Phylogeny vs genome reshuffling: horizontal gene transfer

Abstract

The evolutionary events in organisms can be tracked to the transfer of genetic material. The inheritance of genetic material among closely related organisms is a slow evolutionary process. On the other hand, the movement of genes among distantly related species can account for rapid evolution. The later process has been quite evident in the appearance of antibiotic resistance genes among human and animal pathogens. Phylogenetic trees based on such genes and those involved in metabolic activities refl ect the incongruencies in comparison to the 16S rDNA gene, generally used for taxonomic relationships. Such discrepancies in gene inheritance have been termed as horizontal gene transfer (HGT) events. In the post-genomic era, the explosion of known sequences through large-scale sequencing projects has unraveled the weakness of traditional 16S rDNA gene tree based evolutionary model. Various methods to scrutinize HGT events include atypical composition, abnormal sequence similarity, anomalous phylogenetic distribution, unusual phyletic patterns, etc. Since HGT generates greater genetic diversity, it is likely to increase resource use and ecosystem resilience.

Potential Emergence of Multi-quorum Sensing Inhibitor Resistant (MQSIR) Bacteria

“…Occurrence of horizontal gene transfer (HGT) and despotic mutations favour the prospects of bacterial evolution [174,175]. It is also the reason for multiplicity and the complexity of QS based communication network.…”

Challenges and Opportunities for Customizing Polyhydroxyalkanoates

“…The major challenges to make PHAs economically viable, is to make them easier to process and handle. Manipulating the genetic makeup of bacteria appears to be the most obvious choice for achieving these targets [4,5,14]. Interestingly, this can be also achieved by adopting strategies such as selection of bacteria, suitable substrates, appropriate feeding regime, and variations in physiological conditions [15].…”

Cross-Species Induction and Enhancement of Antimicrobial Properties in Response to Gamma Irradiation in Exiguobacterium sp. HKG 126

“…Natural genetic transformation is also believed to be the essential mechanism for exploiting innate microbial capacity in bacterial populations, during mixed culture fermentation via horizontal gene transfer. In an early report, microbial sequencing studies and result of genome analyses indicates that the biosynthetic potential of microbial strains is much greater than that observed by traditional natural product isolation [22][23][24]. Therefore, with countless possible microbial combinations and increasingly sophisticated chemical isolation and structure determination methods, the potential for mixed fermentation in natural product drug discovery seems quite promising.…”