Foran D
Department of Biology, University of Michigan, Ann Arbor 48109.
J Exp Zool. 1991 Jul;259(1):1-8. doi: 10.1002/jez.1402590102.
The myctophids and stomiiforms represent two common groups of luminous fishes, but the source of luminescence in these animals has remained undetermined. In this study, labeled luciferase gene fragments from luminous marine bacteria were used to probe DNA isolated from specific fish tissues. A positive signal was obtained from skin DNA in all luminous fishes examined, whereas muscle DNA gave a weaker signal and brain DNA was negative. This observation is consistent with luminous bacteria acting as the light source in myctophids and stomiiforms and argues against the genes necessary for luminescence residing on the fish chromosomes. To confirm the location of this signal, a bacterial probe was hybridized in situ to sections of a stomiiform. A strong signal was generated directly over specific regions of the fish light organs, whereas no signal was found over other internal or epidermal tissues of the fish. Taken together, these data provide the first indication that luminous bacterial symbionts exist in myctophids and stomiiforms and that these symbionts account for luminescence in these fishes.
灯笼鱼和巨口鱼是两类常见的发光鱼类，但这些动物发光的来源尚未确定。在本研究中，用来自发光海洋细菌的标记荧光素酶基因片段探测从特定鱼类组织中分离出的DNA。在所检测的所有发光鱼类中，从皮肤DNA获得了阳性信号，而肌肉DNA的信号较弱，脑DNA为阴性。这一观察结果与发光细菌作为灯笼鱼和巨口鱼的光源一致，也反驳了发光所需基因位于鱼类染色体上的观点。为了确认该信号的位置，将细菌探针原位杂交到一条巨口鱼的切片上。在鱼的发光器官的特定区域直接产生了强烈信号，而在鱼的其他内部或表皮组织上未发现信号。综上所述，这些数据首次表明灯笼鱼和巨口鱼中存在发光细菌共生体，并且这些共生体是这些鱼类发光的原因。
