[The expression of the apolipoprotein A-1 gene in the early stages of human embryogenesis studied by hybridization in situ].

The apolipoprotein A-1 (apo A-1) gene expression at certain stages of human embryo development was studied using an in situ hybridization procedure. By the fifth week of development, the presence of apo A-1 mRNAs was detected in cells of different tissue types such as CNS rudiment, somite myotomes, ear vesicle, nasal placodes, lens, apical areas of the maxillary, mandibular and hyoid arcs, mesenchyme of limb buds, small intestine, mesonephros, genital ridge, and several types of blood cells. At later stages (weeks 8-9) the distribution of these mRNAs showed considerable changes. The high apo A-1 mRNA level was characteristic of liver cells, adrenals, kidney, neural tube and ganglia. These data suggest that changes in tissue-specific apo A-1 gene expression during human embryogenesis may be associated with the development of blood circulatory system and CNS.