Morphological development of the gonads in zebrafish
Morphological development of the gonads in zebrafish
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DOI：
10.1046/j.1095-8649.2003.00074.x
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发表时间：
2003-04-01
影响因子：
2
通讯作者：
Segner, H
中科院分区：
文献类型：
--
作者：
Maack, G;Segner, H
采用光学显微镜观察斑马鱼性腺发育过程，以检验性腺组织学作为内分泌活性物质危害性评价指标的适用性。受精后2周龄，原始生殖细胞在体腔内位于背尾侧。在产后4周，大多数鱼（86%）拥有配对的性腺与减数分裂生殖细胞：这些性腺代表推定卵巢。在第5周，87%的鱼检查有卵巢与核仁周围的卵母细胞。雌性斑马鱼性腺进一步发育至第11周，其特征是性腺大小以及核仁周卵母细胞的数量和大小增加。从第5周开始，一些鱼的性腺形态发生了变化，包括卵母细胞的数量和大小减少，嗜碱性增强和卵母细胞的不规则形状，最后它们退化成残留体。随着卵母细胞数量的减少，基质细胞增多，并向性腺基质浸润。在几个7周龄的斑马鱼性腺形态改变，生殖细胞的数量增加，排列在囊肿样组出现。这些性腺被解释为假定的睾丸。在一条鱼的32个人检查，精母细胞被检测到，除了生殖细胞。在随后的几周内，显示早期睾丸和精原细胞的鱼的百分比。精母细胞和精子细胞增加，并达到40%，在11周PF。从第5周PF起发生在一些人的性腺改变的顺序被解释为反映向睾丸的过渡的雌核发育卵巢。所描述的发育模式确定斑马鱼是一种幼年雌雄同体。这项研究的结果是相关的性腺组织病理学的使用作为内分泌干扰试验的终点，特别是为了避免在斑马鱼的“两性性腺”的错误诊断。(C)2003年，不列颠群岛渔业协会。
Gonadogenesis of zebrafish Danio rerio was investigated by means of light microscopy to test the suitability of gonad histology as all endpoint in hazard assessment of endocrine-active compounds. At age 2 weeks post-fertilization (pf), primordial germ cells were found ill a dorsocaudal position in the body cavity. At 4 weeks pf, the majority of the fish (86%) possessed paired gonads with meiotic germ cells: these gonads represented presumptive ovaries. At week 5 pf 87% of the fish examined had ovaries with perinucleolar oocytes. Further development of the gonads in female zebrafish up to week 11 pf was characterized by an increase in gonad size as well as in the number and size of perinucleolar oocytes. Starting with week 5, some fish showed alterations of gonad morphology, including a decrease in the number and size of the oocytes, an enhanced basophilia and irregular shape of the oocytes, and finally their degeneration into residual bodies. With the decline in oocyte number, stromal cells became more numerous and they infiltrated the gonadal matrix. In several 7 week-old zebrafish with altered gonadal morphology, enhanced numbers of gonial cells arranged in cyst-like groups appeared. These gonads were interpreted as presumptive testes. In one fish out of 32 individuals examined, spermatocytes were detected, in addition to the gonial cells. During the subsequent weeks, the percentage of fish showing early testes with spermatogonia. spermatocytes and spermatids increased and reached 40% at 11 weeks pf. The sequence of gonadal alterations taking place in some of the individuals from week 5 pf onwards was interpreted to reflect the transition of protogynic ovaries into testes. The developmental pattern described identifies zebrafish to be a juvenile hermaphrodite. The results of this study are of relevance for the use of gonadal histopathology as endpoint in endocrine disruption testing, particularly in order to avoid false diagnoses of 'intersex gonads' in zebrafish. (C) 2003 The Fisheries Society of the British Isles.