China creates boneless crucian carp

The research team at CAS on December 23 announced the successful creation of Zhongke 6 – a Gibel crucian carp variety that is healthy and boneless, suitable for meals. This is the result of a 6-year effort in the “Precision Design and Breeding” program implemented by CAS.

The crucian carp is popular with many people because of its soft, nutritious and protein-rich meat, but is notoriously difficult to eat because it has more than 80 small Y-shaped bones located between the muscle fibers. To handle it, the research team from CAS decoded their complex genetic map and identified runx2b – the “architect” gene that guides the body to develop bone chips.

Because Gibel crucian carp has many sets of chromosomes, the research team had to use the CRISPR-Cas9 gene editing technique, which acts as “molecular scissors”, to perform precise intervention. They cut out genes at the embryonic stage, thereby removing the “instructions” for bone development. This ensures that the biological system for the approximately 80 ossicles is never activated, while the fish’s main skeleton still develops normally.

Zhongke No. 6 is optimized with three outstanding characteristics including high productivity, good disease resistance in dense aquaculture environments and requires less feed while still producing the same amount of high quality protein.

Theo Interesting Engineeringbone chips are a common cause of food-related emergencies because their small size, sharp tip, and Y-shape make them difficult to detect while chewing. When swallowed by humans, bone chips can get stuck in the throat or esophagus, causing sharp pain and discomfort. In severe cases, they can perforate the lining of the digestive tract, leading to infection or requiring surgery to remove.