Gene-edited Carp Fish is Rid of Tiny Y-shaped Bones

Carp fish is a delicious and nutritious food source in Asia. People loved its taste and protein, but they hated picking through tiny, Y-shaped bones. Diners picked, scraped, and occasionally choked. 

But thanks to science, this problem has now been solved. Researchers from the Chinese Academy of Sciences (CAS) in Beijing, China have reportedly created a fish without minute bones using gene-editing tools. Scientists identified runx2b as the specific gene responsible for the growth of these 80+ troublesome spines. 

The edit is highly targeted; the fish’s main skeleton remains intact for healthy development, but the miniscule intermuscular bones never form. The genetic tweak is purely structural; the fish retains its signature tender texture and rich, savory flavor. 

Commonly known as the Prussian carp, the Gibel carp (Carassius gibelio) is a tough, medium-sized freshwater fish related to both goldfish and minnows. It is widely eaten across China. While carp is celebrated for its tender meat and high protein content, it is famously difficult to eat. Its main drawback is the presence of over 80 tiny, Y-shaped intermuscular bones embedded in the muscle, making every bite a tedious chore. 

Moreover, 80+ tiny spines make industrial processing difficult, severely limiting the market potential of this popular species. 

China Global Television Network reported that the CAS team led by academician Gui Jianfang successfully genetically edited the “Zhongke No. 6” breed. To create this bone-free variety, scientists first mapped the carp’s complex genome. 

This led to the identification of two versions of a specific gene in the Gibel carp: Cgrunx2b-A and Cgrunx2b-B. These genes are the main culprits behind the formation of those pesky intermuscular bones. 

Given the carp’s complex genetic makeup, the team used CRISPR/Cas9 “molecular scissors” to perform a surgical strike, precisely snipping the genes responsible for bone growth. In particular, they edited all copies of both genes simultaneously. It disabled this gene during embryogenesis and blocked the instructions for bone growth without affecting the rest of the fish’s skeletal development. 

The resulting mutants were completely free of intermuscular bones. They also created “IB-less” versions (with significantly fewer bones) by editing only some of the genetic alleles. 

The gene-edited variety is engineered for maximum efficiency through three key improvements. 

First, it offers a high yield, growing faster than traditional breeds, thereby increasing food production. Second, it possesses enhanced disease resistance, allowing it to stay healthy even in the crowded conditions of modern industrial fish farms. Finally, it is more sustainable, requiring significantly less feed to produce the same amount of high-quality protein, which reduces both costs and environmental impact. 

Fish bones are a leading cause of food-related emergency room visits because of their small size, sharp points, and “Y” shapes, which make them difficult to detect during chewing. When swallowed, these bones can become lodged in the throat or esophagus, causing sharp pain and a sensation of something being stuck. In severe cases, they can puncture the lining of the digestive tract, leading to infections or requiring surgical removal. 

This six-year endeavor, part of a strategic CAS research program titled “Precision Seed Design and Creation,” represents a triumph of genetic science and a direct answer to a very old problem.