Holmes S D, Fairweather I
Parasitology. 1982 Oct;85 (Pt 2):237-50. doi: 10.1017/s0031182000055219.
The fine structure and histochemistry of the envelopes surrounding the mature oncosphere of Hymenolepis diminuta have been investigated by transmission electron microscopy and light microscope observations of JB-4 embedded material. The fate of these envelopes during the hatching sequence in vitro has been followed by phase-contrast and scanning electron microscopy. Hatching is considered to comprise 4 stages. Stage 1 involves the mechanical breakage and removal of the shell and the outer cytoplasmic layer of the inner envelope; Stage 2 the activation of the oncosphere and the swelling of the gelatinous layer of the inner envelope; and Stage 3 the digestion and rupture of the embryophore. This is accomplished both by secretions from the penetration gland and by the action of external digestive enzymes, together with hook activity. Trypsin is more effective than amylase in digesting the embryophore. Stage 4 involves the enzymatic weakening of the gelatinous layer which helps the oncosphere to tear itself free with its hooks. Amylase is more effective than trypsin in attacking the gelatinous layer. On emergence from the gelatinous layer, the oncosphere is still enveloped by the 'oncospheral membrane', although this covering is soon lost. Once activated, the oncosphere is capable of completing the hatching sequence by itself, without the addition of enzymes. This process is a lengthy one, however, taking up to 2 h, and the expenditure of its glandular and energy reserves makes successful gut penetration by the oncosphere unlikely.
通过对JB - 4包埋材料的透射电子显微镜和光学显微镜观察，研究了微小膜壳绦虫成熟六钩蚴周围包膜的精细结构和组织化学。利用相差显微镜和扫描电子显微镜追踪了这些包膜在体外孵化过程中的变化。孵化过程分为4个阶段。第1阶段包括外壳和内包膜外层细胞质层的机械破损和去除；第2阶段是六钩蚴的激活和内包膜凝胶层的肿胀；第3阶段是胚膜的消化和破裂。这是通过穿透腺的分泌物、外部消化酶的作用以及钩的活动共同完成的。在消化胚膜方面，胰蛋白酶比淀粉酶更有效。第4阶段涉及凝胶层的酶解弱化，这有助于六钩蚴用其钩挣脱。在攻击凝胶层方面，淀粉酶比胰蛋白酶更有效。从凝胶层出来后，六钩蚴仍被“六钩蚴膜”包裹，不过这种覆盖很快就会消失。一旦被激活，六钩蚴能够自行完成孵化过程，无需添加酶。然而，这个过程很长，需要长达2小时，而且其腺体和能量储备的消耗使得六钩蚴成功穿透肠道的可能性不大。
