time of treating, consantration of the chemical. The effect of Lithium on the larval body pattern could be detected from reduction of posterior structures (anteriozation) to reduction of anterior structures ( posteriozation ), the time of midblastula transition (MBT), could be detected just after the 12 th cleavage. At FETAX at ninety six hour LC50 value for LiCI were 0.002 g/L, and 96 hour EC50 value of LiCI were 0.0088 g/L. The Teratogenicity Index were found about 2.5. This results shown Lithium Chlorid is a moderate teratogen. Keywords: Xenopus, FETAX, Lithium, Feeding, insemination IX