Tests of hypotheses of vertical transmission and competitive exclusion for particular resource-exchange mutualisms require assessments of the number and identity of partners. Unicellular green algae form a symbiosis with embryos of the northeastern yellow spotted salamander Ambystoma maculatum. The extent to which the composition of egg mass-associated taxa depends on temporal or spatial factors is unknown and the discovery of an endosymbiotic component to this symbiosis has increased the importance of knowing the specificity of the association. We assessed the diversity and relative abundance of algal and other unicellular eukaryotes in egg masses by subjecting DNA harvested from cells in egg capsules or water from breeding habitat to 18S amplicon sequencing. A nested sampling regime for two breeding seasons allowed comparisons among capsules within egg masses, among egg masses in ponds, between breeding locales, between pond water and capsule fluid, and between years. Based upon 4.33 X10⁶ reads, we found no evidence inside fifty-eight egg capsules of algal lineages outside the Oophila clade and report that, whereas non-algal eukaryotic sequence diversity was low, cercozoan protists and chytridomycete fungi were sometimes abundant. There were weak or inconsistent egg mass, year or locale effects, but there was a very strong localization effect, indicating that capsules are rarefied spaces for eukaryotic aquatic taxa. This work provides a foundation for comparing microbial community structure within and among egg masses across the geographic range of the host.

中文翻译：

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ophil是在tax的卵形团的三类分类的真核微生物组内单系的

对特定资源交换共存主义的垂直传播和竞争排斥的假设的检验需要评估伙伴的数量和身份。单细胞绿藻形成与东北黄色斑点蝾螈胚胎共生Ambystoma maculatum。鸡蛋质量相关分类单元的组成在多大程度上取决于时间或空间因素，这种共生的内共生成分的发现增加了了解这种关联的特异性的重要性。我们通过对从卵囊中的细胞或繁殖生境的水中收获的DNA进行18S扩增子测序，评估了卵团中藻类和其他单细胞真核生物的多样性和相对丰度。嵌套的采样制度可以在两个繁殖季节进行比较，从而可以比较卵团内的囊之间，池塘中卵团之间，繁殖地点之间，池塘水和囊液之间以及年份之间的比较。根据4.33 X10 ^6的读数，我们没有发现证据表明在第58层藻类谱系中有58个卵囊内有证据卵圆卵菌进化枝并报告说，尽管非藻类真核生物序列多样性低，但尾生动物的原生生物和乳糜菌真菌有时很多。卵量，年度或地点影响较弱或不一致，但定位作用非常强，表明胶囊是真核生物水生类群的稀缺空间。这项工作为比较寄主地理范围内卵团内和卵团之间的微生物群落结构提供了基础。