半滑舌鰨养殖群体雌雄比例与自然性逆转率

利用半滑舌鳎（Cynoglossus semilaevis Günther）性别连锁微卫星标记scaffold1128₃43和性腺组织切片的方法,研究半滑舌鳎8个普通家系和养殖场雄性亲鱼遗传性别与性逆转情况。首先,8个普通家系（28、30、38、39、40、44、57、69）遗传性别检测结果显示,遗传雌性比例最低为39家系（37.93%）,最高为38家系和40家系（55.00%）。对其中4个家系（28、39、44、57）的两次遗传性别比例检测结果对比发现,家系间遗传雌性比例存在差异。其次,对4个家系（28、39、44、57）和养殖场雄性亲鱼的遗传与表型性别鉴定结果表明,不同家系表型雌鱼比例为18.75%⁴6.88%,低于各家系的遗传雌性比例,不同家系间自然性逆转率存在显著性差异（P<0.05）。研究还发现,繁育场所用的普通雄性亲鱼中平均有28.42%的伪雄鱼。本研究结果表明,自然性逆转现象在半滑舌鳎养殖群体中普遍存在,半滑舌鳎不同家系的表型雌鱼比例存在显著差异,这为培育半滑舌鳎高雌性苗种提供了理论依据。

Analysis of the female ratio and natural sexual reversal ratio in cultured half-smooth tongue sole families

We detected the genetic sex and the occurrence of sex reversal in eight normal families and their male parents in the half-smooth tongue sole (Cynoglossus semilaevis Günther) using the SSR female-specific marker scaffold 1128_343 and a gonad slice. The proportion of females in eight normal families (28, 30, 38, 39, 40, 44, 57, and 69) ranged from 37.93 to 55.00%. The genetic sex of four of the eight normal families (28, 39, 44, 57) was detected twice, and the proportion of femalesdid not exibit significant difference between two tests (P>0.05). We detected both the genetic sex and physiological sex in four of the eight normal families (28, 39, 44, and 57) and in all the male parents. The proportion of physiological females ranged from 18.75%−46.88% among the four families, and was lower than the proportion of genetic females. Our results suggest there are inter-family differences in the proportion of females undergoing sex-reversal. The present study also suggests that a significant number of male parent fishes (28.42%) are neo-males. Our results suggest that sex reversal is a natural phenomenon in the half-smooth tongue sole breeding population. Furthermore, we reveal the pedigrees of different physiological spawner ratio have significant differences. Our observations provide a theoretical basis for developing methods to culturing families that have a high proportion of female larvae.