A MULTIXENOBIOTIC TRANSPORTER IN URECHIS-CAUPO EMBRYOS - PROTECTION FROM PESTICIDES

Much is known about how adult organisms protect themselves from exposu re to foreign compounds (xenobiotics), but for a population to success fully colonize a habitat, all life stages of the organism must be able to grow and develop normally in that habitat. In this study, a multix enobiotic transporter is described which is similar to the multidrug t ransporter in mammalian cells, used by some embryos as protection from natural xenobiotics they may encounter in their environment. It is sh own that some moderately hydrophobic pollutants - but not very hydroph obic pollutants - are competitive substrates of the multixenobiotic tr ansporter in the embryos of a marine worm. Multixenobiotic resistance may protect Urechis caupo embryos from certain toxic substances by pre venting their entry into cells. In this way the xenobiotics cannot int erfere with cellular processes that are crucial for normal development , such as DNA synthesis, cell division, and gene transcription.