Papers we discussed.
Trung:
Metzger, C. M. J. A., Luijckx, P., Bento, G., Mariadassou, M. & Ebert, D. The Red Queen lives: Epistasis between linked resistance loci. Evolution 70, 480–487 (2016).
Among the major hypotheses explaining the origin and maintance of sexual reproduction and recombination is the Red Queen hypothesis. Although the Red Queen dynamic is used in many theoretical models, there is still a lack of empirical evidence supporting the assumptions of the Red Queen hypothesis. Builiding upon Luijckx’s 2013 study that found evidence for genotype matching between host and parasites, Metzger was able to determine the genetic architecture of that system to be a biallelic three loci system, and provide evidence that there is an epistasis effect between the the three linked loci, a mechanism that supports the the Red Queen dynamic.
Marelize:
Murray, S., Pascoe, B., Meric, G., Mageiros, L., Yahara, K., Hitchings, M., . . . Sheppard, S. (2017). Recombination-mediated host adaptation by avian staphylococcus aureus. Genome Biology and Evolution, 9(4), 830-842. 10.1093/gbe/evx037
The authors were interested in characterizing the the evolutionary events in CC5 isolates that accompanied the colonization of chickens from humans. Through comparison of the different isolates with phenotypically divergent S. aureus they provided evidence for the genetic basis of poultry adaptation. By relating adaptive hotspots to gene function, and using laboratory phenotyping assays, they also described an evolutionary history of rapid avian host adaptation of a globally disseminated animal pathogen.
Swatantra:
Hoenen, T., Safronetz, D., Groseth, A., Wollenberg, K. R., Koita, O. A., Diarra, B., … & Sarro, Y. S. (2015). Mutation rate and genotype variation of Ebola virus from Mali case sequences. Science, 348(6230), 117-119.
This is about the controversy that was in spotlight recently when one of the finding made by Hoenen, the rate of evolution in Ebola virus is half than previously reported by Gire. et. al (2014) when compared to Ebola’s long-term rate of change in its animal host. But later, other researchers questioned the way Hoenen’s lab calculated the rate of evolution and pointed it out to being not an appropriate measure to assess the rate of evolution, using two small clusters of outbreaks that happened in Mali. Later, Hoenen Lab had to recalculate the rate of evolution and produced a figure half of that of Gire et. al. (1.3 X 10-3 substitution per site per year).