Lack of keratan sulphate in the human notochord

Intervertebral discs, formed from notochord cell expansions during embryogenesis, are known to contain proteoglycans bearing keratan sulphate chains. Keratan sulphate has previously been demonstrated in Xenopus and chick notochords and in human fetal cartilage. In contrast, we have been unable to demonstrate keratan sulphate in human fetal notochord using two monoclonal antibodies, MZ15 and 5-D-4. The contribution made by notochordal-derived keratan sulphate to the glycosaminoglycan content of the mature intervertebral disc may differ in man from that of other animal species.