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海绵动物是最原始的后生动物,营底栖、滤食性生活,它们体内共生有丰富的微生物菌落,包括仅在海绵动物体内存在的特异性微生物。为了探讨海绵特异微生物是否与宿主存在协同演化关系,我们基于16SrRNA基因序列利用宽松分子钟方法估测了各个门类中海绵特异微生物的分歧时间,并与海绵动物的化石记录及分子谱系年代学结果相比较。结果表明:多数微生物门类中海绵特异微生物的分支分化发生在新元古代(800—1000Ma),与海绵动物的分子化石记录和当前分子钟估算结果之间存在一定程度的一致性,说明微生物与宿主海绵动物之间存在一定的协同演化关系。少数门类中海绵特异微生物分化时间过早于(如蓝细菌,2200Ma)或者过晚于(如古细菌,148Ma;Alphaproteobacteria,480Ma)新元古代,这可能是由于系统采样等因素所致,有待于进一步的分析与研究。
Sponge is the most primitive metazoan, camp benthic, filter-feeding sex life, they symbiosis with a large number of microbial colonies, including only sponges in the presence of specific microorganisms. In order to investigate whether the sponge-specific microbes co-evolved with the host, we used the divergent molecular clock method to estimate the divergence time of sponge-specific microorganisms in each taxon based on the 16S rRNA gene sequence. The results were compared with the fossil record of sponge and the molecular pedigree Compare The results showed that the divergence and divergence of sponge-specific microorganisms in most of the microbial families occurred in the Neoproterozoic (800-1000 Ma) with some agreement with the molecular fossil record of sponge and the estimation of the current molecular clock, indicating that the microbe and host There is a certain co-evolution relationship between sponges. In a few categories, the spontaneous differentiation of sponges is premature (eg cyanobacteria, 2200Ma) or too late (eg, Archaea, 148Ma; Alphaproteobacteria, 480Ma), probably due to systematic sampling and other factors Further analysis and research.