Meta-Biol

• Pathways

The levels of second messengers such as Ca+2, cAMP and cGMP may regulate the response of the growth cone to a particular cue. Netrin-1 as a guidance molecule depends on intracellular Ca+2 concentration, coactivation of PI3K and PLCgamma, and the type of response depends on the levels of cAMP. Netrin first stimulates its receptor DCC, resulting in the activation of the enzyme phospholipase C. This then produces the messenger molecules, inositol-1,4,5-trisphosphate (IP3) and DAG, which in turn causes the release of Ca+2 from intracellular stores. Ca+2 release from the stores then activates TRPC channels on the cell surface. DAG activates TRPC3 and TRPC6 in a direct, membrane delimited manner, and IP3 may activate TRPC channels by depleting the ER Ca+2 levels.

Neurogenesis is the process by which neural stem cells give rise to neurons, and occurs both during embryonic and perinatal development as well as in specific brain lineages during adult life (reviewed in Gotz and Huttner, 2005; Yao et al, 2016; Kriegstein and Alvarez-Buylla, 2009).

As early steps towards capturing the array of processes by which a fertilized egg gives rise to the diverse tissues of the body, examples of several processes have been annotated. Aspects of processes involved in most developmental processes, transcriptional regulation of pluripotent stem cells, gastrulation, and activation of HOX genes during differentiation are annotated. More specialized processes include nervous system development , aspects of the roles of cell adhesion molecules in axonal guidance and myogenesis, transcriptional regulation in pancreatic beta cell, cardiogenesis, transcriptional regulation of granulopoeisis, transcriptional regulation of testis differentiation, transcriptional regulation of white adipocyte differentiation, and molecular events of "nodal" signaling, LGI-ADAM interactions, and keratinization.