Tong Di Zhou: Famous biologist

Source: Xinhua News Agency

Tong Di zhou, zi Weisun, a native of Yinxian County, Zhejiang, is a Chinese embryologist and developmental biologist. Born on May 28, 1902, died in March 1979. He graduated from the Department of Biology of Fudan University in Shanghai in 1930 and received his Ph.D. from the University of Brussels in Belgium in 1934. He has served as the teaching, scientific research and administrative leader of Shandong University, the Institute of Oceanology and the Institute of Zoology of the Chinese Academy of Sciences, the director and vice president of the Biology Department of the Chinese Academy of Sciences, and the vice chairman of the National Committee of the Chinese People's Political Consultative Conference. He joined the Communist Party of China in 1978. One of his major contributions was the experimental study of the development of Wenchang fish in the 1950s and early 1960s.

Due to the status of Wenchang fish in classification, its embryonic development has always been valued. In the past, it was considered that its development belonged to the mosaic type, and if a part of it was missing, it could not be supplemented by adjustment. He used methods such as isolation and replacement of the splitting ball to prove that the development fate of the early embryonic division ball of Wenchang fish has a certain degree of plasticity. Moreover, the dividing spheres belonging to the 3 germ layers can be transformed into each other to varying degrees through cell-to-cell interactions under experimental conditions. In addition, he also found that the embryonic development of Wenchang fish has a similar induction effect as that of vertebrates. These studies have revealed the consistency of the developmental mechanism between Wenchang fish and vertebrates, thus demonstrating the important position of Wenchang fish in the evolution from invertebrates to vertebrates.

In the early 1960s, he applied the technique of cell nucleus transplantation to transplant the nuclei of goldfish into the eggs of nucleated mackerel, and found that the early traits of juvenile fish after nucleation seemed to be based on cytoplasm. He transplanted carp nuclei into the nucleated crucian carp fertilized eggs and found that some of the traits of the eggs were somewhat between the two fish when they developed into adults. Both of these conditions show the influence of the cytoplasm of the egg on trait formation, and he also found that the nucleus of the goldfish is transplanted into the eggs of the mackerel, and then moved back to the fertilized eggs of the goldfish after a certain period of development, which can sometimes produce the traits of the hybrid embryos of the mackerel and the goldfish, and it is likely that the goldfish nucleus stays briefly in the cytoplasm of the mackerel and is also affected in some way.

He had envisioned breeding by transplanting nuclei: combining the advantages of two fish that could not be hybridized and passing them on. His research proposes a new and possible approach to animal breeding. His research on sea squirts was mainly conducted before the 1950s. His research proved that some tissues and organs in embryonic development are plastic, correcting the view that some scholars in the past believed that its development belonged to the strict mosaic type. From the 1940s to the early 1950s, his experimental studies of early development of fish also demonstrated that after the eggs were fertilized, the protoplasm flowed to the animal pole, and its tissue centers were established shortly after fertilization. This phenomenon may have universal significance in the development of vertebrates. During this time, his research on ciliary motility in amphibian embryos determined the dependence of ciliary motility direction on mesodermal tissues, which may have effects through chemicals, and thus he explored the polarity of embryonic tissue.

After the 1970s, Tong Began to pay attention to the study of nuclear-mass relationships using biochemical methods. He and his collaborators also studied the mutagenesis of nucleic acids on goldfish traits, achieved many results, and published papers. His scientific work has always been through a thread, that is, from the structure of the egg before and after fertilization to the interrelationship between cytoplasm and nucleus in development, and then to explore the role of cytoplasm in trait inheritance.