. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 10 15min Time FIGURE 5. Elution pattern of Spisula factor purified by high performance liquid chromatography. Conentrated sample of the WHO fraction obtained from Dowex 1-8X column was applied to a Water Radial Pak column, eluted with M NH4H2PO4 in 10% aqueous ethanol, pH , at a flow rate of 2 ml/min. effectiveness of cAMP versus cGMP. In Spisula oocytes dbcAMP was a very potent inhibitor of GVBD when induced with sperm or serotonin. In Chaetopterus, dbcGMP was the more potent suppressor of GVBD. It was reported
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 10 15min Time FIGURE 5. Elution pattern of Spisula factor purified by high performance liquid chromatography. Conentrated sample of the WHO fraction obtained from Dowex 1-8X column was applied to a Water Radial Pak column, eluted with M NH4H2PO4 in 10% aqueous ethanol, pH , at a flow rate of 2 ml/min. effectiveness of cAMP versus cGMP. In Spisula oocytes dbcAMP was a very potent inhibitor of GVBD when induced with sperm or serotonin. In Chaetopterus, dbcGMP was the more potent suppressor of GVBD. It was reported that both dbcAMP and dbcGMP can arrest mammalian oocytes at the dictyate stage except that the suppressive activity of dbcAMP was more pronounced than dbcGMP (Hubbard and Terranova, 1982). dbcGMP may exert its inhibitory effects through the cumulus cells, while dbcAMP appears to act directly on the oocytes (Hubbard and Terranova, 1982). The observed variation in sensitivity of oocytes of different species to dbcAMP and dbcGMP deserves further attention. It was demonstrated that the Spisula factor alone blocked GVBD in Spisula and Chaetopterus oocytes. Inhibition is induced only when combined with dbcAMP in mouse oocytes. The present results suggest that the Spisula factor may be an important meiotic arresting substance. Experiments are being undertaken to determine the chemical structure of the Spisula factor. An inhibitor of mouse oocyte maturation was demonstrated to be present in porcine follicular fluid which acts synergistically with dbcAMP (Downs and Eppig, 1984). This compound was identified as hypoxanthine (Downs et ai, 1985). The Spisula factor can be separated from hypoxanthine by chromatography on Dowex 1-8X column and by reversed phase HPLC. GVBD can be induced in Spisula oocytes with sperm, KC1, and serotonin (Allen, 1953; Hirai et ai, 1984). Hirai et al (1984) demonstrated that Spisula oocytes treated with KC1 or serotonin produced maturation promoting fator (MPF)
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
