养殖中华鲟性腺发生与分化的组织学研究

用组织切片方法研究人工繁育中华鲟的性腺发生及两性分化过程。中华鲟出膜后3d，原始生殖细胞以单细胞的形式存在于肾管区腹下方。出膜后11d，生殖褶形成，到2月龄和7月龄时，性腺中分别出现血管和脂肪组织，直到8月龄性腺均处于两性未分化状态，划分为0期。9月龄(体重0．6～1．1kg)，性腺出现组织学水平上的两性分化，性腺划入I期。I期性腺中，精(卵)原细胞进行有丝分裂。以初级精(卵)母细胞出现作为Ⅱ期开始的标志，精巢和卵巢分别于1．8～2．2年龄(1.55～5．6kg)和2．5～3．0年龄(3．1～8．2kg)进入Ⅱ期。3年龄以后，性腺发育分化陆续达到肉眼可分辨性别的程度，5～5．6年龄(18～35．5kg)时，所有的性腺能肉眼区分雌雄，但精巢和卵巢仍都处于Ⅱ期，其中卵母细胞的卵径为60～240μm。

Histological studies on gonadal origin and differentiation of cultured Acipenser sinensis

Gonadal origin and gonadal different iation of cultured Chinese sturgeon, Acipenser sinensis were studied using light microscope. The primordial germ cell( PGC) was first seen below the nephridium area on the third day after hatching, and by the 11th day the primordial gonad, genital fo ld formed. Later, with the gonad growing, the blood vessel appeared in it when f ish was 2 months old and the adipose fatty tissue appeared by the age of 7 months. According to Hochleithner &Gessner( 1999) , we classif ied stage 0 of gonad development of this f ish as the stage with no histological sex differentiation. Histological sex differentiation of the gonads was completed by the age of 9 months( 0. 6 - 1. 1kg B. W. ) , and the gonads entered stage . , during which mitosis of the spermatogonia and oogonia occurred. With the primary spermatocytes or oocytes appearing , the testes or ovaries reached stage ? when f ish were 1. 8- 2. 2 years old( 1. 55- 5. 6kg B. W. ) or 2. 5- 3 years old( 3. 1- 8. 2 kg B. W. ) respectively. After the age of 3 years, the gonads, in succession, became what could be sexed by gross examination, and at the age of 5- 5. 6 years( 18- 35. 5kg B. W. ) , all of the gonads could be sexed by gross examination and st ill remained in stage ? , with the diameter of oocytes of 60- 240Lm.