Vanderbilt undergraduate compares nuclear and mitochondrial genomic evolution of the fungi Aspergillus section Flavi
By Kelly Tingle, Evolutionary Studies communications assistant
Former Vanderbilt University undergraduate student Miya Hugaboom provides insight into fungal mitochondrial genomic evolution in a paper she published recently as lead author, along with Biological Sciences graduate student Annie Hatmaker and Professor Antonis Rokas.
The study focused on the mitochondrial genomes of 20 different Aspergillus species, a type of fungi, to examine the relationships within section Flavi, a group of closely related species within the genus Aspergillus. The team found that while the genomic content of Flavi nuclei is approximately 1000 times larger than that of the mitochondria, phylogenies (the relationships between organisms and their common ancestor) produced by mitochondrial genomes are consistent with those produces by nuclear genomes. This is significant because it shows that mitochondrial genomes may be underutilized in constructing phylogenies, as most previous studies have focused only on nuclear genomes.
Hatmaker explained that mitochondria have separate genomes from the nucleus of the same cell. They are also inherited in cell reproduction in a different way than nuclei; therefore, they have a distinct evolutionary history.
“[Mitochondrial genomes] offer a unique phylogenetic perspective when compared to their nuclear counterparts,” described Hugaboom.
“Fungal mitochondria have been linked to diverse processes including energy metabolism, cell differentiation, drug resistance, biofilm and hyphal growth regulation, and virulence, among others, so an understanding of these organellar genomes is important to grasping the complete genomic profile of section Flavi,” explained Hugaboom. “There is a dearth of genomic analyses of section Flavi that are mitochondrial in focus, with most focusing exclusively on nuclear genomes.”
Hatmaker explained that she helped Hugaboom with assembling and annotating mitochondrial genomes and constructing phylogenetic trees.
Aspergillus flavus, a species of fungus within Aspergillus section Flavi, can produce toxins that are harmful to mammals. VU alumni Miya Hugaboom studied the nuclear and mitochondrial genomes of 20 different Aspergillus species within section Flavi. Photo credit: G. W. Willis; Getty Images.
“I also constructed a phylogeny using nuclear genes, whereas Miya constructed a phylogeny from the mitochondrial genes. She was then able to compare the two phylogenies,” added Hatmaker.
“[Results from this study suggest that] the two datasets, nuclear and mitochondrial, had overall similar evolutionary histories,” said Hatmaker. “We now have a comparison point for other fungal species, allowing us to contrast this group of species with others.”
Hugaboom joined the Rokas Lab after completing an independent study course taught by Hatmaker and started this research as an undergraduate honors thesis project. Hatmaker served as Hugaboom’s mentor for the project.
“Miya is wonderful to work with—she was transparent about her progress and any challenges, and she was extremely hardworking, motivated, and interested in the project,” described Hatmaker.
Hugaboom graduated from Vanderbilt in 2022 and is now a postgraduate associate at the Yale School of Medicine.
Funding Statement: This study was funded by Vanderbilt Data Science Institute Summer Research Program, the National Institutes of Health/National Eye Institute (F31 EY033235), the National Science Foundation (DEB-2110404), the National Institutes of Health/National Institute of Allergy and Infectious Diseases (R56 AI146096 and R01 AI153356), and the Burroughs Wellcome Fund.
Citation: Hugaboom, M., Hatmaker, E.A., LaBella, A.L., Rokas, A., (2022). Evolution and codon usage bias of mitochondrial and nuclear genomes in Aspergillus section Flavi, G3 Genes|Genomes|Genetics, jkac285, https://doi.org/10.1093/g3journal/jkac285