Symbiosis between southern dumpling squid, Euprymna tasmanica (Cephalopoda: Sepiolidae), and its luminescent symbiont, the bacterium Vibrio fischeri, provides an experimentally tractable system to examine interactions between the eukaryotic host and its bacterial partner. Luminescence emitted by the symbiotic bacteria provides light for the squid in a behavior termed "counter-illumination," which allows the squid to mask its shadow amidst downwelling moonlight. Although this association is beneficial, light generated from the bacteria requires large quantities of oxygen to maintain this energy-consuming reaction. Therefore, we examined the vascular network within the light organ of juveniles of E. tasmanica with and without V. fischeri. Vessel type, diameter, and location of vessels were measured. Although differences between symbiotic and aposymbiotic squid demonstrated that the presence of V. fischeri does not significantly influence the extent of vascular branching at early stages of symbiotic development, these finding do provide an atlas of blood vessel distribution in the organ. Thus, these results provide a framework to understand how beneficial bacteria influence the development of a eukaryotic closed vascular network and provide insight to the evolutionary developmental dynamics that form during mutualistic interactions.

中文翻译：

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Euprymna tasmanica (Cephalopoda: Sepiolidae) 的细菌发光器官中的血管结构

南方饺子鱿鱼 Euprymna tasmanica（Cephalopoda：Sepiolidae）与其发光的共生体 Vibrio fischeri 之间的共生提供了一个实验上易于处理的系统来检查真核宿主与其细菌伙伴之间的相互作用。共生细菌发出的光以一种被称为“逆光”的行为为鱿鱼提供光，这使得鱿鱼可以在下降的月光中掩盖它的阴影。尽管这种关联是有益的，但细菌产生的光需要大量氧气来维持这种耗能反应。因此，我们检查了带有和不带有 V. fischeri 的 E. tasmanica 幼鱼的光器官内的血管网络。测量血管类型、直径和血管位置。尽管共生和非共生鱿鱼之间的差异表明，费氏弧菌的存在不会显着影响共生发育早期血管分支的程度，但这些发现确实提供了器官中血管分布的图谱。因此，这些结果提供了一个框架，以了解有益细菌如何影响真核闭合血管网络的发育，并提供对互惠相互作用过程中形成的进化发育动力学的见解。