Gene Editing Produces First G0 Population of Pacific Abalones
Researchers at the Chinese Academy of Sciences developed an isolated rearing method to overcome high larval mortality in mollusks.
Marine biologists at the Institute of Oceanology of the Chinese Academy of Sciences have produced a founder generation of roughly 100 genome-edited Pacific abalones. The biological innovation establishes a complete rearing workflow that keeps mutated larvae alive through metamorphosis into juvenile shellfish.
Isolating larvae to halt protist outbreaks
Genome-editing techniques like CRISPR/Cas9 have advanced across commercial aquaculture, but marine mollusks have remained difficult to modify through this genetic innovation. The obstacle was rarely the gene-editing step itself. Instead, young larvae carrying mutations consistently died before completing metamorphosis. In conventional small-volume culture systems, sudden outbreaks of single-celled protists routinely wiped out entire batches within days, according to a report published by Phys.org.
To solve this vulnerability, researchers at the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) separated individual larvae into single wells. The team referred to these individual culture compartments as single apartments. By isolating each organism and optimizing the chemical and environmental cues that trigger transformation, the team pushed larval survival rates past 90%.
“The individual-level verification provided an early 'identity verification' of the edited animals. It also helped confirm that mutated larvae had developed into mutated juveniles.”
— Yu Yanan, Institute of Oceanology of the Chinese Academy of Sciences
Targeting shell formation and juvenile diet
The experimental team targeted Hdh-tyr1, a tyrosinase gene that plays a direct role in shell formation in the Pacific abalone (Haliotis discus hannai). After inducing the targeted mutations, the researchers moved the surviving specimens onto specialized nutrition to support their transition into juveniles.
The researchers identified three benthic diatom species that served as high-quality feed for the newly transformed abalones. This diet supported steady shell growth. The largest individuals in the resulting G0 founder population reached shell lengths of approximately 3 centimeters (1.2 inches), with soft bodies visible through the respiratory pores of their shells.
Early genotyping verifies genetic changes
Confirming whether mutations carried through physical metamorphosis required new analytical methods. Because young abalones are fragile and minuscule, standard tissue sampling risked killing them or yielding insufficient material. The IOCAS team designed a simplified DNA extraction protocol to test the tiny specimens without destroying the batch.
First author Yu Yanan explained that this early identification step proved indispensable for the program. The process confirmed that the genetic edits introduced at the single-cell stage persisted into the juvenile shellfish. Corresponding author Professor Huan Pin noted that the integrated workflow covers editing, larval housing, metamorphosis induction and genotyping, establishing a reproducible technical pipeline for mollusk breeding and opening new avenues for intellectual property in marine biotechnology.
Read also on The Patent: Soil Bacterium from Iran Yields Two New Chemical Compounds · SmartPE Boosts Prime Editing in Dicot Crops
