Sialylated glycoproteins and sialyltransferases involved in mesoderm-derived organ formation during embryogenesis.

Most major organs, like muscles, bones, vessels and kidneys, develop from the mesoderm, one of three germ cell layers in triploblastic organisms. Sialic acids significantly affect embryonic development by regulating cell division, migration and death through signaling pathways and cell adhesion, which support morphogenesis. Loss of early biosynthetic enzymes reduces embryonic viability and leads to complex phenotypes, while the loss of terminal enzymes primarily results in tissue-specific defects in mesoderm-derived organs. Key sialylated glycoproteins involved in the developmental processes of mesoderm and mesoderm-derived organs have been identified across various species as major effectors. These enzymes and glycoproteins are of significant interest and are discussed in the present review.