Red Sea SAR11 and Prochlorococcus Single-Cell Genomes Reflect Globally Distributed Pangenomes.

摘要: ABSTRACT Evidence suggests many marine bacteria are cosmopolitan, with widespread but sparse strains poised to seed abundant populations under conducive growth conditions. However, studies supporting this “microbial bank” hypothesis have analyzed taxonomic marker genes rather than whole genomes/metagenomes, leaving open the possibility that disparate ocean regions harbor endemic gene content. The Red Sea is isolated geographically from rest of and has a combination high irradiance, temperature, salinity unique among oceans; we therefore asked whether it harbors We sequenced assembled single-cell genomes 21 SAR11 (subclades Ia, Ib, Id, II) 5 Prochlorococcus (ecotype HLII) samples combined them globally sourced reference cluster into ortholog groups (OGs). Ordination OG composition could distinguish clades, including phylogenetically cryptic ecotypes LLII LLIII. Compared genomes, 1% 17% OGs were (RS-OGs). Most (83%) RS-OGs had no annotated function, 65% expressed in diel metatranscriptomes, suggesting they functional. Searching Tara Oceans metagenomes, as likely be found non-RS-OGs; nevertheless, other warm distinguished cooler using relative abundances OGs. results suggest prevalence these surface largely differences population metagenomes manifested by abundance complete presence/absence IMPORTANCE Studies shown sequence seawater selected environment deeper deeper, approach finding every bacterial taxon known for whole. such focused on raising lack endemism method investigation. took water body, Sea, single cells it. compared those available around ocean-spanning metagenomes. showed not nevertheless common across global These Baas Becking’s “everything everywhere, selects” also applies groups. This widely dispersed functional diversity may give oceanic microbial communities capacity respond rapidly changing