They learned that Lgl had just one binding partner soon to be known as Mahjong.
"In addition to identifying Mahjong and its relationship with Lgl," said Deng, "we confirmed that both genes function in the same pathway in both fruit flies and mammals to regulate cellular competitiveness."
To determine if a mutation would induce cell competition in fruit flies, the Florida State biologists modified fly larvae by deleting the Mahjong gene from subsets of the wing-tissue cells.
Then, using a fluorescent probe that can identify cells undergoing apoptosis (a form of programmed suicide), they saw that cell death was occurring in the Mahjong mutant cells that were adjacent to normal cells, but not in those surrounded by fellow Mahjong mutants.
"In competition with their normal neighbors," said Tamori, "cells without Mahjong were the losers."
After Tamori and Deng confirmed the role of Mahjong in fruit fly cell competition, their collaborators at University College London sought to induce competition in mammalian cells.
To replicate as closely as possible the occurrence of mutations caused by environmental factors, Fujita and his team engineered kidney cells whose copies of the Mahjong gene could be shut down by the antibiotic tetracycline. Before adding tetracycline, they mixed the engineered cells with normal ones and allowed them to grow and form tissue.
|Contact: Yoichiro Tamori|
Florida State University