Time and mode of synthesis of the sexual inducer glycoprotein of Volvox carteri

Abstract

The synthesis of the sex-inducing glycoprotein of Volvox curferi was investigated. A highly specific antiserum directed against pheromone deglycosylated with trifluoromethane sulphonic acid was used to detect inducer protein in maturing cultures of the male strain IPS-22. Immunoblot analysis showed that inducer synthesis is restricted to a very late phase of sperm development, a few hours before the sperm cells die. The pheromone is co-translationally glycosylatcd to yield a well-defined pattern of isoinducers.

Adenylyl Cyclase from the Green Alga Volvox carteri f . nagariensis: Partial Purification and Characterisation

“…Furthermore, in the presence of the sexual inducer, a sexuality inducing pheromone, the pattern of unequal cell divisions is altered and gametes are formed. This sexual inducer is only produced and secreted by free swimming sperm packets containing the male gametes (Balshiisemann and Jaenicke 1990~). Its action is species-specific or even subspecies-specific (Al-Hasani and Jaenicke 1992) with threshold concentrations as low as 10-l6 M in Volvox carteri f. nagariensis (Gilles et al 1984~).…”