Histochemistry of lectin-binding sites in Halicryptus spinulosus (Priapulida)

TY - JOUR

T1 - Histochemistry of lectin-binding sites in Halicryptus spinulosus (Priapulida)

AU - Busch, A

AU - Schumacher, U

AU - Storch, V

PY - 2001/2

Y1 - 2001/2

N2 - Priapulida represent one of the phylogenetically oldest multicellular animal groups. In multicellular animals (Metazoa) cell-to-cell and cell-to-matrix interactions are often mediated by carbohydrate residues of glycoconjugates. To analyze the carbohydrate composition of a phylogenetically old species, lectin histochemistry was employed on 5 specimens of the priapulid Halicryptus spinulosus. Many lectins bound to the chitin-containing cuticle, including those specific for carbohydrates other than N-acetylglucosamine, the principle building block of chitin. The connective tissue of the animals contained both N-acetylglucosamine and N-acetylgalactosamine. Mannose residues were widely distributed with the exception of the cuticle, but complex type carbohydrates were not present in the entire animal. Sialic acid residues were only detected in the cuticle and brush border of the intestinal epithelium, while fucose was limited to the cuticle. Thus, the lectin-binding pattern indicated that sugars typical for the linking region of both N- and O-glycoproteins in mammals are also present in H. spinulosus. Carbohydrate residues that are typical for the complex type of N-linked glycans in vertebrates are not present as are carbohydrate residues typical for the termination of O-linked carbohydrate chains. Hence, a truncated form of both N- and O-linked glycosylation is present in H. spinulosus indicating that more complex patterns of glycosylation developed later during evolution.

AB - Priapulida represent one of the phylogenetically oldest multicellular animal groups. In multicellular animals (Metazoa) cell-to-cell and cell-to-matrix interactions are often mediated by carbohydrate residues of glycoconjugates. To analyze the carbohydrate composition of a phylogenetically old species, lectin histochemistry was employed on 5 specimens of the priapulid Halicryptus spinulosus. Many lectins bound to the chitin-containing cuticle, including those specific for carbohydrates other than N-acetylglucosamine, the principle building block of chitin. The connective tissue of the animals contained both N-acetylglucosamine and N-acetylgalactosamine. Mannose residues were widely distributed with the exception of the cuticle, but complex type carbohydrates were not present in the entire animal. Sialic acid residues were only detected in the cuticle and brush border of the intestinal epithelium, while fucose was limited to the cuticle. Thus, the lectin-binding pattern indicated that sugars typical for the linking region of both N- and O-glycoproteins in mammals are also present in H. spinulosus. Carbohydrate residues that are typical for the complex type of N-linked glycans in vertebrates are not present as are carbohydrate residues typical for the termination of O-linked carbohydrate chains. Hence, a truncated form of both N- and O-linked glycosylation is present in H. spinulosus indicating that more complex patterns of glycosylation developed later during evolution.

KW - Acetylgalactosamine

KW - Acetylglucosamine

KW - Animals

KW - Biological Evolution

KW - Carbohydrate Metabolism

KW - Carbohydrates

KW - Fucose

KW - Glycoconjugates

KW - Glycosylation

KW - Histocytochemistry

KW - Invertebrates

KW - Lectins

KW - N-Acetylneuraminic Acid

KW - Phylogeny

KW - Staining and Labeling

U2 - 10.1078/0065-1281-00574

DO - 10.1078/0065-1281-00574

M3 - SCORING: Journal article

C2 - 11252632

VL - 103

SP - 9

EP - 19

JO - ACTA HISTOCHEM

JF - ACTA HISTOCHEM

SN - 0065-1281

IS - 1

ER -