Integrative Biology | Meyer Lab

Natural populations of marine invertebrates vary widely in adaptive traits such as growth rate and tolerance of abiotic stress. Our research is directed at understanding the functional basis of this variation and its responses to selection.

In search of the genomic basis for adaptive variation in thermal tolerance of corals

In Orbicella faveolata, some genotypes bleach in controlled thermal stress treatments (bottom panels) while others remain healthy (top panels)

Reef-building Scleractinian corals are threatened by rising sea surface temperatures resulting from climate change. This has naturally brought the study of thermal tolerance to the forefront of coral biology. Although thermal tolerance is known to vary both between and within species, the functional basis of this variation remains unknown. Our research combines quantitative genetic and genomic approaches to quantify the contribution of genetic factors to variation in stress tolerance, and identify the genomic regions underlying this variation. Ultimately, we aim to identify the mechanistic basis of adaptation to thermal stress in corals, in order to understand the consequences of climate change for corals and the diverse ecosystems they support.

At OSU we have developed transcriptomic resources for several coral species, and have established a saltwater aquarium facility for long-term maintenance of corals. We are currently developing genomic resources for the Caribbean coral Orbicella faveolata and the Arabian/Persian Gulf coral Platygyra daedalea, and using sequencing-based approaches to identify genetic markers and genes associated with variaton in these corals' thermal tolerance.

Genomic determinants of growth in oyster aquaculture

Variation in growth rates among larvae of the Pacific oyster (Crassostrea gigas) can be easily measured from the shell length of preserved veliger larvae, shown here.

Growth rates and stress tolerance relevant for selection both in the natural pelagic larval phase and in breeding programs for aquaculture production. We study the genetic factors contribution to these phenotypes in the Pacific oyster (Crassostrea gigas), a widely farmed aquaculture species with a cosmopolitan distribution.

One genetic factor contributing to this variation is growth heterosis, the positive relationship between growth rates and multi-locus heterozygosity studied for half a century in bivalve molluscs. Despite the economic importance of this phenomenon for many crops, its molecular basis remains poorly understood. We study this phenomenon using controlled crosses to compare fast-growing hybrid larvae with inbred larvae from the same parental lines. Our preliminary results at OSU support previous observations of balanced ribosomal protein expression in fast-growing hybrids.

In collaboration with Langdon and Waldbusser labs at OSU, we are also studying selected families maintained as part of the Molluscan Broodstock Program to compare their performance in the increasingly acidified conditions that have caused extensive larval mortality in hatchery production throughout the Northwest.

Developing a Systems Biology perspective on responses to climate change

The aggregating anemone (Anthopleura elegantissima) associates with green algal symbionts (Elliptochloris marina, bottom panel) or dinoflagellates (Symbiodinium, top panel) in different habitats.

Climate change is driving rapid changes in the abiotic conditions of coastal marine ecosystems, prompting extensive efforts to understand and predict the consequences of these changes for organisms living in these habitats. However, existing studies have largely focused on patterns and mechanism at a single level in of biological organization. We are working with an interdisciplinary group of researchers in Integrative Biology and other departments at OSU (SSIMBIO) to develop a systems biology perspective on interactions between different components that lead to emergent properties of the system. We aim to extend the systems approach across levels, from genes to ecosystems, to understand the consequences of climate change for coastal marine ecosystems.

We are focusing on the symbiotic anemone, Anthopleura elegantissima, as a model for the applying the systems approach to study biological responses to climate change. This intertidal species occurs in a dynamic patchwork of conditions throughout the eastern Pacific, and engages in different symbiotic associations depending on local conditions.

In collaboration with the Weis lab, we have developed an annotated transcriptome database for this species. We are currently profiling gene expression in an extensive collection of samples from different latitudes and tidal heights, and developing integrated genomic resources to enable genomic studies of adaptation and divergence in this system.