Guo Jianfang, born in June 1956, is an academician of the Chinese Academy of Sciences and the Academy of Sciences for the Developing World. He previously served as the director of the Institute of Hydrobiology at the Chinese Academy of Sciences and the director of the State Key Laboratory of Freshwater Ecology and Biotechnology. Currently, he holds positions as the vice chairman of the China Zoological Society, the chairman of the Fishery Society of China, and the vice chairman of the Chinese Society of Fisheries.
In his laboratory at the Institute of Hydrobiology, Chinese Academy of Sciences, located on the banks of Donghu Lake in Wuhan, Hubei Province, 68-year-old Guo Jianfang is conducting artificial breeding experiments with carp, guiding research personnel.
As a genetic breeder specializing in fish, Guo Jianfang has long been dedicated to research in developmental genetics and biotechnology related to fish breeding. The common carp, commonly seen on Chinese dining tables, is one of his primary research subjects. Over the past 40 years, he has led teams to cultivate four high-quality aquatic new varieties and has been granted more than 10 patents. His work has provided more delicious options for the Chinese people.
Born in a small village in Huangmei County, Hubei Province, in June 1956, Guo Jianfang grew up near Longgan Lake, where fishing was a primary livelihood for local residents. However, fish yields were not stable. The idea of improving fish harvests had long been in Guo Jianfang's mind.
In March 1978, Guo Jianfang became one of the first batch of college students after the resumption of the college entrance examination. He studied biology at Wuhan University and obtained both his bachelor's and master's degrees, studying under the renowned geneticist Professor Yu Xianjue, focusing on the chromosomal karyotypes of freshwater fish.
"Chromosomes are carriers of genetic material and play a significant role in the phenotype, gender, health, and offspring of organisms," Guo Jianfang said. At that time, he studied more than 30 species of freshwater fish with his teacher and found that the majority of fish species had 48 or 50 chromosomes in their somatic cells, known as diploid fish, which produce both male and female offspring.
When observing the silver carp under a microscope, he discovered a new phenomenon: these fish had 162 chromosomes in their somatic cells, then known as triploid fish. Their eggs did not undergo halving of chromosome number during reproduction, exhibiting characteristics of "unisexual female nucleus reproduction."
At that time, Jiang Yigui, director of the Genetics and Breeding Research Laboratory at the Institute of Hydrobiology, Chinese Academy of Sciences, had already discovered this phenomenon and began breeding experiments with carp. After graduating from Wuhan University in 1984, Guo Jianfang, who was deeply interested in the genetic characteristics of silver carp, joined Jiang Yigui's research group.
"According to the views of foreign scholars, offspring produced by this mode of reproduction should all be female fish. However, in nature, there are indeed some male individuals," Guo Jianfang said. What are the determining factors for sex? Why does the silver carp exhibit such characteristics? To answer these questions, it was necessary to understand the characteristics and distribution of carp germplasm resources in China.
Starting in 2010, over a period of three years, Guo Jianfang led his team to collect samples from all over the country, visiting over 50 sampling points in more than 40 rivers and lakes. They collected over 5,000 samples of carp. Upon returning, the team extracted genetic material samples and conducted gene sequencing, using theories and techniques from molecular biology and developmental biology to systematically study the genetic basis and reproductive mechanisms of silver carp, revealing for the first time the unique multiple reproductive methods of silver carp.
"Unisexual reproduction is usually considered an evolutionary 'dead end,' but silver carp exhibit strong genetic diversity and environmental adaptability," Guo Jianfang said. After many years of research, he first proposed the concept of "double triploids." These findings and research results laid the theoretical foundation for the systematic and precise breeding of superior varieties of silver carp.
Overcoming breeding challenges to increase carp production
At Fuer Aquatic Seedling Co., Ltd. in Huangshi City, Hubei Province, staff spread feed into fish ponds using machines. "Under the guidance of Professor Guo, we are breeding and promoting the new variety of carp, 'Zhongke No. 5.' This variety has increased disease resistance by more than 20% and significantly increased production," said Li Jianbing, the company's general manager.
As a leading local aquaculture company, Fuer Aquatic Seedling has collaborated with Guo Jianfang's team to establish an "Academician Expert Workstation" and conduct artificial breeding and seedling cultivation experiments for varieties such as "Zhongke No. 3" and "Zhongke No. 5." They produce over 500 million fish fry annually. The company has become a pilot breeding base for genetic breeding at the Institute of Hydrobiology, Chinese Academy of Sciences.
