Abstract
Using an experimental approach similar to that used for Euglena flagella, we found that flagella and flagellar membrane preparations (isoagglutinins) of the
unicellular green algae Chlamydomonas moewusii and C. reinhardtii, but not cells without flagella, bind radiolabelled riboflavin with high affinity
and specificity. In addition, flagella and isoagglutinins contain high amounts of
methanol-extractable flavins. These results indicate an abundance of proteins with
high affinity for riboflavin in the flagella. Since sexual adhesiveness of gametic
flagella in C. moewusii is controlled by light, the possibility is discussed that flavoproteins in the flagella
are involved in this reaction. Action spectra exhibit maxima at 450 and 600 nm, suggesting
- at least for the 450 nm band - a typical blue-light receptor.
Key words
Chlamydomonas
- mating - blue-light receptor - flavoproteins - flagella
