Life history of an organizer: what determins transient orgnaizer function in Hensen's node? (360G-Wellcome-105381_Z_14_A)

The "primary organizer" of the vertebrate embryo is a group of cells at the gastrula stage which is able to induce a complete patterned nervous system when transplanted to another site. However, the position in the embryo where the organizer is located only has these properties for a short time. This time corresponds to when two particular populations of cells ("central epiblast" and "posterior deep") come together. After this, as cells leave to form the prechordal mesendoderm, organizer ability is lost again. The aim of this project is to find out whether the organizer function of Hensen's node is the sum of properties that exist in separate cell populations or whether new properties are generated by interactions between them, and thus determine how dynamics of these cells contribute to the transient nature of organizer function. Cell dynamics will be studied using carbocyanine dye (Dil and DiO) labelling of the 'central' and 'posterior' populations to identify their contributions and roles in the organizer. These populations, individually and combined, will be assessed by studying their transcriptomes by RNA sequencing. Their organizer function will then be assessed, in time-course, by the gene expression profiles in cells receiving signals from these populations