Heterogenous distribution of glycoconjugates in the kidney of dogfish Scyliorhinus caniculus (l.) with reference to changes in the glycosylation pattern during ontogenetic development of the nephron

Abstract

Eight fluorochrome-coupled lectins with different sugar specificities were applied to cryosections of dogfish kidney. Despite profound differences in renal architecture between elasmobranch fish and other vertebrates, the sequence of nephron segments as revealed by the lectin-binding pattern was rather similar to that of tetrapodes. Wheat germ agglutinin (WGA) bound to cell membranes of epithelial cells of glomeruli, proximal and distal tubules, their basement membranes, the collecting tubule, and epithelial cells. Among other broadly binding lectins were Ricinus communis agglutinin I (RCA-I), soybean agglutinin (SBA), peanut agglutinin (PNA), Lycopersicon esculentum agglutinin (LEA), and Jacalin, all of which marked proximal as well as distal portions of the renal tubule. Dolichos biflorus agglutinin (DBA) did not react with any renal structure. Ulex europaeus agglutinin I (UEA-I), which indicates the presence of alpha-L-fucose, very strongly and specifically marked single epithelial cells of the early distal nephron, all epithelial cells of the late distal tubule, the beginning of the collecting tubule in the mesial tissue zone, and single cells in the end portion of the collecting tubule in the lateral bundles. Binding of UEA-I to receptors of distal nephron cells could be useful for the identification of these cells in functional studies employing teased tubule and/or isolated cell preparations. Binding of UEA-I to dogfish kidney structures resembles staining with UEA-I conjugates of late distal tubules and collecting tubules in the kidneys of frog and other, higher vertebrates. Epithelial cells of early developmental stages showed, very rarely, binding sites for most lectin-fluorochrome conjugates. A large number of lectin binding sites was observed in the extracellular matrix of fibroblast layers surrounding the early anlage and the S-shaped body. Lectin binding sites of the nephron epithelia appeared in a sequential manner in the next stages of development of the nephron. Ontogenetic and phylogenetic aspects of the merging region between nephron proper (late distal tubule) and collecting system (collecting tubule) are discussed.

Renal corpuscle of the sturgeon kidney: An ultrastructural, chemical dissection, and lectin‐binding study

“…To our knowledge, the presence of N-acetylglucosamine in the podocyte glycocalyx is an exceptional characteristic in the vertebrate kidney. Although dogfish podocytes exhibit pronounced binding of WGA (Hentschel and Walther, 1993), the specific sugar responsible for this binding has not been characterized. Thus, a direct comparison cannot be made between the two species.…”

Nephrogenesis Is Induced by Partial Nephrectomy in the Elasmobranch Leucoraja erinacea

“…Large-scale nephron loss is therefore not accompanied by new nephron generation ("neo" nephrogenesis) in mammals. Furthermore, a detailed analysis of nephron anlagen and developing nephrons in the lesser spotted dogfish, Scyliorhinus caniculus, has been published (10,11). Adult sexually mature bony fish (teleosts) can develop new nephrons as shown in light and electron microscopic studies (6,7).…”

Glycoconjugate expression in the chick embryonic chorioallantoic membrane: Comparisons of the chorionic ectoderm and allantoic endoderm

“…UEA-I, which binds a-L-fucose, failed to bind to ei-ther chick mesonephros tubular epithelium or adult gall bladder epithelium (Gheri et al, 1990;Madrid et al, 1989). Dogfish kidney tubular epithelium, however, was labeled with UEA-I during late stages of development (Hentschel and Walther, 1993). We observed binding of this lectin to the endoderm at days 4.5 to 5.0, but it subsequently disappeared through day 10.…”

“…Dogfish kidney tubular epithelium, however, was labeled with UEA-I during late stages of development (Hentschel and Walther, 1993). We observed binding of this lectin to the endoderm at days 4.5 to 5.0, but it subsequently disappeared through day 10.…”