Seminar: Interdepartmental genetics
| Date/Time: | Tuesday, 25 Jul 2017 from 3:10 pm to 4:00 pm |
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| Location: | 1102 Molecular Biology Building |
| Cost: | Free |
| Contact: | Linda Wild, |
| Phone: | 515-294-7697 |
| Channel: | Graduate College |
| Categories: | Lectures |
| Actions: | Download iCal/vCal | Email Reminder |
After domestication from lowland teosinte in the Mexican subtropics maize colonized the highlands of Mexico and South America. In both the Mexican and South American highlands, maize encountered lower temperatures and, in volcanic areas, soils with low phosphorus availability. We hypothesize that these two abiotic stresses were major selective forces during maize adaptation to the highlands and shaped glycerolipid metabolism since low temperature and P deficiency have opposite effects on the relative content of glycerolipid species. We are using this system to explore how metabolic pathways change during the process of local adaptation, combining metabolic phenotyping with quantitative and population genetics to identify particular loci under selection during adaptation.
I will present data on common garden experiments in highland and lowland Mexican field sites where we grew a maize RIL mapping population and a 120-landrace diversity panel composed of both highland and lowland maize. Using these plants we have identified loci potentially involved in glycerolipid metabolism. I will present these results and focus, in particular, on an interesting QTL on chromosome 3 where a candidate phospholipase gene seems to be responsible for phosphatidylcholine (PC) to lysophosphatidylcholine (lyso-PC) conversion.
Our phenotypic data together with population differentiation data suggest genes controlling PC to lyso-PC conversion were under selection during the process of maize adaptation to the highlands. We are now determining the importance of balancing PC to lyso-PC species for highland adaptation, the extent to which there was convergence of this phenotype in Mexican and South American highland maize, and how this knowledge relates to a broader understanding of maize adaptation to different temperatures and phosphorus levels.