ACTION OF CMF (CELOMIC MATURATION FACTOR) ON OOCYTES OF THE POLYCHAETE ARENICOLA-MARINA (L.)

Oocyte maturation in the lugworm Arenicola marina is controlled by two hormonal steps: a prostomial maturation hormone and a coelomic matura tion factor (CMF). Oocyte maturation and spawning follows release of t he maturation hormone from the prostomium and the appearance of CMF ac tivity within the coelomic fluid. In this study, injection of female p rostomial homogenate into gravid females induced the production of CMF after approximately 1 to 2 h. Once induced, CMF activity remained for 1 to 4 h. Titres of CMF assayed in vitro between females also varied. CMF in some females induced 100% of oocytes to mature, whereas CMF re moved from others induced only about 30% maturation. Oocytes required an exposure time of approximately 20 min to CMF before maturation is a ble to proceed independently. Optimal CMF activity in vitro was observ ed at temperatures at or below 10 degrees C. CMF has already been show n to be thermolabile and have a molecular mass greater than 10 kDa. CM F is shown here to be trypsin sensitive and to have a molecular mass o f greater than 30 kDa, suggesting a proteinaceous nature. (C) 1998 Wil ey-Liss, Inc.