Common and Specific Features of Organization of the Yolk Syncytial Layer of Teleostei as Exemplified in Gasterosteus aculeatus L.

The structure of the yolk syncytial layer (YSL) of late embryos and larvae of the three-spined stickleback Gasterosteus aculeatus L. has been studied by histological methods. The YSL structure in this species has specific features that are related to the process of yolk utilization and features that are common for YSL of bony fishes, which are the structural regionalization, large polymorphic nuclei, and enclosing of the lipid droplets in YSL. We summarize original and published data on the diversity of YSL in bony fishes. The comparison is made for YSL and other structures that metabolize yolk in embryos in various animal taxa.