TY - JOUR
T1 - A novel oocyte maturation arresting factor in the central nervous system of scallops inhibits serotonin-induced oocyte maturation and spawning of bivalve mollusks
AU - Tanabe, Toru
AU - Osada, Makoto
AU - Kyozuka, Keiichiro
AU - Inaba, Kazuo
AU - Kijima, Akihiro
N1 - Funding Information:
The authors thank the staffs of the Field Science Center of Tohoku University for their help in our experiment. We express our many thanks to Dr. K. Sasaki, Tohoku University, Mr. K. Matsuura, Miyagi Prefecture Fisheries Research and Development Center, Dr. Y. Kosaka, Aomori Prefectural Fisheries Research Center, Dr. T. Suzuki, Aichi Fisheries Research Institute, and Mr. M. Toba, Chiba Prefectural Fisheries Research Center, for supplying animals. This work was supported by a Grant-in-Aid for Scientific Research (15580155) from the Japanese Ministry of Education, Culture, Sports, Science, and Technology (to M.O.).
PY - 2006/7
Y1 - 2006/7
N2 - Serotonin (5-hydroxytriptamine; 5-HT) is a major neurotransmitter that triggers oocyte maturation and sequential spawning in bivalve mollusks. A proteinous and heat-labile substance that proved to be a novel inhibitor of 5-HT-induced egg release from ovarian tissue was found in the cerebral and pedal ganglia (CPG) of the scallop Patinopecten yessoensis. The same inhibitory activity was also observed in the proteinous fraction from the supernatant of hemolymph. Histological observation demonstrated that the novel inhibitor prevented 5-HT from inducing oocyte maturation in the scallop ovary and that no prostaglandin F2α (PGF2α) inhibited 5-HT-induced oocyte maturation, although PGF2α strongly prohibited 5-HT-induced egg release through the gonoduct from ovarian tissue. The novel inhibitor from the scallop CPG also prohibited 5-HT-induced oocyte maturation of other bivalve species as well as scallops. The novel inhibitor, mediated through a receptor mechanism on oocyte membranes, blocked extracellular Ca2+ uptake into oocytes, which was observed in 5-HT-induced oocyte maturation. It is suggested that the novel inhibitor with a molecular mass of 60 kDa, named oocyte maturation arresting factor, which appears to be a universal substance for bivalve species, may be transported from the CPG to the ovary via hemolymph and may prohibit 5-HT-induced oocyte maturation due to the interference of extracellular Ca2+ influx into oocytes, eventually resulting in the inhibition of spawning. On the other hand, it seems that PGF2α inhibits 5-HT-induced transport of mature eggs through the gonoduct.
AB - Serotonin (5-hydroxytriptamine; 5-HT) is a major neurotransmitter that triggers oocyte maturation and sequential spawning in bivalve mollusks. A proteinous and heat-labile substance that proved to be a novel inhibitor of 5-HT-induced egg release from ovarian tissue was found in the cerebral and pedal ganglia (CPG) of the scallop Patinopecten yessoensis. The same inhibitory activity was also observed in the proteinous fraction from the supernatant of hemolymph. Histological observation demonstrated that the novel inhibitor prevented 5-HT from inducing oocyte maturation in the scallop ovary and that no prostaglandin F2α (PGF2α) inhibited 5-HT-induced oocyte maturation, although PGF2α strongly prohibited 5-HT-induced egg release through the gonoduct from ovarian tissue. The novel inhibitor from the scallop CPG also prohibited 5-HT-induced oocyte maturation of other bivalve species as well as scallops. The novel inhibitor, mediated through a receptor mechanism on oocyte membranes, blocked extracellular Ca2+ uptake into oocytes, which was observed in 5-HT-induced oocyte maturation. It is suggested that the novel inhibitor with a molecular mass of 60 kDa, named oocyte maturation arresting factor, which appears to be a universal substance for bivalve species, may be transported from the CPG to the ovary via hemolymph and may prohibit 5-HT-induced oocyte maturation due to the interference of extracellular Ca2+ influx into oocytes, eventually resulting in the inhibition of spawning. On the other hand, it seems that PGF2α inhibits 5-HT-induced transport of mature eggs through the gonoduct.
KW - Bivalve mollusks
KW - Central nervous system
KW - Extracellular Ca influx
KW - Oocyte maturation
KW - Oocyte maturation arresting factor
KW - PGF
KW - Scallop
KW - Serotonin
KW - Spawning
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U2 - 10.1016/j.ygcen.2006.02.004
DO - 10.1016/j.ygcen.2006.02.004
M3 - Article
C2 - 16574113
AN - SCOPUS:33646763142
VL - 147
SP - 352
EP - 361
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
SN - 0016-6480
IS - 3
ER -