Interactions between oocytes of different maturational stages in the carp Cyprinus carpio: effects on maturational and steroidogenic activity in vitro.
Ovarian fragments from carp which had received injections of saline (control) or carp hypophysial homogenate (primed) were incubated both alone and a cocultures of primed and control tissue in the presence of carp pituitary extract. The results showed that the cocultures were not simply the sums of separate incubations. Oocyte maturation was retarded in primed tissue but advanced in control tissue and concentrations of 17,20 beta-dihydroxy-4-pregnen-3-one (17,20 beta P) in the medium were significantly lower than that expected from separate incubations. The results indicate that local factors may act to synchronize oocyte maturation throughout the ovary to enable spawning of the maximum number of eggs.
Kime
D E
DE
Department of Animal Biology, The University, Sheffield, United Kingdom.
Epler
P
P
Bieniarz
K
K
Motyka
K
K
Mikolajczyk
T
T
D000818:Animals; D002347:Carps / Q000502:physiology*; D003530:Cyprinidae / Q000502:physiology*; D005260:Female; D006908:Hydroxyprogesterones / Q000032:analysis / Q000096:biosynthesis*; D009865:Oocytes / Q000254:growth & development*
D006908:Hydroxyprogesterones; C007433:17,20-dihydroxy-4-pregnen-3-one