摘要
详细观察和描述了稀有鮈鲫眼发育的形态变化,并分别对视网膜发育早期神经层、色素上皮层的厚度及眼发育后期视网膜的总厚度进行了测量。结果表明:稀有鲫眼的发生始于神经胚时期形成的眼原基,与两栖、哺乳类动物不同,其眼原基是由间脑向左右伸出的对称外突实体;在尾芽期眼原基向腹侧弯曲、侧向伸长,随后开始内陷,在尾泡期形成视杯。眼原基外层与外胚层紧贴的部分将发育为视杯的内层、神经视网膜,而眼原基其余部分将分化为视杯的外层、视网膜色素层。在尾泡期之后,视网膜色素层停止有丝分裂开始形成色素颗粒,此时视网膜神经层开始分化。视网膜这两层结构在发育早期分化的有序进行可能与早期胚胎头部内空间以及附近的间充质细胞有关。从神经胚期到尾泡期,视网膜色素层厚度由42.3±0.8μm减小到4.8±0.4μm,视网膜神经层厚度从37.1±0.2μm增加到43.7±0.6μm,而从尾鳍期到孵出期视网膜总厚度从42.7±1.2μm逐渐增加到98.3±2.1μm。与所有脊椎动物一样,稀有鲫眼的视网膜分化也是按照由内向外的顺序进行,晶状体、角膜及其他结构在孵出时已基本发育完全。
Gobiocypris rarus was a new genus of danioninae from China. It had some good characteristic such as strong vitality, short mature period and breeding every year when raised in the Lab. So recently it was reguarded as an ideal experimental material. Eye morphogenesis in the Gobiocypris rarus was observed and described in detail. Retina, lens and cornea development were our emphases. Meanwhile, the thickness of the pigment epithelium layer and the neural retina from Neurula period to Tail vesicle period and the total thickness of the retina from Caudal fin period to Hatching period of Gobiocypris rarus were measured. The results indicated that the eye morphogenesis in the C, obiocypris rarus begins with the formation of optic primordia. Unlike amphibians and mammals, the optic primordia are the evaginations from the forebrain as solid masses of cells .They were communicate with the neural keel and the elliptic cells within the primordium are radially arranged. In this period mesenchyme cells are also observed ventral to the optic primordium. The optic primordia bend ventrally and elongate laterally and take on a distinctive wing-like shape in tail bud period. They had contacted with the ectoderm closely already. In tail vesicle period, the optic cup is well formed. The out layer of the optic primordia clings to the ectoderm will give rise to the neural retina whereas the other part of the optic primordia will give rise to the pigment epithelium. The neural retina will not differentiate until mitosis with- in the pigment epithelium layer stopped and pigment was synthesized after the Tail vesicle period. The orderly differentiation of the two layer of retina is probably related to the space in embryo and the mesenchyme nearby. From Neurula period to Tail vesicle period, the thickness of the pigment epithelium layer reduced evidently from 42.3±0.8μm to 4.8±0.4μm while the thickness of neural retina increased indistinctively from 37.1±0.2μm to 43.7±0.6μm. From Caudal fin period to Hatching period, the total th
出处
《水生生物学报》
CAS
CSCD
北大核心
2005年第6期607-614,共8页
Acta Hydrobiologica Sinica
基金
甘肃省自然科学基金资助(编码:YS981-A25-002)
关键词
稀有鮈鲫
眼
形态发生
视网膜
晶体
角膜
Gobiocypris rarus
Eye
Morphogenesis
Lens
Retina
Cornea
