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.
The AGA Council is pleased to announce the recipients of this year's EECG Awards:
1. $9,806 to Murielle Aalund (Michigan State University): Effects of diet on female sperm selectivity in rapidly evolving sticklebacks
2. $9,598 to Matthew J. Rubin (Donald Danforth Plant Science Center): Using comparative transcriptomics to characterize adaptive cold responses
3. $9,880 to Will Ryan (University of Alabama at Birmingham): Measuring the relationship between fission history and somatic mutation accumulation in a clonal sea anemone
4. $9,975 to Georgy Semenov (University of Colorado, Boulder): Genetic architecture and asymmetric introgression of plumage-related reproductive barriers in hybridizing birds
5. $10,000 to Chloé Berger (Université Laval, Institute of Integrative Biology and Systems): New insights into the molecular cross-talk between the manipulative cestode Schistocephalus solidus and its fish host the threespine stickleback using high throughput genomics and proteomics
6. $8,360 to Rebekah Oomen (Dalhousie University): The genomic basis and spatial scale of variation in thermal responses of Atlantic cod
7. $4,000 to Brendan J. Pinto (Marquette University): Small geckos yield great insight into the genomic underpinnings of speciation
8. $9,980 to Anna Ward (University of Iowa): Investigating evolution of complex traits and the role of host-shifting among the North American oak gall wasps
1. Aalund – Threespine stickleback sperm selectivity
Animals spend most of their life searching for ideal mates, in order to produce the best possible offspring. Even after mating, sperm can be selected to avoid fertilization by an incompatible male, either inside the female or via the ovarian fluid surrounding their eggs, but females are likely to vary in their sperm selection ability. We will study sperm selection in Icelandic threespine sticklebacks, an externally fertilizing fish species whose eggs are exposed to both harsh environmental conditions and sneak-fertilization by non-chosen males. Studying fish from different types of lakes and marine populations, we will ask how the external environment affects a female’s ability to select the best sperm for their eggs. We will use a combination of fieldwork, controlled in-vitro fertilization and cutting-edge sequencing and proteomics methods to search for candidate proteins involved in sperm selection. Sticklebacks are a model of sexual selection and speciation studies, that are facing risks of both inbreeding and hybridization in changing and disturbed habitats. Understanding the conditions that favor female sperm selection, avoiding fertilization by incompatible mates and negative fitness consequences for the whole population, will help us predict their adaptation to natural and human-induced habitat changes and inform commercial breeding practices.
2. Rubin – Adaptive cold responses
Correctly timing major life-history transitions to occur at optimal times of the year is critical to an organism’s fitness. Although natural environments are highly variable, there are some aspects of the environment that are predictable, including large shifts in temperature across seasons. Plants use these pronounced cold cues to correctly time two major life-history transitions—germination and flowering. Research has focused on the phenotypic responses for both of these traits. However, genetic analysis (QTL mapping and comparative transcriptomics) have only been completed for flowering responses. Using recently identified mutants, we will characterize the gene networks involved in germination responses providing a critical link to how plants respond to cold at a different life stage. Understanding the magnitude of overlap between the genetic pathways used to perceive cold for germination and flowering timing will provide insights into how selection has acted jointly on phenological timing across the entire life cycle.
3. Ryan – Clonal sea anemone
Genomic sequencing data will be generated using DNA extracted from preserved samples from a completed experiment and used to estimate the relationship between fission rate and the accumulation of somatic mutations in a sea anemone which shows high intraspecific variation in intrinsic fission behavior.
4. Semenov – Hybridizing birds
My study aims to uncover both the genetic architecture and the mechanism underlying asymmetric introgression of plumage coloration in Motacilla alba alba and M. a. personata subspecies of a passerine bird, the white wagtail. Coloration of the head and neck regions are important mating signals associated with reproductive barriers in the alba and personata hybrid zone; personata-like plumage traits have advanced significantly via introgression into alba genomic background and territory by ~300 km (Semenov et al. 2017; Fig 1). I have recently sequenced whole genomes of parental alba (n=10) and personata (n=10) phenotypes originating from the center of the hybrid zone where admixture is ongoing, which revealed that the two plumage types can be distinguished by two narrow (<400kb total) highly divergent genomic regions (Fig 2). These regions are located on chromosomes 1A and 20, and together contain ~10 genes involved in melanogenesis, cell signaling, and developmental processes. One of these regions harbors Agouti Signaling Protein (ASIP) and shows variation patterns consistent with dominant inheritance of the alba-allele. These results provide a putative link between plumage-mediated positive assortative mating, the underlying genetic differences, and the mechanism promoting their asymmetric introgression; however, confidently establishing this link requires additional whole-genome resequencing of individuals with intermediate plumage and individuals sampled from regions of allopatry.
