Marine biologist Osamu Shimomura, a co-winner of the 2008 Nobel Prize in chemistry, has died at the age of 90, Nagasaki University announced Sunday.

Shimomura, a graduate of the university and professor emeritus of Boston University, died of natural causes Friday in the city of Nagasaki. He won the Nobel Prize with Martin Chalfie and Roger Y. Tsien of the United States.

They were recognized for the discovery and development of green fluorescent protein (GFP), which has helped researchers establish ways to observe previously invisible processes such as the development of nerve cells in the brain and how cancer cells spread.

Born in Fukuchiyama in Kyoto Prefecture in 1928, Shimomura spent his childhood in Manchuria — now northeastern China, when it was under Japanese occupation — as well as Osaka and other locations before moving to Isahaya near Nagasaki. He experienced the U.S. atomic bombing of the city in 1945 when he was 16.

In 1951, he graduated from Nagasaki Medical Specialized School, predecessor of the Department of Pharmacy at Nagasaki University, and obtained a Ph.D. in organic chemistry at Nagoya University in 1960.

He moved to Princeton University and discovered GFP in 10,000 samples of aequorea victoria jellyfish on the U.S. West Coast.

After serving as associate professor at Nagoya University from 1963, he returned to Princeton and then worked as a senior scientist at the Marine Biological Laboratory in Woods Hole, Massachusetts, from 1982 until his retirement in 2001.