Where do the cells that produce the kidney come from What re

Where do the cells that produce the kidney come from? What reciprocal interactions are required to generate the adult kidney? What are the molecular signals required for this process? Be sure to cite experimental evidence to support your answer.

Solution

Formation of the Kidney, one of the major internal organs responsible for the regulation of body temperature and elimination of waste comes from the epithelial and mesenchymal cells.

The process of Kidney Development, also known as Nephrogenesis comprises of three stages of the developmental phases, the pronephros (third week of embryonic development), mesonephros (four weeks) and metanephros (at five weeks).

The \'Reciprocal Induction\' leads to the formation of Kidney wherein the mesodermal derivatives, viz. the Embryonic Bud (or Embryonic Epithelium) and mesenchyme interacts and development initiates. It is the Embryonic Bud which after getting branched forms the collecting ducts whereas the mesenchyme forms the distal and proximal tubules together with glomeruli.

The Molecular Signals Required During the Kidney Development:

1.) GDNF/RET Signaling ----> It plays an important role during the Uninary Bud formation and is equally important for the branching of Urinary Bud.

2.) FGF (Fibroblast Growth Factors) Signaling ----> Responsible for early metanephric developmental phase and transfer the signals to the FGF receptors. Two major types include, fgfr1 and fgfr2

3.) Six 1 and Sall 1 Signaling ----> Both Six 1 and Sall 1 found in the MM are important for the Urinary Bud and WD growth. Six 1, a homeobox protein is responsible for early kidney development whereas Sall 1 plays an influential role in the development of metanephros, and is ranked among one of the multi-zinc finger transcription factors.

4.) Wnt Signaling ----> Wnt are expressed both in the Urinary Bud and metanephric mesenchyme, and the Wnt Signalling between these two helps to induce and regulate the kidney growth (or nephrogenesis).