World Aquaculture Magazine - March 2024

WWW.WAS.ORG • WORLD AQUACULTURE • MARCH 2024 15 The Journal of the World Aquaculture Society (JWAS) JWAS is a scientific journal devoted to the advancement of technological innovations and solutions to major issues facing the growth of global aquaculture. For over four decades, JWAS has represented the part of the World Aquaculture Society’s overall mission. JWAS seeks manuscripts related to all aspects of ecologically, socially and economically sustainable production of all aquatic species worldwide. Learn more here. market value for human consumption and this amphibian species is now commercially cultured in many parts of the world. In China, amphibian aquaculture of the American bullfrog reached 500,000 tons in 2019. As with many cultured species, stress events associated with high-density culture increase the bullfrog’s susceptibility to aquatic pathogens, which can result in disease outbreaks. Several bacterial pathogens can cause a condition known as red-leg syndrome (RLS), and one of these pathogens (Citrobacter freundii) is known to cause high mortality in bullfrogs. Disease control is challenging and there is limited understanding of how immune responses or metabolic mechanisms change in bullfrogs in response to this or other infections. This study assessed gene expression profiles of bullfrogs after C. freundii infection to provide a baseline understanding of how various genes are regulated. RNA sequencing technology was utilized to determine the transcriptomic profile and identify differentially expressed genes (DEGs) from the liver and spleen of bullfrogs post-experimental infection with C. freundii. Following de novo assembly, 77,556 L. catesbeianus transcripts were generated and 49,421 of these genes were annotated. There were 1487 DEGs identified from analysis of liver tissue and 788 of these were upregulated and 709 were downregulated in response to infection. In spleen tissue, they found a total of 799 DEGs, and 311 of those genes were upregulated and 488 downregulated. Many of the DEGs were associated with immune response and metabolic pathways. It was speculated that bullfrogs may regulate immune-related and metabolism-related gene expression via some type of positive and negative feedback following infection, but the mechanism associated with this requires further study. This work is the first to present a large transcriptomic profile of the bullfrog immune response post-C. Freundii infection and the findings provide new insight into molecular mechanisms associated with disease defenses of the American bullfrog. — Ken Cain, Executive Editor, JWAS U.S. AQUACULTURE SOCIETY Sponsored Publications Request for Proposals The USAS is seeking proposals for publications, including books, conference proceedings, fact sheets, pictorials, hatchery or production manuals, data compilations, and other materials that are important to U.S. aquaculture development and that will be of benefit to USAS members. Individuals wishing to have a project considered for funding by the USAS should prepare a proposal — guidelines are available on the website • CONDITIONS FOR PUBLICATION: The USAS Board of Directors will rate proposals and select projects for publication. The successful applicant will serve as co-author; however, depending on contribution to the publication, the applicant may not necessarily serve as chief or sole author. The USAS will cover general publication and distribution costs for one or more projects up to $5,000 each year. However, special consideration will be given to worthwhile projects that exceed this limit. No compensation will be provided to the authors for their time spent in writing the publication. The publication will be property of the USAS and will be sold through the WAS bookstore. • CONTACT: John Bowzer, Ph.D. • EMAIL: John.Bowzer@ADM.COM • PHONE: 217-451-3963 • MOBILE: 985-377-4480