The AGA grants EECG Research Awards to graduate and post-doctoral researchers who are at a critical point in their research, where additional funds would allow them to conclude their research project and prepare it for publication. 74 students and post-docs applied for funding this year.
The AGA Council is pleased to announce the recipients of this year’s EECG Awards:
1. $10,000 to Claire Couch (Oregon State University): The host as an ecosystem: relating the nasal microbiome to host genetics, behavior, physiology, and infection
2. $10,000 to Evan Kristiansen (Boston University): Linking genomic patterns of divergence and introgression across a butterfly hybrid zone
3. $8,000 to Marisa Lim (Stony Brook University): Molecular basis of hummingbird distributions in the high Andes
4. $9,740 to Jennifer Hellmann (University of Illinois Urbana-Champaign): Mechanisms driving multigenerational transmission of paternal stress in a new model system
5. $9,862 to Nicholas Kooyers (University of California, Berkeley): Investigating the role of pleiotropy in the adaptive divergence of plant defense arsenals
6. $10,000 to Steven Van Belleghem (Mississippi State University): Disentangling the genetic variation in regulatory modules underlying Heliconius butterfly color diversity
1. Couch – Microbiome
This project takes advantage of a unique opportunity to study the nasal microbiome in a natural population of African buffalo. Nasal swabs that have been collected from 65 animals throughout the course of a concurrent disease study are sequenced and analyzed to assess the genetic, behavioral, and physiological drivers of nasal microbiome variation using the detailed longitudinal dataset that is available. The overarching questions of my research project are (1) What drives variation in nasal microbiome composition? (2) What is the relationship between the nasal microbiome and respiratory infection? To carry out this project, I am analyzing metagenomic sequence data and then use generalized linear models, ordination methods, and correlation tests to find statistical relationships between the nasal microbiome, host traits, and disease. I currently have one year of sequence data, collected over four time points, that I have used in preliminary analyses.
2. Kristiansen – Butterfly hybrids
In this application, I propose to directly investigate the genomic patterns of divergence across the hybrid zone of L. lorquini and L. weidemeyerii, two butterfly species from the western United States. My primary goal is to understand the genomic basis of adaptation and speciation in the presence of gene flow. Specifically, I am testing whether strong natural selection for Batesian mimicry, a putative “speciation phenotype”, can drive lineage divergence despite the homogenizing effects of gene flow across a porous species boundary. Here I propose to test the hypothesis that divergent genomic regions between these butterfly species represent barriers to gene flow. Specifically, I will use Bayesian genomic cline analysis to detect outlier loci associated with reduced introgression and examine the correlation between patterns of genomic divergence and empirical estimates of gene flow across the phenotypic hybrid zone. Ultimately, these data will allow me to gain a better understanding of how selection and gene flow shape patterns of genomic variation between diverging lineages at an early stage along the evolving species boundary continuum.
3. Lim – Hummingbird distribution
My dissertation research is focused on dissecting the genetic basis of hummingbird adaptation to high altitude in the Andes Mountains. At first look, the harsh physical conditions of the Andes and demanding physiological constraints of hummingbirds seem at odds with the wide distribution and abundance of hummingbird species at high altitudes. However, several studies suggest that highland species are well-adapted for these challenges. In particular, new genomic methods are revealing specific amino acid changes, genes, and pathways involved in adaptation to survival in high altitude environments. I am using novel exon capture methods to investigate these genetic patterns across lowland and highland Andean hummingbird populations (n=233). With these data, I will test hypotheses for colonization of and adaptation to high altitude environments in hummingbirds specifically, but with applications to other highland species that evolved under similar environmental circumstances.
4. Hellmann – Paternal stress
Stressors experienced by one generation can influence the next. For example, parental stress, poor diet, and smoking have consequences for human health in subsequent generations, despite the fact that these generations are never exposed to the stressor. Adverse transgenerational consequences of stress to mothers have been well documented. However, a growing number of studies are suggesting that children can also inherit the experiences of their father via environmentally-induced epigenetic changes to sperm, specifically via microRNAs. MicroRNAs are small non-coding RNAs that regulate gene expression in the developing embryo. Although few studies have examined the mechanisms underlying transgenerational consequences of stress, these epigenetic changes may persist across multiple generations via effects on the germ line. To understand the mechanisms underlying the transmission of fathers’ experiences, I will inject threespined stickleback embryos from predator-unexposed parents with sperm microRNAs from predator-exposed fathers. By comparing the behavior and physiology of injected embryos with the behavior and physiology of offspring sired by predator-exposed fathers, I will determine if the effects of paternal experience on offspring are mediated by sperm microRNAs. Further, I will determine if these effects persist multiple generations by exploring if differences among treatment groups affect grandoffspring.
5. Kooyers – Plant defense
Determining how adaptive combinations of traits arose requires knowledge of the genetic basis of phenotypic evolution, specifically whether correlated phenotypes arise via pleiotropic mutations or through independent genetic mechanisms. Here, I propose to use phytochemical defense arsenals in the widespread species, Mimulus guttatus, to evaluate the role of pleiotropy in multivariate phenotypic adaptation. Phenylpropenoid glycosides (PPGs) are the dominant chemical defense in M. guttatus with most populations constitutively producing seven distinct PPGs. Preliminary data indicates strong divergence among populations in both PPG arsenal composition and abundance that is associated with herbivore pressure and life history. I leverage populations with dramatically different total PPG concentrations, arsenals compositions, and life histories within a quantitative trait locus (QTL) mapping approach to investigate how pleiotropy has contributed to adaptive divergence. We predict that pleiotropy has played a substantial role in defense arsenal divergence both in controlling the allocation of resources to individual PPGs and more generally in allocation total defense vs. growth.
6. Van Belleghem – Butterfly color
In Heliconius, I have been able to identify an intricate set of genomic intervals that regulate the expression of major color pattern genes. The identification of these intervals has been possible due to extensive geographic sampling and despite low numbers of genome samples for each population. By performing targeted enrichment sequencing of a large number of samples, I propose to (i) leverage the power of strongly admixed Heliconius erato hybrid zones to further map the genetic variation related to different color patterns and (ii) identify additional color pattern loci that have small effects on color pattern variation. These results will provide a more comprehensive and realistic understanding of the complex genomic architecture that underlies color pattern diversity.
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