Auburn University researchers mapped the genome of blue catfish for the first time
A research team from Auburn University, from the College of Veterinary Medicine and the College of Agriculture, recently became the first to map a high-quality blue catfish genome assembly.
The genome published in the journal GigaScience, is essential for genetic improvement through gene editing or genome-assisted selection and will contribute to the genetic improvement of better catfish breeds for the multi-million dollar catfish farming industry.
Catfish farming is the largest aquaculture industry in the US, accounting for about 70% of the country’s total production. Mississippi, Alabama, Arkansas and Texas account for the bulk of the total freshwater catfish production in the US, with Alabama ranking second to Mississippi. The primary fish used for breeding purposes is a hybrid made by breeding male blue catfish with female channel catfish.
“The hybrid catfish is superior in terms of growth and disease resistance,” said Xu Wang, an assistant professor of comparative animal health genomics in the Department of Pathobiology at the College of Veterinary Medicine and an associate professor at the HudsonAlpha Institute for Biotechnology. He is one of the leaders of the project.
“Faster growth means more profit. Originally, farmed fish were mainly channel catfish, but three major bacterial pathogens led to a 40% production loss and annual economic damage of over $100 million in the US industry alone,” Wang said. “The hybrid mix of blue and channel catfish improved disease resistance and reduced mortality by half.”
Even so, Wang said, there is a critical need for further genetic improvements using genomic methods.
“The channel catfish genome was mapped by John Liu’s lab in Auburn (he’s now at Syracuse University) in 2016, but the blue catfish genome wasn’t available until we published it,” Wang said. “Our high-quality blue catfish genome fills the urgent needs to meet the long-term goal of improving growth, feed efficiency, stress and disease resistance, and reproduction.”
Wang was senior author of the GigaScience paper, assisted by Haolong Wang (not related), a graduate student in biomedical sciences who was supported by both an Auburn Presidential Graduate Research Fellowship and a College of Veterinary Medicine Dean’s Fellowship. The veterinary researchers worked closely with a team from the College of Agriculture’s School of Fisheries, Aquaculture and Aquatic Sciences, led by Professor Rex Dunham, an internationally recognized authority on catfish genetic enhancement and gene editing.
“This is a fantastic step forward,” Dunham said of mapping the blue catfish genome. “There have been many genetic improvement projects related to gene transfer and gene editing that would not be possible for blue catfish without them. As a result, we couldn’t work in parallel with what we’re doing with channel catfish. Since a hybrid between channel and blue is the best genetic type for the catfish industry, this also limited what we could do with these tools to improve the hybrid.
“That roadblock is gone now,” Dunham said. “The available blue catfish genome opens up a huge treasure trove of markers that we can use for other approaches, such as Thanks to this research, we are much less constrained than before.”
This story originally appeared on Auburn University’s website.