LEISHMANIA IN PHLEBOTOMID SANDFLIES .1. MODIFICATIONS OF FLAGELLUM ASSOCIATED WITH ATTACHMENT TO MID-GUT AND ESOPHAGEAL VALVE OF SANDFLY
LEISHMANIA IN PHLEBOTOMID SANDFLIES .1. MODIFICATIONS OF FLAGELLUM ASSOCIATED WITH ATTACHMENT TO MID-GUT AND ESOPHAGEAL VALVE OF SANDFLY
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DOI：
10.1098/rspb.1974.0085
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发表时间：
1974-01-01
期刊：
影响因子：
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通讯作者：
ASHFORD, RW
中科院分区：
文献类型：
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作者：
KILLICKKENDRICK, R;MOLYNEUX, DH;ASHFORD, RW
用电镜观察了墨西哥利什曼原虫亚马逊亚种前鞭毛体在实验感染的长须沙蝇肠道内的附着方式。在感染性血餐后的第二天和第三天，寄生虫在餐内繁殖，这是包裹在围食膜在后中肠;一些nectomonads在外围的餐成为嵌入在膜，这阻止了寄生虫和肠壁的微绒毛之间的接触。当消化的血粉在第二或第三天进入后肠时，中肠壁的一些细胞脱落到管腔中，然后微绒毛的高度降低，占据上皮表面的较小面积。在第四和第五天，作为微绒毛延长和表面积增加，寄生虫成为连接到后中肠的微绒毛插入它们之间的鞭毛;没有观察到连接复合体之间的鞭毛的nectomonads和微绒毛。一些独立寄生虫的鞭毛变得非常肿胀，膜轮开始在鞭毛鞘中形成。在贲门部，前鞭毛体由细长的吻单胞体转变为肥胖的触单胞体。后一种形式是紧密的，相互挤压，并对贲门的微绒毛，但不附着在这部分肠道。然而，在消化道衬里变成角质层的食管瓣膜中，许多触单胞菌在其鞭毛鞘内形成半桥粒，并附着于瓣膜的角质层衬里和食管的后部。这些模式的附件进行了比较与其他锥虫，并讨论了它们可能的重要性，在建立感染的前站的白蛉和传播咬。
The modes of attachment of promastigotes ofLeishmania mexicana amazonensisin the gut of experimentally infected sandflies (Lutzomyia longipalpis) were examined with the electron microscope. During the second and third days after an infective blood meal, parasites multiplied inside the meal, which was encased in a peritrophic membrane in the posterior mid-gut; some nectomonads at the periphery of the meal became embedded in the membrane, which prevented contact between the parasites and the microvilli of the wall of the gut. As the digested blood meal passed into the hind-gut on the second or third day, some of the cells of the wall of the mid-gut were shed into the lumen, and the microvilli were then reduced in height and occupied a smaller area of the epithelial surface. On the fourth and fifth days, as the microvilli lengthened and increased in surface area, the parasites became attached to the microvilli of the posterior mid-gut by inserting their flagella between them; no junctional complexes were observed between the flagella of nectomonads and microvilli. The flagella of some unattached parasites became greatly swollen and membranous whorls began to form in the flagellar sheath. In the cardia, the promastigotes transformed from slender nectomonads to fat haptomonads. The latter forms were tightly, packed against one another and against the microvilli of the cardia, but were not attached to this part of the gut. However, in the oesophageal valve where the lining of the alimentary canal changed into cuticle, many haptomonads formed hemidesmosomes within their flagellar sheaths and became attached to the cuticular lining of the valve and the posterior part of the oesophagus. These modes of attachment are compared with those of other trypanosomatids, and their possible importance in the establishment of infections in the anterior station of sandflies and transmission by bite is discussed.