TURKISH JOURNAL OF BIOLOGY, vol.24, pp.177-188, 2000 (Peer-Reviewed Journal)
Abstract: The main goal was to standardize the FETAX (Frog Embryos Teratogenesis Assay: Xenopus)
test. Since lithium ions are known to be teratogenic for embryos of many organisms, they were
prefferred for our first standardization assay. Xenopus laevis embryos were exposed to lithium
chloride (from 2x10–4 to 6 x 10–3 M concentrations) for 96 hours at 2–4 cell stages of development.
Exposure to lower LiCl concentrations permitted larvae to survive and to develop into normal ones.
On the other hand, depending on the increase in the LiCl concentration, the body length and survival
rate (%) decreased. In addition, the decreased survival and increased malformation rates were shown
to be parallel with the increased concentration rates. The most common abnormalities were found to
be tail kinks and edema. The less frequents abnormalities were microcephaly, cyclopia, shortening of
the trunk (micromyelia), depigmentation, macrocephaly, spina bifida, anteriozation, posteriozation,
medially located eyes and abnormally of the yolk.
In the Fetax test, at ninety–six hours, LC50 value was 0.002 g/L, and EC50 value was 0.0088g/L for
lithium chloride. Finally, the teratogenicity index was found to be about 2.5. These results showed that
lithium chloride was a moderate teratogen.
Key Words: Xenopus, FETAX, Teratogenicity, Malformation, Insemination.