Horizontal Gene Transfer http://textbookofbacteriology.net/HorizontalTransfer.gif HGT - Eukaryotes Sibbald et al 2020 Endosymbiotic gene transfer (EGT) You are what you eat https://ars.els-cdn.com/content/image/1-s2.0-S0168952598014942-gr3.jpg Doolittle, 1988 How to infer HGT But – contamination? Or Poor taxon sampling? Prokaryote to Prokaryote HGT Welch a kol. 2009 Eukaryote to Prokaryote HGT Guljamow A et al. Curr Biol. 2007;17(17):R757-9 •Extremely rare •Example: cyanobacterium Microcystis aeruginosa actin ad profilin HGT to Eukarytoes – controversial? Guljamow A et al. Curr Biol. 2007;17(17):R757-9 •Extremely rare •Example: cyanobacterium Microcystis aeruginosa actin ad profilin HGT to Eukarytoes – controversial? https://static-content.springer.com/image/art%3A10.1186%2F1471-2164-11-543/MediaObjects/12864_2010_ Article_3240_Fig3_HTML.jpg Jerlström-Hultqvist a kol. 2010, BMC Genomics Comparison of Giardia strains HGT to Eukarytoes – controversial? McCarthy and Fitzpatrick et al. 2019, Microbial genomics HGT to Eukarytoes – controversial? •HGT can be amazing source of new adaptations • •Help with lifestyle transitions – anaerobiosis, parasitism etc… •But not only, marine diatom Phaedactylum tricornutum contains > 5% HGT genes. • •Extremophilic red alga (Cyanidiophyceae) •Adaptation to extreme conditions also thanks to HGT (pH 0-4; temperature 56°C; high tolerance to toxic metals) •Bacterial genes for various ion channels, membrane pumps •Less introns and higher GC content in these genes •Donors: extremophilic prokaryotes Free-living Diplomonads • •Extremophilic red alga (Cyanidiophyceae) •Adaptation to extreme conditions also thanks to HGT (pH 0-4; temperature 56°C; high tolerance to toxic metals) •Bacterial genes for various ion channels, membrane pumps •Less introns and higher GC content in these genes •Donors: extremophilic prokaryotes Giardia muris Giardia intestinalis Spironucleus barkhanus Spironucleus salmonicida Spironucleus vortnes Ghost Hexamita Gyromonas sp. Trimitus sp. IT1 Trimitus sp. SM Hexamita Trepomonas sp. PPS6 BOT Trepomonas sp. PPS6 MACHU PICCHU Trepomonas sp. PC1 Trepomonas sp. PPS6 DAR Trepomonas sp. PPS6 ERAWAN Trepomonas sp. PPS6 VLADA7 Trepomonas agilis MIS2C Trepomonas agilis PIG Trepomonas agilis SOOS Trepomonas steinii CONGO Parasitic Ancestor Free-Living Ancestor Transition between lifestyles SM Hexamita BIG, NO NO!!! ±250 HGT genes Motifs following transmembrane domains in cysteine rich proteins are characteristic of VSPs 5 AA long – use arginine and lysine Trepomonas HGTs – adaptive to free-living Motifs following transmembrane domains in cysteine rich proteins are characteristic of VSPs 5 AA long – use arginine and lysine Etten 2020 How much Prokaryote to Eukaryote HGT But… •People tend to be conservative when inffering HGTs to Eukarytoes • •And unsystematic