The gene, known as S1KLUH, increases cell layers and delays ripening, according to a news release.
It works by promoting extra cell divisions during fruit development immediately after fertilization, leading to larger fruit.
The delay in ripening is likely the result of an extended cell division stage.
In addition to Ohio State University, researchers from France, Spain and the United States participated.
The new-found information could be used to breed new varieties with desired sizes and shapes.