Nucleus pulposis is derived from:

The nucleus pulposus is the sole remnant of the embryonic notochord, the initial longitudinal skeletal axis of the body. The developing bodies and interveebral discs of the veebral column replace the notochord. NOTOCHORD: The notochordal plate becomes the centrally placed notochord, which acts as a foundation around which the veebral column develops. It extends throughout the entire length of the future veebral column, and reaches as far as the anterior end of the mid-brain, where it ends in a hook-like extremity in the region of the future dorsum sellae of the sphenoid bone. The notochord then undergoes involution and becomes the nucleus pulposus of the intervetebral disks. Remnants of the notochord: are located in the nucleus pulposus, clivus, nasopharyngeal notochordal bursa, and sacrum.The most common anomaly due to incomplete resorption of notochord is butterfly veebra. Nucleus pulposis: The nucleus pulposus is 70-90% water although the exact propoion varies with age. Proteoglycans are the next major component, and they constitute about 65% of the dry weight of the nucleus. Type II collagen is seen interspersed in the proteoglycan medium.It functions to distribute hydaulic pressure in all directons of the disc. It is present in the middle of the veebral disc. Ref: Clinical Anatomy of the Lumbar Spine And Sacrum, By Nikolai Bogduk,4th Edition,Page 19