Horizontal Gene Transfer of the Lux Operon Observed in the Genus Vibrio.
Mentor 1
Charles Wimpee
Location
Union Wisconsin Room
Start Date
5-4-2019 1:30 PM
End Date
5-4-2019 3:30 PM
Description
Horizontal gene transfer has had an enormous effect on the evolution of bacterial genomes. Typically, this event would be detected retrospectively, in congruent phylogenetic trees or anomalous base composition. In certain cases horizontal gene transfer can result in the replacement of a resident gene. When this occurs, it is possible that the recipient bacteria will (at least temporarily) harbor two nonidentical copies of the same gene. Our lab has seen multiple examples of this with the luxA gene, strongly indicating ongoing horizontal gene transfer. Merodiploids have been detected by sequence analysis showing multiple occurrences of double peaks in the same place. The gene was amplified using high fidelity Phusion polymerase to preclude the mistakes made by the more error prone Taq polymerase. The products of the amplification were cloned and sequenced. Results of the sequence showed that where double peaks were previously seen now had either one of the two base pairs seen in the clones. This indicates the presence of two different copies of the luxA gene. One copy is 99% identical to luxA from Vibrio harveyi, and the other copy is 99% identical to luxA from Vibrio campbellii. The two copies are 97% identical to one another. The entire Lux operon was also amplified, cloned and sequenced. The results of this sequence indicated the presence of two different copies of the Lux operon.
Horizontal Gene Transfer of the Lux Operon Observed in the Genus Vibrio.
Union Wisconsin Room
Horizontal gene transfer has had an enormous effect on the evolution of bacterial genomes. Typically, this event would be detected retrospectively, in congruent phylogenetic trees or anomalous base composition. In certain cases horizontal gene transfer can result in the replacement of a resident gene. When this occurs, it is possible that the recipient bacteria will (at least temporarily) harbor two nonidentical copies of the same gene. Our lab has seen multiple examples of this with the luxA gene, strongly indicating ongoing horizontal gene transfer. Merodiploids have been detected by sequence analysis showing multiple occurrences of double peaks in the same place. The gene was amplified using high fidelity Phusion polymerase to preclude the mistakes made by the more error prone Taq polymerase. The products of the amplification were cloned and sequenced. Results of the sequence showed that where double peaks were previously seen now had either one of the two base pairs seen in the clones. This indicates the presence of two different copies of the luxA gene. One copy is 99% identical to luxA from Vibrio harveyi, and the other copy is 99% identical to luxA from Vibrio campbellii. The two copies are 97% identical to one another. The entire Lux operon was also amplified, cloned and sequenced. The results of this sequence indicated the presence of two different copies of the Lux operon.
