Meeting Abstract

P1-40   -    Acute Salinity Response of a Leuresthes tenuis Embryonic Cell Line Corona, MM*; Kueltz, D; University of California, Davis; University of California, Davis mmcorona@ucdavis.edu

The California grunion, Leuresthes tenuis, provides a unique opportunity to study how coastal species may respond to future climate change induced alterations in the global hydrological cycle. The adults of this species oviposit past the tideline during summer full and new moons. Embryos incubate emerged from water until the next high tide, exposing L. tenuis to environmental fluctuations during this vulnerable life stage. Studies on their physiological limits and responses to alterations in their environment can lead to critical insights on how climate change may impact this species’ fitness. However, the acute osmotic stress response of L. tenuis has not been widely explored. This project sought to identify the critical osmolality threshold for acute salinity exposure in an immortalized embryonic California grunion cell line. The identification of this threshold allows for the establishment of a cellular salinity tolerance range for the embryos, as well as the opportunity to distinguish what molecular mechanisms are utilized in osmotic stress response. Replicates of the cell line were exposed to media of different salinities, ranging from 300 milliosmole (isosmotic conditions) to 800 milliosmole (hyperosmotic conditions) for 96 hours. Confluency and overall cell death percentage was estimated each day. On the final day, cells were triple stained with plasma membrane, mitochondria, and nucleus targeted dyes, and imaged to note any differences in cell morphology among the treatments. Cells were also counted using a hemocytometer to account for any over-confluency seen in the lower exposures. Additional replicates were allowed to grow to confluency to note how osmotic stress alters long-term proliferation patterns. The results of these experiments will be discussed in the context of stress effects on cellular and molecular phenotypes. Funded by NSF-IOS 1656371 and BARD IS-5358-21.