A number of examples of putative eukaryote-to-prokaryote horizontal gene transfer (HGT) have been proposed in the past using phylogenetic analysis in support of these claims but none have attempted to map these gene transfers to the presence of genomic islands (GIs) in the host. Two of these cases have been examined in detail, including an ATP sulfurylase (ATPS) gene and a class I fructose bisphosphate aldolase (FBA I) gene that were putatively transferred to cyanobacteria of the genus Prochlorococcus from either green or red algae, respectively. Unlike previous investigations of HGT, parametric methods were initially used to detect genomic islands, then more traditional phylogenomic and phylogenetic methods were used to confirm or deny the HGT status of these genes. The combination of these three methods of analysis- detection of GIs, the determination of genomic neighborhoods, as well as traditional phylogeny, lends strong support to the claim that trans-domain HGT has occurred in only one of these cases and further suggests a new insight into the method of transmission of FBA I, namely that cyanophage-mediated transfer may have been responsible for the HGT event in question. The described methods were then applied to a range of prochlorococcal genomes in order to characterize a candidate for eukaryote-to-prokaryote HGT that had not been previously studied by others. Application of the same methodology used to confirm or deny HGT for ATPS and FBA I identified a ⊗12 fatty acid desaturase (FAD) gene that was likely transferred to Prochlorococcus from either green or red algae.

为了支持这些主张，过去已经提出了许多利用系统进化分析推定的真核生物至原核生物水平基因转移的例子，但是没有一个人试图将这些基因转移映射到基因组岛（GIs）的存在。主人。已对其中的两个案例进行了详细检查，其中包括一个ATP硫化酶（ATPS）基因和一个I类果糖双磷酸醛缩酶（FBA I）基因，这些基因被假定转移至原绿球藻属的蓝细菌中。分别来自绿藻或红藻。与以前的HGT研究不同，参数方法最初用于检测基因组岛，然后使用更传统的系统发育和系统发育方法来确认或否认这些基因的HGT状态。这三种分析方法的结合-地理标志的检测，基因组邻域的确定以及传统的系统发育学，为跨域HGT仅在其中一种情况下发生的说法提供了有力的支持，并进一步提出了新的见解。进入FBA I的传播方式，即可能是由噬菌体介导的传递导致了所讨论的HGT事件。然后将所描述的方法应用于一系列的原球菌基因组，以表征以前没有被其他人研究过的真核生物至原核生物HGT的候选物。应用用于确认或拒绝ATPS和FBA的HGT的相同方法，我确定了可能转移至的to12脂肪酸去饱和酶（FAD）基因。绿藻或红藻的原球菌。