STRUCTURAL ORGANIZATION, TRANSFER AND BIOLOGICAL FATE OF ENDOSYMBIOTIC BACTERIA IN GUTLESS OLIGOCHAETES
STRUCTURAL ORGANIZATION, TRANSFER AND BIOLOGICAL FATE OF ENDOSYMBIOTIC BACTERIA IN GUTLESS OLIGOCHAETES
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DOI：
10.1007/bf00392801
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发表时间：
1987-01-01
期刊：
影响因子：
2.4
通讯作者：
LANGHELD, C
中科院分区：
文献类型：
--
作者：
GIERE, O;LANGHELD, C
从大小和结构的差异来看，在百慕大的无胆寡毛菌白皮Phallodrilus和P. planus中似乎有两种革兰氏阴性菌。胞外细菌沿蠕虫身体长度的非随机、分化和一致的分布模式强调了细菌定植的调节性质。这也从对寄主世代之间细菌转移的研究中得出：寡毛纲的例外是，卵单独存放在粘性粘液鞘中，而不是一起存放在茧中。它们在产卵时立即被感染，显然是由于靠近雌性毛孔的生殖垫中的大量“储存”细菌侵入。在个体形成过程中，在细胞外、活性细菌和被表皮细胞包裹在液泡中的细胞内裂解形式之间建立了平衡。在早期发育阶段，溶解细菌占主导地位，但较老的蠕虫主要在其角质层下藏有细胞外原核生物。厚的表皮/角质层复合体在规则的区域内分化，并在较深的层内逐渐包裹和消化细菌。这是关于生活在动物体内的“硫化物生物群落”内共生细菌的转移和生物命运的第一个结果。
From differences in size and structure, it appears there are two species of gram-negative bacteria in the gutless oligochaetes Phallodrilus leukodermatus and P. planus from Bermuda. A non-random, differentiated and consistent distribution pattern of the extracellular bacteria along the length of the worm''s body underlines the regulated nature of the bacterial colonization. This emerges also from studies on the transfer of the bacteria between host generations: exceptional for oligochaetes, eggs are deposited singly in a sticky mucus sheath and not together in a cocoon. They become infected immediately at oviposition, apparently by intrusion from large ''stores'' of bacteria in a genital pad abutting the female pores. During ontogenesis, a balance is established between extracellular, active bacteria and intracellular lytic forms enclosed in vacuoles by the epidermial cells. In early developmental stages, lytic bacteria prevail, but older worms harbour mainly extracellular prokaryotes underneath their cuticle. The thick epidermis/cuticle complex is differentiated in regular zones with a progressive trend towards enclosing and digesting bacteria intracellularly in the deeper layers. These are the first results on the transfer and biological fate of endosymbiotic bacteria living in animals from ''sulfide biotopes''.