Although not typically grouped together in the same category, stem cell technologies share a major goal with synthetic biology: the fabrication of new organs. Early last year, Sasai and colleagues generated a retina in a 3D culture of embryonic stem cells (ESC), and now, they’ve “grown” a portion of a pituitary gland in a “dish.” The key to constructing a hormone-producing gland? Assembly two adjacent layers of epithelial sheets (i.e., ectoderm and neuroectoderm), and then a pituitary primordium, called the Rathke’s pouch, forms at their interface.
Image: (Left) The natural organ: Sagittal section of developing Rathke’s pouch (red) in the mouse embryo on E12. The pituitary primordium (i.e., the Rathke’s pouch) is labeled red with antibodies to Pitx1, while the hypothalamus is green via Rx antibodies.
(Right) The engineered organ: Rathke’s pouches (green and white) self-formed in an ESC aggregate on culture day 13. Green, white, and red are derived from antibodies for Lim3, Pitx1, and Tuj1, respectively. Dapi stains nuclei blue in both images.