Temporal and constitutive expression of homeobox-2 gene (Hu-2), human heat shock gene (hsp-70), and oncogenes C-sis and N-myc in early human trophoblast

Recent studies of the genetic basis of animal development indicate that homeobox genes, protooncogenes, and some heat shock genes may play a role in early embryogenesis. To investigate the possibility that these genes function in early human embryonic development, we monitored the expression of a human homeobox gene (Hu-2), two human protooncogenes (C-sis and N-myc), and a human heat shock gene (hsp-70) in human trophoblasts at 7 to 13 weeks gestational age. All these genes were found to be expressed in the tissues analyzed. The hsp-70 gene was expressed at nearly constant levels throughout the developmental period surveyed, whereas N-myc, C-sis, and Hu-2 showed a coordinated pattern of regulated expression. These results are consistent with a functional role of these genes in the early course of human development.