Systematic and functional analysis of horizontal gene transfer events in diatoms.

摘要: Diatoms are a diverse group of mainly photosynthetic algae, responsible for 20% worldwide oxygen production, which can rapidly respond to favourable conditions and often outcompete other phytoplankton. We investigated the contribution horizontal gene transfer (HGT) its ecological success. A systematic phylogeny-based bacterial HGT detection procedure across nine sequenced diatoms showed that 3-5% their proteome has origin large influx occurred at ancestor diatoms. More than 90% genes expressed, species-specific in Phaeodactylum tricornutum undergo strong purifying selection. They implicated several processes including environmental sensing, expand metabolic toolbox. Cobalamin (vitamin B12) is an essential cofactor roughly half only produced by bacteria. Genes involved final synthesis were detected as HGT, five consecutive enzymes Fragilariopsis cylindrus. This might give originating from Southern Ocean, region typically depleted cobalamin, competitive advantage. Overall, we show prevalent mechanism actively used adaptive capabilities.