A library, but for mutant water fleas

UTA biologist to help create open-access library of mutant water flea DNA

Thursday, Dec 01, 2022 • Linsey Retcofsky : Contact

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A biologist at The University of Texas at Arlington is leading an effort to establish an open-access library of gene knock-out mutants for the water flea genus Daphnia.

Sen Xu, associate professor of biology, and Michael Pfrender, professor and director of the Genomics & Bioinformatics Core Facility at the University of Notre Dame, have received a four-year, $2.2 million grant from the National Science Foundation to create 1,000 gene knock-out mutants to advance scientific understanding of the biological functions of individual genes of the water flea.

Daphnia knock-out mutants are created by removing one single gene from the crustacean’s DNA using CRISPR-Cas gene-editing technology. Removal of an individual gene allows researchers to better understand that gene’s role in normal biological processes.

The water flea genus Daphnia is an emerging model for genomic research, trailing other well-established animal systems such as mice, fruit flies and worms. Xu said the techniques for manipulating Daphnia’s genes are underdeveloped.

“With this collection of mutants, we hope we can bring research on Daphnia to an entirely new level,” Xu said. “We will make it a community resource, and the mutants will be available to scientists around the world.”

As they are very sensitive to contaminants, water fleas are important indicators of ecological health. Scientists often use them to monitor water quality in freshwater systems.

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Sen Xu

“Humans and water flea share many genes, and those genes may perform the same function in both species,” Xu said. “How Daphnia respond and deal with environmental stressors in freshwater ecosystems may have important implications when we examine how humans could respond to similar stressors.”

Xu’s lab will use CRISPR gene-editing technology to make the water flea mutant lines, and Pfrender’s lab will sequence the mutants’ genomes. More than 20 partner labs will help test the mutants’ phenotypic changes. Notre Dame and UTA collaborators will work together to create the online database that will be freely available to the research community.

“Scientists will be able to request the mutant they need to study the gene they are interested in, and we will ship the materials directly to their labs,” Xu said.

In addition to supporting the research and development of the mutant database, the grant will fund public workshops in Daphnia gene editing, which will be free of charge to the participants.