Abstract
It is well known that after mixing gametes of two mating types of the green alga Chlamydomonas reinhardtii, intracellular cAMP concentration increases within 1 min, and zygotes are formed within 10 min. We have shown that within 10 min after the mixing, zys genes are expressed. In the present study, we isolated and determined the sequence for a zys3 genomic clone. Comparing this 5′ upstream region with those of zys1B and zys4, we detected putative AP-1-related elements including cyclic AMP responsive elements in three upstream gene regions.