title: Association between translation efficiency and horizontal gene transfer within microbial communities.
abstract: Horizontal gene transfer (HGT) is a major force in microbial evolution. Previous studies have suggested that a variety of factors, including restricted recombination and toxicity of foreign gene products, may act as barriers to the successful integration of horizontally transferred genes. This study identifies an additional central barrier to HGT-the lack of co-adaptation between the codon usage of the transferred gene and the tRNA pool of the recipient organism. Analyzing the genomic sequences of more than 190 microorganisms and the HGT events that have occurred between them, we show that the number of genes that were horizontally transferred between organisms is positively correlated with the similarity between their tRNA pools. Those genes that are better adapted to the tRNA pools of the target genomes tend to undergo more frequent HGT. At the community (or environment) level, organisms that share a common ecological niche tend to have similar tRNA pools. These results remain significant after controlling for diverse ecological and evolutionary parameters. Our analysis demonstrates that there are bi-directional associations between the similarity in the tRNA pools of organisms and the number of HGT events occurring between them. Similar tRNA pools between a donor and a host tend to increase the probability that a horizontally acquired gene will become fixed in its new genome. Our results also suggest that frequent HGT may be a homogenizing force that increases the similarity in the tRNA pools of organisms within the same community.
authors.affiliation: Faculty of Mathematics and Computer Science, Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Blavatnik School of Computer Science, School of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel.
authors.forename: Tamir
authors.initials: T
authors.lastname: Tuller
authors.forename: Yana
authors.initials: Y
authors.lastname: Girshovich
authors.forename: Yael
authors.initials: Y
authors.lastname: Sella
authors.forename: Avi
authors.initials: A
authors.lastname: Kreimer
authors.forename: Shiri
authors.initials: S
authors.lastname: Freilich
authors.forename: Martin
authors.initials: M
authors.lastname: Kupiec
authors.forename: Uri
authors.initials: U
authors.lastname: Gophna
authors.forename: Eytan
authors.initials: E
authors.lastname: Ruppin
mesh_terms: D003062:Codon; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D014176:Protein Biosynthesis; D012343:RNA, Transfer / Q000235:genetics
chemical_list: D003062:Codon; D012343:RNA, Transfer