What is notochord? What is its function?

The notochord is a flexible rod-like structure found in the embryos of all chordates, which includes vertebrates (animals with a backbone) and some invertebrates. It is one of the defining characteristics of chordates and plays a crucial role in early development.

The notochord is initially formed from a group of cells called the notochordal plate during embryonic development. It runs along the length of the body, just below the neural tube (which eventually develops into the spinal cord). In vertebrates, the notochord is later replaced by the spinal column or vertebral column.

The main function of the notochord is to provide support to the developing embryo. It acts as a primitive axial skeleton, providing a rigid structure that helps maintain the overall shape and stability of the embryo during early stages of development. The notochord also serves as an important signaling center, influencing the patterning and differentiation of nearby tissues.

Furthermore, the notochord plays a crucial role in inducing the formation of the neural tube. It secretes signaling molecules that instruct the overlying ectoderm (the outermost layer of cells) to fold and form the neural tube, which gives rise to the central nervous system.

In summary, the notochord provides structural support, acts as a signaling center, and initiates the formation of the neural tube during embryonic development in chordates.