Table 1.
Examples of tissues and organs induced from Xenopus animal caps by activin and other factors
| Tissues and organs | Methods | Notes | Markers | References |
|---|---|---|---|---|
| Ectoderm | ||||
| Epidermis | Animal cap assay (Steps 11–13) | Induced by 0.5–50 ng/mL activin | xk81a1 | Asashima et al. 1990; Ariizumi et al. 1991 |
| Brain (forebrain, hindbrain); Spinal cord | Combination of treated and untreated animal caps | Induced from untreated animal caps by animal caps treated with >50 ng/mL activin | otx2, sox2, foxg1 | Ariizumi and Asashima 1994 |
| Eye (lens, neural retina, retinal pigment epithelium); Ear vesicle | As above | Induced secondarily from brain | pax6, six3, rax | Ariizumi and Asashima 1994; Sedohara et al. 2003 |
| Mesoderm | ||||
| Notochord | Animal cap assay (Steps 11–13) | Induced by high concentrations (>50 ng/mL) of activin | chrd, not | Asashima et al. 1990; Ariizumi et al. 1991 |
| Skeletal muscle | As above | Induced by intermediate concentrations (5–50 ng/mL) of activin | myod, myf5, mrf4 | Asashima et al. 1990; Ariizumi et al. 1991 |
| Coelomic epithelium | As above | Induced by low concentrations (0.5–5 ng/mL) of activin | — | Asashima et al. 1990; Ariizumi et al. 1991 |
| Blood cells; Blood vessel | As above | Induced by low concentrations (0.5–1 ng/mL) of activin | runx2, spib, mpo | Asashima et al. 1990; Ariizumi et al. 1991; Miyanaga et al. 1999; Nagamine et al. 2007 |
| Pronephros (glomus, tubule, duct) | Multiple treatments with activin and retinoic acid (Steps 14–15) | Induced by simultaneous treatment with 10 ng/mL activin and 0.1 mm retinoic acid | wnt4, pax2, sall1, wt1 | Moriya et al. 1993; Chan et al. 1999; Osafune et al. 2002 |
| Heart | Dissociation and reaggregation of animal cap cells (Steps 21–24) | Individual cells are treated with 100 ng/mL activin during reaggregation | nkx2.5, gata4, tbx5, tnni3 | Ariizumi et al. 2003 |
| Craniofacial cartilage | Combination of treated and untreated animal caps | Induced from untreated animal caps by animal caps treated with 100 ng/mL activin | dll4, col2a1, alx1 | Furue et al. 2002 |
| Endoderm | ||||
| Pharynx; Intestine | Combination of treated and untreated animal caps | Animal caps treated with >50 ng/mL activin form pharynx and intestine in recombinants | fabp2, darmin | Ariizumi and Asashima 1994 |
| Pancreas | Multiple treatments with activin and retinoic acid (Steps 16–19) | Induced by sequential treatment with 100 ng/mL activin and 0.1 mm retinoic acid | pdx1, mist1, ins | Moriya et al. 2000 |
| Liver | Animal cap assay (Steps 11–13) | Yolk-rich endoderm induced by 100 ng/mL activin forms liver when transplanted into larvae | hhex, ambp, transferrin, albumin | Ariizumi et al. 2003 |
