THE LURLENES, A NEW CLASS OF PLASTOQUINONE-RELATED MATING PHEROMONES FROM CHLAMYDOMONAS-ALLENSWORTHII (CHLOROPHYCEAE)

Chlamydomonas allensworthii is a recently described species, which dif fers phenotypically and in its reproductive behaviour from other membe rs of this genus of flagellated green protists. Its female cells tempo rarily or constantly excrete a luring signal into the medium to attrac t the male cells for mating. The sperm is susceptible to the pheromone either all the time or only after a maturation process. Maturation in this species is accompanied with a colour shift from green to khaki ( strain from Lemon Cove CA) or to olive (strain from Catarina TX), appa rently due to degradation of chloroplast material. In the bioassay wit h polyacrylamide beads (plain or DEAL-substituted) to which the lures are bound, acting as mock females, Catarina-strain males are only attr acted to Catarina strain lures, whereas Lemon-Cove-strain males are at tracted to Lemon-Cove-strain lures and to a lesser extent, to Catarina -strain lures. Being amphiphilic acid, Lemon-Cove-strain lure is more tightly bound to DEAE beads. Catarina-strain lure is an uncharged amph iphile. The two signal compounds have been isolated and identified by chemical analysis and mass and NMR spectroscopies as 0(5)-beta-D-xylos ylated degradation products of the chloroplast electron transporter hy droplastoquinone, its polyprenoid side chain being oxidatively cleaved at the fourth double bond. Lurlenic acid (lurlene L) is the resulting acid and lurlenol (lurlene C) the corresponding alcohol. The pheromon al activities of both compounds have a threshold at 1 pM, and are dest royed by deglycosylation and subsequent oxidation to the quinonoid agl ycon. This class of amphiphilic lures, having the same basic glycosyla ted hydroquinone structure, is named lurlenes.