CHICAGO (AP) — A leading nonprofit group is bringing together researchers at three medical institutions — including two in Chicago — to focus on how gene functions affect premature birth. The March of Dimes will announce the collaboration Tuesday in Chicago. The project combines work from scientists at University of Chicago, Northwestern University Feinberg School of Medicine and Duke University School of Medicine in Durham, North Carolina. The research will include looking at how a woman’s lifelong exposure to discrimination or poverty might alter gene regulation. Premature birth is the leading cause of newborn death in the United States. Carole Ober of the University of Chicago is the primary investigator for the new Prematurity Research Center. March of Dimes is contributing $10 million and the research center will contribute an additional $10 million.