摘要
唇皮层小泡1-4层,在光镜和透射电镜下均具5种形态,由外及内,小泡内颗粒直径逐渐减少。在H.E染 色中,动物极低纬度区和精孔器附近的卵膜和质膜之间,具少量均匀的着色非常深的紫色斑点,与Ⅰ型皮层小泡内 容物形态结构相似,在透射电镜下,这些斑点和卵膜、质膜有明显的界限,其外没有包被膜相结构,我们称之皮层反 应引发斑,这是在鱼类受精卵中发现的一个新的结构。扫描电镜下,引发斑成絮状。引发斑对皮层反应的引发具 有重要作用。皮层反应可分为潜伏期、始发期、高潮期、衰退期四个时期,潜伏期没有皮层反应发生,始发期只是位 于受精卵外围的少量皮层小泡释放,高潮期为多个皮层小泡相互融合形成一个大的泡状体,泡状体再与质膜接触、 融合后,随后破裂,释放内容物,可分为两个阶段,衰退期释放Ⅴ型皮层小泡和其他残存的皮层小泡以及未完全降 解卵黄颗粒碎屑;皮层反应是由Ⅰ型皮层小泡和引发斑诱导的爆发性的链式反应,卵子外侧的皮层反应可以诱导 内侧皮层反应。皮层反应有两个起始区域,在受精后35s开始于动物极低纬度区,稍后出现在精孔器前庭附近,随 后在这两个始发区向四周扩散,并在前庭以外的区域愈合、打通。皮层小泡分批多次释放,质膜多次重组。精子入 卵位点附近没有皮层小泡,不发生皮层反应,这提示皮层反应对鱼类多精受精的抑制效应有限。
There are 1 to 4 rows and five types of cortical alveoli in the cortex of the pallas, Hemibarbus labeo egg. From inner to outer of the cortex, the diameter of cortical alveoli decreases gradually. We find a new structure named solicitation speckle at low latitude of animal polar and near micropylar apparatus between envelope of ovum and plasma membrane, in zygote of fish. The solicitation speckle is very purple in H. E, that is similar to type Ⅰ of cortical alveoli. In TEM, the solicitation speckle has not obvious bourn with envelope of ovum and plasma membrane, and no membrane around the solicitation speckle too. In SEM, the solicitation speckle looks as garrulous. During cortical reaction, the solicitation speckle plays very important initiative function. About 35s after fertilization, cortical alveolus begin to discharge from the low-latitudes of the animal hemisphere, later, the same thing happens in the near of micropylar apparatus, and then cortical reaction extends to the animal hemisphere and the veg- etal hemisphere. Cortical reaction comprises latent period, developmental period, climactic period and declining period. In latent period, no cortical reaction, in developmental period, a few cortical alveolus discharge outer of the cortex, in climactic period, many cortical alveolus discharge, before discharging several cortical alveolus fuse into a big vesicle, and in declining period, type V of cortical alveoli inner of the cortex discharges. 5min after fertilization, cortical alveoli has discharged entirely in the animal hemisphere, the residual cortical alveolus will entirely discharge in 8min. We think cortical reaction is a fulminic chain reaction abducted by solicitation speckle and type Ⅰ of cortical alveoli, the outer cortical reaction can accelerate the inner cortical reaction. While cortical alveoli discharges in batches, the plasma membrane has been reorganized time after time. No cortical alveoli below the micropylar tube where sperm enter into, this suggests it is finite that the cortical reaction prevents polyspermy.
出处
《水生生物学报》
CAS
CSCD
北大核心
2005年第5期479-487,共9页
Acta Hydrobiologica Sinica
基金
重庆市科委攻关项目(No.2001-6630)
三峡库区生态环境教育部重点实验室基金(No.03121)
东南大学基础医学院青年科学基金(No.2004A06)资助
关键词
唇[鱼骨]
皮层小泡
皮层反应
引发斑
引发机制
Hemibarbus labeo
Cortical alveoli
Cortical reaction
Solicitation speckle
Solicitation mechanism