China is one of the world's leading producers of aquatic products, maintaining the world's highest aquaculture output for over 30 years. However, according to Guo Jianfang, further efforts by researchers are needed to cultivate superior varieties and ensure that people not only have enough to eat but also eat well.
The unique genetic characteristics of silver carp provide conditions for the selection and breeding of new varieties. "Breeding new varieties is a long and arduous process. First, we need to select parent fish with strong physique and distinct characteristics for breeding. With each generation, we select the most ideal offspring as breeding fish, and through generations of cultivation and purification, we finally achieve the desired 'improvement rate,'" Guo Jianfang said. This process may take 10 years or even decades.
Over the past decade, Guo Jianfang has led his team to use modern biotechnologies such as molecular markers, molecular modules, and designed varieties to cultivate new varieties such as "Zhongke No. 3," "Zhongke No. 5," and Changfeng carp. With everyone's efforts, the national carp production has increased from 48,000 tons in 1983 to 2.784 million tons in 2021.
Guiding farming practices to serve industrial development
"While crucian carp (a colloquial term for carp) is delicious, it has too many small bones. Is there a solution?" "We have used gene editing technology to breed over 200 triploid silver carp without intermuscular bones in the laboratory. Currently, relevant evaluations are underway. In the future, I believe everyone will be able to enjoy boneless carp," not long ago, at the "Academician Guo Jianfang Natural Science Popularization Studio" in Liberation Park, Wuhan, Guo Jianfang was giving a science popularization class to some citizens and schoolchildren, patiently answering their questions. In 2013, Gui Jianfang was elected as an academician of the Chinese Academy of Sciences. As a leading figure in the field of fish cell engineering widely recognized in the industry, Gui Jianfang shoulders even greater responsibilities. Alongside his research and teaching duties, he actively engages in various science popularization and education activities, while also providing guidance on aquaculture techniques in different regions. In Huangshi City, he helped aquafarmers address low survival rates among fish fry; in Yangzhou City, Jiangsu Province, he guided local aquafarmers in breeding new varieties of yellow catfish, thereby boosting their income... As of now, Gui Jianfang has trained over 5000 aquafarmers, ensuring that scientific research outcomes better serve the industry.
"Apart from explaining profound scientific knowledge and research findings in simple and understandable language, Academician Gui has rallied more than 50 experts and scholars from universities and research institutes to participate in popularizing knowledge about natural ecology. Over the past three years, nearly a hundred events have been organized," said Tang Wen, Director of Ecological Restoration Department at the Wuhan Municipal Bureau of Parks and Forestry. These popular science lectures and activities are almost always fully attended and are greatly beloved by the general public.
Since 1989, Gui Jianfang has been dedicated to graduate education at the Chinese Academy of Sciences for over 30 years, teaching courses such as "Fish Genetics and Breeding," "Developmental Biology," and "Aquatic Genetics and Breeding." He has also edited multiple monographs and graduate textbooks. Under his influence and leadership, generations of aquatic researchers have rooted themselves in national needs, continuously advancing the high-quality development of aquaculture breeding.
■ Journalist's Note Striving to provide more and better aquatic food For over 40 years, Gui Jianfang has been tirelessly exploring the field of fish genetics and breeding, seeking ways to increase the production of fish such as crucian carp, and striving unremittingly to realize the Chinese people's "freedom to eat fish."
Fish and other aquatic products are important sources of high-quality protein for the human body. Especially for commonly cultivated freshwater fish like crucian carp, they have become the mainstay of freshwater aquaculture in China, making outstanding contributions to ensuring stable food supply. In recent years, China's aquaculture production has consistently accounted for about two-thirds of the world's total, providing over one-third of the animal protein sources for domestic consumers.
In Gui Jianfang's view, adopting a perspective of "big food," demanding food from rivers, lakes, and seas, prioritizing ecology, and promoting the green development of aquaculture are crucial. It is necessary to focus on the protection and cultivation of excellent germplasm resources. Aquatic researchers should continue their efforts, utilizing technological means to address issues of increasing fishery production and aquafarmers' income, accelerating the transformation and upgrading of China's fisheries, and providing more and better aquatic food for over 1.4 billion Chinese people.
