Heterogeneity of chondroitin sulfate glycosaminoglycan localization during early development of the striped bass (Morone saxatilis)

Abstract

Recent studies have suggested important functions for proteoglycanassociated chondroitin sulfate glycosaminoglycans (GAGs) during embryonic and larval development in numerous organisms, including the teleost. Little is known, however, about the specific distribution of different chondroitin sulfate GAGs during early development. The present study utilized immunohistochemistry to localize chondroitin sulfate GAG antigens during development of the striped bass (Morone saxatilis). Immunoreagents utilized were monoclonal antibodies (MAbs) TC2, d1C4, and CS-56, which recognize, respectively, native epitopes on glycosaminoglycan chains enriched in chondroitin-4-, chondroitin-6-, and both chondroitin-4-and -6-sulfate. Little or no immunoreactivity was observed in gastrulating embryos at 18 hr postfertilization with any MAb tested. By 24 hr (8 somites), the CS-56 epitope was localized around the notochord. At hatching (48 hr) and early larval (72 hr) stages, d1C4 and CS-56 antigens codistributed in some sites (e.g., the notochord and myosepta), but a striking heterogeneity of chondroitin sulfate GAG localization was observed in other developing tissues, including the eye and specific subsets of basement membrane. At these latter time points, TC2 reacted primarily with the extracellular matrix of the developing heart, particularly the ventricular and conotruncal segments. Heterogeneous patterning of these chondroitin sulfate GAG epitopes suggests dynamic regulation of proteoglycan function during critical morphogenetic events in early development of the striped bass. Anat

Heterogeneous Expression of Chondroitin Sulfate Glycosaminoglycans and Versican Proteoglycan during Early Development of Rathke’s Pouch

“…Lectican family chondroitin sulfate proteoglycans (CSPGs) are important constituents of the ECM that are also selectively expressed in various embryonic basement membranes [16,17] and function in numerous roles including matrix organization, growth, migration, and cell differentiation. One lectican CSPG, versican, has widespread distribution in the early embryonic ECM and its misexpression has been shown to disrupt cardiac [18], limb [19,20], and joint development [20,21].…”

“…Many CSPG functions are due to their complement of glycosaminoglycan (GAG) chains [22,23] which may vary on a core protein dependent on tissue location and developmental stage. Heterogeneity of CS-GAGs in developing organs has been shown to correlate with key developmental events [17], suggesting that particular CS-GAG structure (e.g., pattern and degree of sulfation) may be important in regulation of specific morphogenetic processes.…”