银盾革蜱的中肠上皮变化与血餐消化

用光学显微镜及电子显微镜对不同生理状况下银盾革蜱Dermacentor niveus Neumann雌虫中肠上皮及血餐消化进行了研究.饿蜱的中肠只由一种干细胞组成,脂滴作为饿蜱营养的贮藏形式.非滞育蜱消化分三个阶段,即第一连续消化阶段,减慢消化阶段及第二连续消化阶段.吸血后中肠上皮共观察到四种细胞类型,即替代细胞、分泌细胞、消化细胞及卵赞原细胞.滞育蜱第一连续消化阶段延长.饱血后60天到120天,消化作用几近停止,为停滞消化阶段.卵黄原细胞的超微结构有明显改变.滞育解除后,开始进行减慢消化阶段及第二连续消化阶段.

CHANGES OF MIDGUT EPITHELIUM AND BLOODMEAL DIGESTION IN THE TICK DERMACENTOR NIVEUS NEUMANN

The midgut epithelium and bloodmeal digestion in Dermacemor niveus Neumann at different physiological states were studied with light and electron microscopes. The results are as follows. Only one cell type, the stem cells, was found in the midgut of unfed female ticks. Lipid inclusions appeared to be the reserve of food. Digestion in non-diapausing female ticks occurred in three distinct phases, namely, the first continuous digestion, the reduced digestion and the, second continuous digestion. Four types of cells were observed after feeding; They include the replacement cells, the excretory cells, the digestive cells and vitellogenic cells. The first continuous digestion was prolonged in diapausing females. From the 60th to 120th days after detachment digestion almost stopped, and thus it is designiated as the stagnated digestion, The ultrastructure of the vitellogenic cells underwent distinct changes. The reduced digestion and second continuous digestion would occur after the termination of diapause.