EAPSI: Changes in Gene Expression of the Lined Seahorse, Hippocampus Erectus, in Response to Temperature Stress

Johnson Cara A, Melbourne FL

Investigators

Abstract

Seahorses (Family: Syngnathidae) are one of the most intriguing and recognizable groups of fishes, with unique life history traits, morphologies, and cultural importance. Natural seahorse populations are strained, not only because they are directly targeted for display and medicinal uses; they are also extremely vulnerable to many other threats in their environment, exacerbated by their unique life histories. Seahorses are generally monogamous, are poor swimmers, have limited dispersal ability and small home ranges, and are distributed in small patches. These factors restrict seahorse responses to the unpredictable effects of global climate change. The proposed project will examine the response of the heat shock protein Hsp70 to increasing temperature in the lined seahorse, Hippocampus erectus. This work will be conducted under the mentorship of Dr. Qiang Lin, whose group sequenced the seahorse genome, at the Chinese Academy of Science Key Laboratory of Tropical Marine Bio-resources and Ecology in Guangzhou, China. The experimental model developed under this project will subsequently be applied to other seahorse and pipefish species to offer a more complete picture of cellular stress response in the Syngnathidae family. The lined seahorse, Hippocampus erectus, is listed as vulnerable by the International Union for Conservation of Nature (IUCN) and is native to the South China Sea. With the completion of the Seahorse Genome Project by Dr. Qiang Lin?s laboratory in Guangzhou, China, there is now an encyclopedia of functional genes with which to compare tissue samples and determine an individual seahorse?s transcriptome. In an effort to understand how chronic and acute temperature stress will affect these organisms, liver and muscle tissue samples will be collected from groups of H. erectus that have been maintained at set constant temperatures, as well as from separate groups that have been exposed to acute heat shock for varying periods of time. Transcriptome analysis will be performed following extraction of mRNA and synthesis of cDNA from each tissue sample to determine the changes in gene expression between different heat stress events. These findings will assist the development of management plans for these threatened species, by providing a better understanding of how the cellular stress response mechanism of these animals will respond and adapt to warming oceans. Seahorses are often used as indicator species of the health of an ecosystem, and the information gained from this research can better direct the use of syngnathids as a representative focal species for dispersal-limited populations. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Ministry of Science and Technology of China.