Comparative studies on carbohydrates of several myxosporean parasites of fish using lectin histochemical methods

A histochemical study using lectin methods was performed on myxosporsan par asites from vastly different fish hosts from marine and fresh waters. Six b iotinylated lectins were used (WGA, SEA, BS-I, Con-A, UEA-1 and SNA). The b inding pattern of Con-A and WGA revealed the presence of mannose and/or glu cose, and N-acetyl-D-glucosamine respectively, in polar capsules and valves of most of the myxosporea assayed. Thus, chitin may be present in polar ca psules and/or valves of myxosporean spores. The BS-I binding pattern showed the presence of a-D-galactose and/or N-acetyl-D-galactosamine residues in polar capsules of Kudoa sp., Zschokkella mugilis Sitja-Bobadilla et Avarez- Pellitero, 1993 and Leptothecn sp., and in the valves of the latter. Scarce amounts of N-acetyl-D-galactosamine and/or a-D-galactose were demonstrated bq SBA binding in Sphaerospora dicentrarchi Sitja-Bodabilla ct Alvarez-Pel litero 1992, Leptotheca sp. and Kudoa sp. valves, and in Leptotheca sp, pol ar capsules. The UEA-1 staining indicated the absence of alpha-L-fucose in all the Leptotheca assayed except in Leptothecn sp. N-acetylneuraminic acid was detected with SNA in the polar capsules and sporoplasms of Polysporopl asma sparis Sitja-Bobadilla et Alvarez-Pellitero, 1995 and in the polar cap sules and valves of kudoa sp. These results indicate that, although Myxospo rea may have conserved carbohydrate structures, some of them can show signi ficantly different binding patterns, which may be useful in diagnostic and functional studies.