Table 1.
Characterized gene promoters effective in targeting trophoblast lineages in vivo
Gene | Function/Expression | Relevant promoter regions necessary for trophoblast-specific expression | Relevant References |
---|---|---|---|
Adenosine deaminase | Purine metabolizing enzyme; expressed in all mouse trophoblast subpopulations beginning at mid-gestation. | 770-bp region situated 5.4 kb upstream of transcription start site; contains binding site for trophoblast-specific element binding protein. | [9,10] |
CYP19 | Aromatase complex; converts androgens to estrogens; expressed in human, but not mouse placenta. The human promoter is active in the mouse placenta. | 501-bp 5′-flanking region of placenta-specific Cyp19 exon I.1. | [30–32] |
Eomesodermin | Regulation of trophoblast lineage specification; expressed in TS cells and early trophoblast cells, primitive streak, telencephalon. | 180-kb 5′-sequence on bacterial artificial chromosome sufficient to drive expression. | [25] |
Growth hormone releasing hormone | Hypothalamic hormone that stimulates release of growth hormone; expressed by rodent placenta; expression commences at mid-gestation and continues increasing until term. | 7.5-kb-5′ flanking region and sequences downstream to exon 1. | [24] |
Human chorionic somato-mammotropin | Human growth hormone gene cluster; expressed in human syncytiotrophoblast at mid-gestation. No mouse homologue, but transcriptionally active in mice. | Histone acetylation and differential protein binding within a remote locus control region 14–32 kb upstream of gene cluster. | [27–29] |
Placental lactogen II (PL-II; Prl3b1) | Member of expanded rodent prolactin-like protein superfamily; expressed by rodent trophoblast giant cells and in mice, spongiotrophoblast cells beginning at mid-gestation. | 2019 to 1340 bp upstream of transcription start site; contains elements for GATA, Ets, and AP-2γ factor binding. | [12–14] |
Renin | Involved in regulation of blood volume and blood pressure; expressed in fetal adrenal gland, Wolffian duct, and trophoblast giant cells during mid-late pregnancy. | 4-kb 5′-flanking region. | [23] |
Tpbpa (4311) | Unknown function; expressed in junctional zone trophoblast. | 340-bp region situated 3740 bp upstream of transcription start site. Contains E-box binding elements for basic helix-loop-helix transcription factor binding. | [21,22] |