Inception of bioluminescent symbiosis in early developmental stages of the deep-sea fish, Coelorinchus kishinouyei (Gadiformes: Macrouridae)
Inception of bioluminescent symbiosis in early developmental stages of the deep-sea fish, Coelorinchus kishinouyei (Gadiformes: Macrouridae)
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DOI：
10.1007/s10228-013-0374-7
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发表时间：
2014-01-01
影响因子：
1.2
通讯作者：
Fukui, Atsushi
中科院分区：
文献类型：
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作者：
Dunlap, Paul V.;Takami, Munehiro;Fukui, Atsushi
从近海底栖息地捕获的大型鱼类Coelorinchus kishinouyei的幼虫和幼鱼（约1000米）。1-10米以上的海底）在186至500米的深度在骏河湾，本州，日本，进行了检查的存在，发育状态，和细菌定植的鱼的内部腹光器官。这些标本的头部长度从3.6 mm到8.5 mm不等，并且都表现出从肛门周围向前扩展的外部黑色素细胞簇，这被认为表明存在内部发光器官。组织学分析显示，在所有检查标本的光器官的存在。在较小的标本中，光器官被视为与肛门附近的肠相关的小块组织;在较大的标本中，光器官逐渐向前伸长，形成由中空的指状腔室组成的豆状结构。细菌存在于一些，但不是所有的幼虫和所有的青少年的光器官室。在尚未被细菌定殖的光器官中，腔室在其整个长度上表现出大致均匀的外观。在定殖的轻器官中，细菌始终存在于腔室的最前尖端处;此外，包含由细菌定殖的腔室的细胞肿胀，并且在细菌定殖后，腔室的方向开始从前-后变为背-腹。基于luxA基因的序列分析，将定殖细菌鉴定为岸田发光杆菌。这些结果表明，光器的形成是由光器的发育过程引起的. kishinouyei开始于鱼类的浮游阶段，但细菌在发光器官的定植发生在幼虫到达近海底栖息地之后。此外，由P. kishitanii的新生光器官的定殖诱导光器官的形态发生变化。
Larvae and juveniles of the macrourid fish Coelorinchus kishinouyei, captured from the near-bottom habitat (ca. 1-10 m above the seafloor) at 186 to 500 m depth in Suruga Bay, Honshu, Japan, were examined for the presence, developmental state, and bacterial colonization of the fish's internal ventral light organ. The specimens ranged from 3.6 mm to 8.5 mm head length, and all exhibited an external cluster of melanophores expanding anteriorly from around the anus that is thought to indicate the presence of an internal light organ. Histological analysis revealed the presence of a light organ in all examined specimens. In smaller specimens, the light organ was seen as a small nub of tissue associated with the intestine near the anus; the light organ gradually elongated anteriorly in larger specimens to form a bean-shaped structure composed of hollow, finger-like chambers. Bacteria were present within the light organ chambers of some, but not all larvae and all juveniles. In light organs not yet colonized by bacteria, the chambers exhibited a generally uniform appearance over their entire length. In colonized light organs, the bacteria were consistently present at the anterior-most tips of the chambers; furthermore, cells comprising chambers colonized by bacteria were swollen, and upon bacterial colonization the orientation of the chambers began to change from anterior-posterior to dorsal-ventral. The colonizing bacteria were identified as Photobacterium kishitanii based on sequence analysis of the luxA gene. These results suggest that formation of the light organ in C. kishinouyei begins during the fish's pelagic phase, but that bacterial colonization of the light organ occurs after the larvae have reached the near-bottom habitat. Furthermore, colonization of the nascent light organ by P. kishitanii induces morphogenetic changes in the light organ.