Year: 2022

BOLT-ON GENE SETS. “Horizontal gene transfer can fundamentally alter the character of a microbial species by introducing fully functional genes and gene clusters that can confer complex phenotypes and functions that allow effective and competitive exploitation of new niches.” https://lnkd.in/djKBnru View in LinkedIn

SLOW ROAD. “In contrast, variation introduced by point mutation will, most of the time, only adjust preexisting phenotypes.” https://lnkd.in/djKBnru View in LinkedIn

DYNAMIC NICHES. “Because gene acquisitions can increase the metabolic repertoire of the cell, we need not view the microbial niche as a static domain, within which fitter variants constantly arise and sweep through the population. Although an organism may evolve to improve its fitness within its current niche, it is more likely that gene acquisition will allow exploitation of a related environment.” https://lnkd.in/djKBnru View in LinkedIn

REDEFINING EVENT. “The microbial niche can be considered a dynamic domain, which is redefined after each gene transfer event. This alternation of niche boundaries then imposes a different filter on the influx of foreign DNA, imparting different selective values on incoming genes.” https://lnkd.in/djKBnru View in LinkedIn

RAPID AND DYNAMIC. “Because the dynamic microbial niche is redefined after every horizontal gene transfer, lineage separation would occur if the populations exploring two newly derived niches were both successful. Surveys among closely related bacterial species support the hypothesis that the differences between them arose primarily by gene loss and gene acquisition, not by mutational processes.” https://lnkd.in/djKBnru View in LinkedIn

BROAD VARIABILITY. “The niches created by gene transfer events vary widely in their stability or novelty. Some events, like the acquisition of an antibiotic resistance gene, allow for transient exploration of a new environment, but this lineage may not persist over evolutionary time (that is, this event will likely not found a clade of antibiotic-resistant bacteria distinguished by their shared ability to be resistant to a particular antibiotic).” https://lnkd.in/djKBnru View in LinkedIn

NICHE SALTATIONS. “Rarely, a gene transfer event may allow for the formation of radically different organisms that inhabit niches completely unreachable by organisms relying on mutational processes alone to explore environments.” https://lnkd.in/djKBnru View in LinkedIn

RADICAL ORGANISMS IN UNREACHABLE NICHES. “Examples of such lineages include the green plants (acquiring chloroplast by endosymbiosis, methanotrophs (gaining the ability to synthesize critical cofactors by acquiring genes from methanogenic archaea, cyanobacteria (gaining a second photosystem allowing oxygenic photosynthesis, and bacteria exploiting halorhodopsin homologues as light-driven proton pumps.” https://lnkd.in/djKBnru View in LinkedIn

HORIZONTAL ORTHOLOGS. “Most bacterial genome sequences reveal an abundance of paralogs which are often viewed as products of within-lineage duplication and divergence. However, many must be the result of the reuniting through horizontal gene transfer of orthologs that have diverged in separate lineages. Recognizing this encourages a rethinking of standard models of gene duplication and divergence.” https://lnkd.in/djKBnru View in LinkedIn

PRE-ISOLATION SPECIATION. “These models resemble sympatric speciation for genes, where ecological distinctiveness must arise before reproductive isolation.” https://lnkd.in/djKBnru View in LinkedIn