Differences between colonial and solitary corals

在群体珊瑚中，等基因嫁接总是融合，而在孤立珊瑚中，等基因个体在接触时不会融合。虽然群落珊瑚和独居珊瑚之间的差异具有重要的生态学意义，但对导致独居珊瑚和群落珊瑚之间生理和形态差异的机制的研究却很少。本研究旨在阐明产生孤立珊瑚和殖民地珊瑚之间差异的机制。为了研究孤独珊瑚在发育早期是否表现出群体特征，我们观察了从孤独珊瑚真菌属（Fungia spp.）的组织片段中再生的幼体珊瑚虫的形态发生模式，并利用从同一个体的组织中再生的克隆珊瑚虫进行了接触实验。当一个组织碎片再生两个以上的息肉时，它们在5-13个月的观察期内保持殖民地形态。当再生的息肉来自同一个体时，当我们接触到更多的息肉时，它们融合了。在一个病例中，融合发生在茎部而不是椎间盘。一些群体形式分离成单独的珊瑚虫，而另一些则通过融合而变成孤立的形式，即触手环和嘴的融合。目前的研究结果表明，孤珊瑚如Fungia在再生的早期阶段表现出殖民地特征。有人认为，真菌从盘片中获得孤独的性状。由原生水螅（沉降的扁平藻）产生的水螅和由成年水螅枝尖再生的水螅的生长形态不同。在9个月的观察期间，从初生水螅体衍生的幼菌落在一个群体的中心区域至少形成一个分支，而从成年枝尖端（3-5毫米长）再生的菌落从未形成分支。结果表明，随着年龄的增长，达米角蚁群落的枝发生率逐渐降低。这一发现为在分子水平上分析珊瑚枝的形成机制开辟了道路。我们尝试用组织相容性试验和分子标记来区分珊瑚的克隆。我们发现微卫星标记PV5和PV7在一定程度上具有多态性，但无法检测兄弟姐妹之间或亲本与子代之间的遗传差异。结果表明，ITS1序列在damicornis中具有高度的差异性，可用于珊瑚种群克隆结构的研究。少

In colonial corals, isografts invariably fuse, while, in solitary corals, isogeneic individuals do not fuse when they are brought into contact. Although the differences between colonial and solitary modes are ecologically important, few researches have been conducted on the mechanisms that cause physiological and morphological differences between solitary and colonial corals. The present study aimed to elucidate the mechanisms that produce the differences between solitary and colonial corals.To investigate whether solitary corals show colonial characters at early stages of development, we observed morphogenetic patterns of young polyps regenerated from tissue fragments of solitary corals Fungia spp. and did contact experiments using clonal polyps regenerated from tissues of the same individuals. When more than two polyps were regenerated from a tissue fragment, they remained as colonial form for 5-13 months observation period. When regenerated polyps derived from the same individual we … More re brought into contact, they fused. In one case, fusion occurred at stalk but not at disc. Some colonial forms separated into individual polyps while others changed to solitary form by integration, that is, fusion of tentacular rings and mouths. The present results suggest that solitary corals like Fungia showed colonial characters at early stages of regeneration. It has been suggested that Fungia acquire solitary characters when they from discs.Colonies of Pocillopora damicornis derived from primary polyps (settled planulae) and those regenerated from branch tips of adult colonies assumed different growth forms. Young colonies derived from primary polyps formed at least one branch from the central region of a colony, while colonies regenerated from adult branch tips(3-5 mm long) never formed branches during the nine months observation period. The results suggest that the rate of branch origination of P.damicornis colonies decreases with age. This Finding may open the way to analyze the mechanism of branch formation in corals at molecular level.We attempted to distinguish clones of a coral Pocillopora damicornis using histocompatibility assay and molecular markers. We found that microsatelite markers PV5 and PV7 were polymorphic to some extent but failed to detect genetic differences between siblings or between parent and offspring. We found that ITS1 sequences are highly variable in P.damicornis and pan be applied to studies on clonal structure within populations of the coral. Less