Histochemical study of lymphocystis disease in skin of gilthead seabream, Sparus aurata L.

C. Sarasquete1, M.L. González de Canales2, J. Arellano1, S. Pérez-Prieto3, E. García-Rosado4 and J.J. Borrego4

1Instituto de Ciencias Marinas de Andalucía, Puerto Real, Cádiz, 2Departamento de Biología Animal, Vegetal y Ecología, Facultad de Ciencias del Mar, Universidad de Cádiz, Puerto Real, Cádiz, 3Centro de Investigaciones Biologícas, C.S.I.C., Madrid and 4Departamento de Microbiología, Facultad de Ciencias, Campus Teatinos, Malaga, Spain

Offprint requests to: Dr. C. Sarasquete, Instituto de Ciencias Marinas de Andalucía, C.S.I.C., Polígono Rio San Pedro, Apdo. Oficial, 11510, Puerto Real, Cádiz, Spain. e-mail: carmen.sarasquete@icman.csic.es

Summary. A battery of horseradish peroxidase-conjugated lectins (Con A, WGA and DBA), as well as conventional histochemical techniques (PAS, saponification, Alcian Blue pH 0.1, 1, 2.5, chlorhydric hydrolisis, sialidase, Bromophenol blue, Tioglycollate reduction and Ferric-ferricyanide-FeIII) were used to study the content and distribution of carbohydrates, proteins and glycoconjugate sugar residues on the skin and on the lymphocystis-infected cells of gilthead seabream, Sparus aurata. Variable amounts of glycoproteins containing sialic acid, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, mannose and/or glucose residues were observed in the cuticle and mucous cells of the corporal skin, tails and fins. Germinative and epithelial cells of the epidermis contained glycogen, proteins, carboxylated groups, as well as glycoproteins with mannose and/or glucose and N-acetyl-D-galactosamine residues. Hyaline capsule of the mature lymphocystis-infected cells was strongly stained with PAS, Alcian Blue (pH 0.5 and 2.5) and weakly positive with Alcian Blue (pH 1). Con A reacted with the granular cytoplasm, specially around hyaline capsule, and with the basophilic intracytoplasmic inclusions developed in mature lymphocystis-infected cells of Sparus aurata skin. These sugar residues (mannose and/or glucose), as well as N-acetyl-D-glucosamine and/or sialic acid and N-acetyl-D-galactosamine were not detected in the hyaline capsule of the lymphocystis disease. Histol Histopathol 13, 37-45 (1998)

Key words: Skin, Lymphocystis disease, Glycoproteins, Carbohydrates, Proteins, Histochemistry, Sparus aurata

DOI: 10.14670/HH-13.37