쥐노래미, Hexagrammos otakii의 난소발달에 다른 성 스테로이드 호르몬의 활성 변화

Abstract

We studied oocyte steroidogenesis in relation to oocyte development in the greenling, Hexagrammos otakii, a marine multiple spawner. Vitellogenic and mature oocytes were incubated in vitro in the presence or absence of <TEX>$[^3H]-17\;{\alpha}-hydroxyprogesterone$</TEX> as a precursor. The major metabolites were androgens [androstenedione <TEX>$(A)_4)$</TEX> and testosterone (T)] and estrogens [<TEX>$17\;{\beta}-estradiol\;(E_2)$</TEX> and estrone (<TEX>$E_1$</TEX>)] in vitellogenic oocytes. The metabolic rate of T was lower in 1.08 to 12-mm oocytes, while that of <TEX>$E_2$</TEX> increased with oocyte size. The endogenous productions of T, <TEX>$E_2$</TEX> and 17 <TEX>${\alpha}-hydroxy$</TEX>, 20 <TEX>${\beta}-dihydroprogesterone\;(17{\alpha}20{\beta}OHP)$</TEX> were quantified using a radioimmunoassay in the non-precursor group. The endogenous levels of T and <TEX>$E_2$</TEX> were highest in 1.08 to 12-mm oocytes and <TEX>$17{\alpha}20{\beta}OHP$</TEX> was produced only in 1.90 to 95-mm oocytes. The relationship between oocyte size and steroidogenesis showed that 1.08 to 12-mm oocytes are full vitellogenic following induction of the maturation process. Moreover, <TEX>$17{\alpha}20{\beta}OHP$</TEX> acts as a maturation inducing hormone in H. otakii.