Organogenesis

Organogenesis is the phase of embryonic development that starts at the end of gastrulation and continues until birth. During organogenesis, the three germ layers formed from gastrulation (the ectoderm, endoderm, and mesoderm) form the internal organs of the organism. The cells of each of the three germ layers undergo differentiation, a process where less-specialized cells become more-specialized through the expression of a specific set of genes. Cell differentiation is driven by cell signaling cascades. Differentiation is influenced by extracellular signals such as growth factors that are exchanged to adjacent cells which is called juxtracrine signaling or to neighboring cells over short distances which is called paracrine signaling. Intracellular signals consist of a cell signaling itself (autocrine signaling), also play a role in organ formation. These signaling pathways allow for cell rearrangement and ensure that organs form at specific sites within the organism. The organogenesis process can be studied using embryos and organoids. The endoderm is the inner most germ layer of the embryo which gives rise to gastrointestinal and respiratory organs by forming epithelial linings and organs such as the liver, lungs, and pancreas. The mesoderm or middle germ layer of the embryo will form the blood, heart, kidney, muscles, and connective tissues. The ectoderm or outermost germ layer of the developing embryo forms epidermis, the brain, and the nervous system. While each germ layer forms specific organs, in the 1820s, embryologist Heinz Christian Pander discovered that the germ layers cannot form their respective organs without the cellular interactions from other tissues. In humans, internal organs begin to develop within 3–8 weeks after fertilization. The germ layers form organs by three processes: folds, splits, and condensation. Folds form in the germinal sheet of cells and usually form an enclosed tube which you can see in the development of vertebrates neural tube. Splits or pockets may form in the germinal sheet of cells forming vesicles or elongations.

An automated do-it-yourself system for dynamic stem cell and organoid culture in standard multi-well plates

Matthias Lütolf, Sebastian Maerkl, Hao-An Hsiung, Zoe Newell Swank, Stefano Davide Vianello, Julia Tischler

We present a low-cost, do-it-yourself system for complexmammalian cell culture under dynamically changing medium formulations by integrating conventional multi-well tissue culture plates with simple microfluidic control and system automation. We demonstrat ...

2022

Preparation of Single-Somite Explants from Zebrafish Embryos

Andrew Charles Oates, Sundar Ram Naganathan

The body axis of vertebrate embryos is periodically subdivided into 3D multicellular units called somites. While genetic oscillations and molecular prepatterns determine the initial length-scale of somites, mechanical processes have been implicated in sett ...

JOURNAL OF VISUALIZED EXPERIMENTS2022

Puckered and JNK signaling in pioneer neurons coordinates the motor activity of the Drosophila embryo

An automated do-it-yourself system for dynamic stem cell and organoid culture in standard multi-well plates

Preparation of Single-Somite Explants from Zebrafish Embryos

Preparation of Single-Somite Explants from Zebrafish Embryos

Puckered and JNK signaling in pioneer neurons coordinates the motor activity of the Drosophila embryo

An automated do-it-yourself system for dynamic stem cell and organoid culture in standard multi-well plates