A Simple Method for Estimation of the Effects of Environmental Chemicals on the Formation of Primordial Germ Cells (PGCs) Using Embryos and Larvae of Xenopus laevis

Michiko Kamimura Sakamoto

Laboratory of Anatomy and Physiology, Kyusyu Nutrition Welfare University, Shimoitozu 5-1-1, Kokurakita-ku, Kitakyushu, Fukuoka 803-8511, Japan

AATEX 11(2):129-135, 2005

To estimate the developmental toxicity of environmental chemicals on the formation of primordial germ cells (PGCs), Xenopus laevis embryos were exposed to caffeine at 200 mg/l during the migratory stage of presumptive PGCs. The PGC-containing region of the larvae at stage 46, which corresponds to genital ridge, was illuminated by cold light using a halogen lamp and photographed using a digital cam-era under a dissecting microscope. The length along the cephalocaudal axis and area of the PGC-containing region were measured using image-measuring software. The length and area of the PGC-containing region as well as its relative length compared to the 100-µn;m body length of caf-feine-exposed larvae were significantly shorter and smaller, respectively, than those of the control. Though further studies concerning the effect of caffeine on PGC formation are needed, these findings suggest that the Xenopus embryo and larva system examined in this study is useful as a simple, rapid and low-cost initial method for the estimation of the developmen-tal toxicity of environmental chemicals on PGC formation.

Key words: primordial germ cells, developmental toxicity, pre-screening method, Xenopus laevis, caffeine