Algae. 2009; 24(1): 39-45.
Conjugation Process in Spirogyra varians Monitored with FITC-lectins (Zygnemataceae, Chlorophyta)
Minchul Yoon1, Man Kyu Kim2 and Gwang Hoon Kim1*
1Department of Biology, Kongju National University, Kongju, Chungnam 314-701, Korea
2Department of Geology, Kongju National University, Kongju, Chungnam 314-701, Korea
The conjugation processes of a filamentous freshwater green alga Spirogyra varians were examined using FITClectins. Conjugation comprised five steps: 1) aligning with adjacent filaments, 2) formation of conjugation protrusion (papilla), 3) fusion of the protrusions, 4) formation of conjugation tube, and 5) formation of zygotes. Three lectins, ConA, RCA and UEA, showed considerable labeling during the progression of conjugation. FITC-ConA labeled the surfaces of filaments throughout the whole conjugation processes. FITC-RCA labeling was observed at the conjugation protrusions only after the papilla formation. Strong labeling continued until formation of zygotes at the contacting area where the conjugation tube developed, but no labeling was detected on the surface of vegetative filaments. The labeling decreased gradually over time and disappeared when zygotes were formed. FITC-UEA showed similar labeling pattern with FITC-RCA except that weak labeling remained after zygote formation. Inhibition experiments using RCA, UEA which are complementary to sugars L-fucose and D-galactose, showed considerable decrease of conjugation (< 32% vs. 70% in control). These results suggested that the lectin-carbohydrate recognition system might be involved in the conjugation of Spirogyra varians.
Keywords : conjugation, FITC-RCA, FITC-UEA, lectin-carbohydrate recognition, Spirogyra varians