On October 25th, 2018, Dr. Jason C. Slot, a fungal evolutionary genomics researcher, attended our Biology 3401 class to discuss his research and observations on the impact of analyzing the genomic information of distinct species to gain evolutionary information. Specifically, Dr. Slot delved into the two cases of the Podospora anserina and the Psilocybin mushrooms, which are both a type of fungus that display a level of horizontal gene transfer that illuminate phylogenetic information about their type of organism. While it will be elaborated upon, the awareness of the metabolic pathway gene transfer in Podospora anserina and the occurrence of unique gene clusters in Psilocybin mushrooms that do not correlate with close relatives can imply meaningful results in the presence of horizontal gene transfer (HGT).
First, it is important to note that the evolutionary history of Podospora anserina could not be understood to its greatest extent had it not been for the understanding of HGT, which is the “Duplication of genetic material from a genetic locus in one species to one in another species” (Slot 2018). After the analysis of the genes in the fungi, it was extraordinary to see that 14.5%of the horizontally transferred genes were determined to be genes responsible for secondary metabolite synthesis, transport, and catabolism (Slot 2018). Furthermore, a study done on Podospora anserina further concluded the fact that the necessity to metabolize from different complex carbon sources required horizontal gene transfer to form a dynamic evolutionary history of the fungi (Espagne et al. 2008). Moving onward to HGT, as it pertains to the specific mechanisms, it was vital that students understood the “selfish cluster hypothesis”, which communicated the idea that weakly selected genes can survive through the clustering of their gene with others to transfer to distinct species (Slot 2018). It is believed that the clustering is the reason that Psilocybin, which is a cluster of different chemicals, has been identified as a prevailing feature in mushrooms, due to its absence in close relatives signaling HGT in recent history to dung (why dung is preferred is still in question). Also, research done on HGT now extrapolates such results to challenge previous notions that eukaryotes could not observe HGT, as there has been increasing results suggesting the prevalence of this genetic transfer throughout the entire tree of life (Qiu et al. 2016). This allows us to be aware of the changing dynamics in evolutionary research, and the further finding will always enhance our understanding of the most core theorems and truths of biology.
While the information may have seemed daunting throughout the presentation, having to complete some independent research and analyze professional publications was an opportunity to digest material that was slightly beyond my understanding. Such work better prepares me for future endeavors in the scientific field, which requires that the populace of, in my case, dental professionals have the ability to collaborate with other people and to understand new studies done in the field, no matter the specific content’s relevance to your own work.
- Slot, Jason. 2018, October, 25. Reading the genomes of microorganisms to form ecological
and evolutionary hypotheses. Seminar presented at: Biology 3401, Ohio State University. Columbus, Ohio.
- Espagne E et al. The genome sequence of the model ascomycete fungus Podospora anserina.
2008 May 6 [accessed 2018 Nov 1]. https://genomebiology.biomedcentral.com/articles/10.1186/gb-2008-9-5-r77
- Qiu H et al. Extensive horizontal gene transfers between plant pathogenic fungi. 2016 May
23 [accessed 2018 Nov 1]. https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-016-0264-3