Carlo Jucci

Carlo Jucci (28 June 1897 in Rieti – 22 October 1962 in Rome)

An important contribution by Jucci were his studies on the silkworm, whose metabolism he investigated comparing larval growth among several races of the moth, thus opening a new chapter in the comparative physiology. Jucci was also interested in biochemical genetics and he directed his attention especially to the silkworm cocoon color. His studies concerning the migration of leaf pigments and differential permeability of the intestine, and silkworm salivary gland function on carotenoids and flavones were the first example of biochemical genetics in the animal world.

Education and career Following a course in classical studies Jucci graduated in natural sciences from the University of Rome on 10 July 1920, defending his thesis on the biology of termites.

In 1927 a grant from the Rockefeller Foundation, allowed him to travel to, and work in the USA, at the Marine Biological Laboratory near Plymouth, Massachusetts. Here, Jucci conducted research on cell permeability and ciliary movement in Actinia. He returned to the Institute of Physiology at the University of Naples the following year, seconded to the Zoological Station. He was its director until 1947, being succeeded by Adriano Buzzati Traverso. At Jucci's instigation, a center for the genetic study of alpine animal and plant populations was established on Mount Terminillo, becoming fully operational in 1954.

A member of several Italian and foreign academies, Jucci died in Rome on 22 October 1962. He related the different colors of the cocoon, linked to the color of the hemolymph, to the metabolism in the different breeds of silkworms.

By studying the transmission of the colors in different races, he understood that the emergence of a character derives from cellular biochemical processes, as the cocoon’s color that is related to the permeability to certain substances present in food.

Through On the pigments of blood, cocoons and eggs in silkworms (in Rend. Dell'Acc. Dei Lincei, class of physical sciences, s. 6, XI , pp. 86–90) and a comparative examination between two races, he found that even the early or late moment of the migration of the pigment from the blood to the cocoon is following Mendel’s Laws. With the work On the color of the cocoon and migration, he provided the answer to the question about the dominance or recessiveness of genotypic characteristics in the first generation.

In his book Maternal inheritance studied in the characteristics of silkworms (in Rivista di zootechnical, II 1925, 5, pp. 15–23), after many experiments, he criticized the existence of an inheritance linked to the cytoplasm debated by among the geneticists.

With his later studies in Naples, he highlighted the high degree of natural immunity present in the moth of the hives against acid-resistant bacteria, because of digestive enzymes of the wax and the presence in the intestine of caterpillars. After that, he tried to provoke the same resistance in other animals with a waxy substances diet. In the following years, he expanded his participation in international scientific events and through the research centers he founded he could deepen his investigation.