The specific aim of this research planning grant for women is to identify and subsequently characterize cytochrome P450 enzymes expressed during murine embryonic development. This will be accomplished initially by screening tissue sections of mouse embryos using in situ hybridization and radiolabeled probes encoding known P450 enzymes. Probes that hybridize specifically will be used to characterize the temporal pattern and cellular sites of expression of P450 transcripts during embryogenesis. Identification of specific hybridizing transcripts will be accomplished using techniques such polymerase chain reaction, molecular cloning and sequencing. Once cloned, endogenous P450 transcripts can be expressed in host cells and the functional activities of specific murine P450 gene products can be characterized. The purpose for carrying out these studies is to identify chemicals produced by embryos that are important in regulating normal developmental processes. It is proposed that the production and degradation of such regulatory compounds involves members of a large family of enzymes known as cytochrome P450 which metabolize a wide range of chemical compounds in almost every tissue of the body. By utilizing a plethora of available molecular tools to study P450 enzymes, it should be possible to identify and then to characterize the functional activities of those P450 enzymes expressed during embryogenesis. This knowledge will provide considerable insight into which endogenous compounds or chemicals are produced by embryos and what role they might play in regulating normal fetal development.
