CAREER: Alterations in Marine Bivalve Shell Formation by Environmental Stress

Shellfishes use shells to protect themselves from predators and obtain nutrients from the water. Shells are tough since the compounds in them are harder than rocks. However, the toughness of shells can be easily affected by environmental conditions during the shell formation. Shells can become fragile when the shell formation occursin adverse conditions, such as high carbon dioxide (CO2) level or low salinity in water. With the effects on shells, the production of some shellfish species with high market values, such as the oysters, will be possibly declined in the coastal areas. The research goal of this CAREER proposal is to understand how the CO2 and salinity of water modify the Eastern oyster shell formation from a genetic level so that a method to help the oysters overcome the environmental effects during the shell formation. The result of this study will be applied to oyster aquaculture in the Gulf of Mexico. The project will also help with restoration of shellfish habitats on the coast. In addition, the project will involve the training of students from historically underrepresented groups in science at Texas A&M University – Corpus Christi via the educational goals of the project. The project will also provides research opportunities to community college students, as well as research opportunities for middle/high school science teachers in the biological sciences. It is well known that the shell development during the early life stages of bivalves is vulnerable to environmental stressors, but there is little understanding of the genetic responses of bivalves to environmental changes during shell development. The research goal of this CAREER project is to determine the molecular mechanisms by which bivalve shell formation is altered under ocean acidification (OA) and salinity fluctuation. The proposed approach is to 1) characterize changes in oyster shells under the stress of OA and salinity fluctuation by measuring the shell morphological changes, analyzing changes in shell composition, and identifying changes in matrix protein production of the shells; 2) identify the signaling pathway for shell formation response to OA and salinity stress by conducting transcriptomic analysis and calcium imaging with the primary cell cultures from the mantle tissue of the Eastern oyster; and 3) enhance the tolerance of the Eastern oyster shell formation to the environmental impacts by creating mutagenesis and transgenic strains. The education goals of the proposed project are to increase diversity in higher education and biological research, focusing particularly on encouraging Hispanic/Latino students to pursue advanced degrees in STEM fields. The approach will be to 1) create an innovative class for undergraduate and graduate students that involves multiple off-campus experts and facilities in teaching and student-learning outcome assessment; 2) providing research opportunities to undergraduate students and community college students; and 3) organizing a summer biological science section for middle/high school students and a training section for elementary/middle school teacher education. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.