As the "main force" of large-scale freshwater aquaculture in China, crucian carp has tender meat and is rich in nutrition. However, the more than 80 intermuscular spines (commonly known as "small spines") in its body make consumers both love and fear it.
These hair-thin spines not only pose a high risk of choking but also restrict the development of the deep processing industry of crucian carp. Due to the large number of spines, foods such as fish balls and fish cans are difficult to be produced on a large scale, and their market potential is severely suppressed.
A team led by GUI Jianfang, an academician of the Chinese Academy of Sciences and a researcher at the Institute of Hydrobiology, has created a new variety of silver crucian carp that is both free of intramuscular spines and infertile by combining "non-meiotic fusion" reproduction with gene editing technology.
This new variety, known as "intermuscular spiny heterozygous silver carp", has a more common name - "spiny crucian carp".
It not only solves the problem of finding bones when eating fish, but also brings multiple advantages. The research team introduced that thornless crucian carp can swim and grow normally, and their taste is exactly the same as that of ordinary crucian carp.
Meanwhile, since this kind of fish is infertile, even if it escapes from breeding, it will not cause ecological risks. This design not only meets consumers' demands but also protects the ecological balance.
It is not an easy task to transform a crucian carp. Scientific research has found that if only one partial homologous gene is knocked out, the development of intermuscular spines is not affected. Only by simultaneously knocking out two partial homologous genes and their six alleles can a silver crucian carp mutant with complete absence of intermuscular spines be created. This complex gene editing process demonstrates the precision and efficiency of modern biotechnology.
This research is one of the achievements of the A-class pilot Project of the Chinese Academy of Sciences, "Precision Design and Creation of Seeds", marking that China's agricultural breeding is fully transitioning from "selection based on weather conditions" to the "precision design" era that is predictable and programmable.
The "Zhongke No. 6" boneless crucian carp not only has the feature of bone removal, but also has achieved significant improvements in multiple production performances. Compared with traditional crucian carp, its growth rate has increased by an average of 25.0%, the average survival rate in breeding has increased by an average of 66.5%, the average feed efficiency has increased by an average of 20.1%, and it also has a strong tolerance to herpesviruses.
In a recent lecture, Academician GUI Jianfang stated: Currently, this variety is undergoing large-scale artificial breeding and will soon be available on the dining tables of the general public.