Researchers develop boneless carp variety

People eating a variety of carp will not have to worry about getting tiny bones stuck in their throats in future thanks to researchers at the Chinese Academy of Fishery Sciences' Heilongjiang Fishery Research Institute who have cultivated the world's first crucian carp lacking intermuscular fish bones.

Academicians, including teams of experts led by Gui Jianfang from the Chinese Academy of Sciences and the CAFS' Chen Songlin, examined the new variety at the institute on Jan 14.

They validated the new variety, which was created by gene-editing techniques, Science and Technology Daily reported.

Crucian carp is a popular freshwater fish with tender meat and a fresh flavor, but its many tiny bones make it difficult to eat or process industrially.

It is a member of the cyprinid family, the most numerous of the vertebrate families.

A research team at the institute started a project to tackle the problem in 2009 and identified the key gene, from 1,600 candidate genes, to control the growth of the fish's intermuscular spine.

After a decade of research, the team created the mutant population of crucian carp through gene-editing techniques, with a heritable population of the new variety achieved last year.

The new variety grows well and is superficially indistinguishable from normal crucian carp.

The expert teams said its creation is a major breakthrough in improving the quality of carp varieties and will boost the consumption of aquatic products.

They urged biologists to continue conducting basic research and promote industrialization so that people will no longer have to pick out fish bones.

Another research team at Huazhong Agricultural University has found the key gene that controls the development of intermuscular fish bones in Wuchang bream, another species of cyprinid that is native to water bodies throughout the Yangtze River Basin, the university announced on its WeChat account late last month.

Professor Gao Zexia, the leader of the research team at the university, said she decided to study the subject in 2012.

"Many people have swallowed fish bones and got them stuck in their throats, so I wanted to cultivate a boneless fish variety that can be a future trend for the fish industry," Gao said.

Her team found the first fish bone gene expression and obtained a patent.

They spent seven years using gene-editing techniques to test 50 gene candidates on zebra fish, a fast-growing cyprinid, by removing the genes one by one and observing the growth and changes in fish bones.

Gao said the team found an effective gene able to reduce fish bones by 70 percent in 2018 but it was not the key gene that would ensure bream grew no intermuscular bones at all.

That was finally discovered in 2019, with hundreds of zebra fish and their offspring all proving to be boneless fish. The key gene is common to all fish with bones, she said.

After finding the key gene, researchers transplanted the gene into boneless fish to see if they would grow bones again, reaffirming the key gene's function.

The removal of the key gene has been tested on Wuchang bream, grass carp and crucian carp.

"I believe that the boneless domestic fish will lead to an upgrade of the freshwater fish industry and family diets," Gao said.