5. Berger – Cestodes and threespine sticklebacks
Animals exhibit a fascinating diversity of adaptive behaviours. However, these behaviours can be disrupted following parasitic infection. One striking example is the threespine stickleback that loses its anti-predatory behaviour following infection by the cestode Schistocephalus solidus. Previous studies suggested that this behavioural change in the fish host could be the result of a direct manipulation by the parasite in order to increase its transmission probability to its final host, a bird. However, it is necessary to study the molecular interactions between the worm and the fish in order to better understand how such alterations can evolve in nature. During my PhD, I am interested in the potential molecular cross-talk between S. solidus and its stickleback host through the secretions of S. solidus (the secretome), which could include candidate molecules that would be responsible for the behavioural changes. To determine if the worm could manipulate its host by secreting manipulative molecules, we aim to describe the genome, the proteome (i.e. all the proteins expressed in worm tissues) and the secretome of S. solidus using high throughput methods, combined with functional analysis.
6. Oomen – Atlantic cod
We investigate the genomic basis and spatial scale of variation in thermal responses of Atlantic cod (Gadus morhua), with the over-arching aim of improving our understanding of plastic and evolutionary responses to environmental change in natural populations. We combine thermal gradient common-garden experiments conducted on cod larvae from four locations with large-scale RNA sequencing and SNP genotyping to characterize variation in gene expression, growth reaction norms, and survival. The observed variation is consistent with adaptive divergence at multiple spatial scales along coastal Norway. Our findings suggest that local adaptation at a micro-geographic scale with high potential for gene flow is mainly attributable to blocks of tightly linked genes in the form of chromosomal inversions. We present the first experimental evidence for the putative adaptive functions of three large inversions that are polymorphic throughout the species range and show evidence of within-generation experimental selection against specific genotypes. These novel empirical investigations will aid our understanding of how climate change will affect the population dynamics and distributions of cod and other marine fishes and enable effective management of harvested species with high gene flow.
7. Pinto – Geckos
The Gamble lab studies the evolution of sex chromosomes, using gecko lizards as a model system. However, my work focuses how reproductive isolating barriers act within hybrid zones to maintain species-integrity during speciation. Thus, my dissertation has emphasized utilizing our labs extensive tools and knowledge of sex chromosomes to better elucidate the hypothesized link between speciation and sex chromosomes. To date, I have characterized the first stable hybrid zone in geckos, within the genus Sphaerodactylus. Currently, we have generated a draft genome of S. townsendi (see below), which has provided some preliminary insight into the sex determination system in Sphaerodactylus. For instance, it appears as though the sex chromosome in these geckos is homologous to chromosome 3 in chicken. Indeed, thus far we have deciphered some information about both speciation and sex chromosomes. However, the purpose of this grant is to provide the means to link these two investigations, elucidating novel insights into the processes of speciation and sex chromosome evolution.
8. Ward – Oak gall wasps
The overall goal of my PhD research is to determine the mechanisms that drive and maintain diversity within oak gall wasps, a speciose but largely under-studied group of phytophagous wasps. As their name implies, these wasps induce the formation of a wide range of galls, or abnormal swellings, on oak trees. Each species of gall wasp forms a unique gall structure, typically on a particular tissue type of a specific set of oak tree hosts. In some cases, similar galls on different oak hosts are formed by different gall wasp species. Most species of gall wasp also exhibit alternation of sexual and asexual generations, with each generation forming a distinct gall structure. Using a large (>23,000 galls) collection of gall wasps reared from galls collected across the eastern United States, I hope to determine not only how such a wide range of gall structures has evolved, but also how factors such as life history, gall type, host tissue exploited, and host species attacked are related to patterns of divergence in the group. Considering the typically tight host associations, I am also interested in how host shifts, a common driver of divergence in insects, may have influenced the evolution of oak gall wasps.
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