Understanding the Genomic Basis of Adaptation to Extreme Environments
Event details
| Date | 01.11.2013 |
| Hour | 14:15 |
| Speaker |
Prof. Joanna L. Kelley, Washington State University, Pullman, WA (USA) Bio: Dr. Kelley is currently an Assistant Professor in the School of Biological Sciences and a member of the Center for Reproductive Biology at Washington State University. She received her PhD in Genome Sciences from University of Washington with advisor Willie Swanson and held postdoctoral positions at University of Chicago in Human Genetics with Molly Przeworski and at Stanford University in the Department of Genetics with Carlos Bustamante. Joanna’s research focuses on the genomic basis of adaptation, with a special emphasis on extreme environments. |
| Location | |
| Category | Conferences - Seminars |
Organisms inhabit most of the globe and have adapted to all types of extreme environments. By analyzing genomes of organisms adapted to extreme environments we aim to understand the genomic basis of adaptation. Here we take two approaches by studying the genome of a fly living in Antarctica and transcriptomes of fish living in sulfidic streams. B. antarctica has the smallest insect genome sequenced thus far, a feature that offers insights on genome evolution. With a similar number of genes compared to other Diptera, this unusually small genome shows a very low repeat density. The few transposable elements present in the genome are mainly ancient inactive retroelements. A reduction of intron length further contributes to the small genome size. I will also discuss fish living in sulfidic streams. Multiple populations of Poecilia fish have adapted to hydrogen sulfide-rich springs from ancestral freshwater streams, making them an ideal system to study the reproducibility of the evolutionary process. Hydrogen sulfide (H2S) interrupts the mitochondrial respiratory chain and is also associated with severe hypoxia, and therefore highly toxic. The high level of dissolved H2S suggests that gills are one of the relevant tissues where changes associated to the adaptation to H2S might occur. Transcriptome RNA-sequencing data from gills provides unique evidence for the genomic and transcriptional basis of adaptation to this extreme environment. We extracted RNA from 36 individuals of Poecilia mexicana and P. sulphuraria, 12 from each of three drainages with replicated sulfidic (n=6) and non-sulfidic (n=6) locations. De novo transcriptome assembly is accomplished by combining data across individuals.Comparing transcriptional changes across replicated pairs of sulfidic and non-sulfidic populations, we identify convergent evidence of differential expression. Our analysis shows that over 5% of genes exhibit significant differential expression in all drainages, when all pairs of sulfidic and freshwater streams are assessed.
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Practical information
- Informed public
- Free
Organizer
- Prof. Jeffrey Jensen