Organ distribution of apolipoprotein gene transcripts in 6-12 week postfertilization human embryos.

In the liver and the yolk sack of 6-12 week postfertilization human embryos, we have detected RNA transcripts from the following apolipoprotein genes: AI, AII, B, CII, CIII and E. The mRNA from the apolipoprotein CIII gene was relatively more abundant in the total RNA from the yolk sack than in that from the liver. The gut and adrenals contained transcripts of all these apolipoprotein genes apart from apolipoprotein AII. The kidneys and heart contained some apolipoprotein transcripts. In conjunction with previous studies, these results suggest that in the human embryo apolipoprotein genes are transcribed in a much larger range of organs than is the case in the adult. Many of these organs lack endoderm tissues.