Abstract
Closterium peracerosum-strigosum-littorale complex have two sexes, mating-type plus (mt+) and minus (mt-) cells, and sexual reproduction in this species was easily induced in the laboratory. Two sex pheromones (PR-IP Inducer and PR-IP) were isolated and characterized. In addition, two sex pheromones, sexual cell division-inducing pheromone (SCD-IP-minus and SCD-IP-plus), were detected and evaluated.
SCD-IP-minus was released from mt- cells and induced the SCD of mt+ cells and vice versa. Partially purified SCD-IP-minus showed quite similar characters to PR-IP Inducer, which induced the production of PR-IP in mt+ cells. Moreover, recombinant PR-IP Inducer produced in yeast induced the SCD of mt+ cells as well as the production of PR-IP in mt+ cells. The SCD could be induced by rather shorter period of treatment with the pheromone than the latter. It was strongly indicated that PR-IP Inducer exerted two different biological activities although their inducing mechanisms seemed to be different.
