New York University Skip to Content Skip to Search Skip to Navigation Skip to Sub Navigation

Long-Held Genetic Theory Doesn’t Quite Make the Grade, Biologists Find

September 28, 2012

NYU biologists have discovered new mechanisms that control how proteins are expressed in different regions of embryos, while also shedding additional insight into how physical traits are arranged in body plans. Their findings, which appeared in the journal Cell, call for reconsideration of a decades-old biological theory.

The researchers investigated morphogen theory, which posits that proteins controlling traits are arranged as gradients, with different amounts of proteins activating genes to create specified physical features. This theory has been used to explain why a tiger has stripes, among other phenomena.

The NYU biologists explored this process by studying the fruit fly Drosophila. They focused on one protein, Bicoid (Bcd), which is expressed in a gradient with the highest levels at the end of the embryo that will become the mature fly’s head.

The researchers, headed by Stephen Small, chair of NYU’s Department of Biology, examined a large number of target genes that are directly activated by Bcd. Each target gene is expressed in a region of the embryo with a boundary that corresponds to a specific structure.

By examining DNA sequences associated with these target genes, they discovered binding sites for three other proteins—Runt, Capicua, and Kruppel—which all act as repressors. All three proteins are expressed in gradients with the highest levels in the middle part of the embryo, and thus are positioned in exactly the opposite orientation compared to the Bcd activation gradient.

By changing the spatial distribution of the repressors and by manipulating their binding sites, Small and his colleagues showed that, contrary to morphogen theory, a single gradient of proteins does not have sufficient power to form the same body plan in each member of a species; however, if there are multiple gradients that work against each other, then the system becomes robust enough for normal development.

Type: Article

Press Contact: James Devitt | (212) 998-6808

Long-Held Genetic Theory Doesn’t Quite Make the Grade, Biologists Find

Search News



NYU In the News

NYU Offers Financial Aid to Undocumented Students

The Wall Street Journal reported that NYU will begin offering scholarship aid to undocumented students for the school year beginning next September.

NYU Adopts Lean LaunchPad Program to Teach Entrepreneurship

Startup guru Steve Blank, in a Huffington Post blog, described how NYU adopted the Lean LaunchPad model to teach entrepreneurship to students and faculty at NYU.

Biology Professor Jane Carlton Examines Wastewater for the City’s Microbiome

The New York Times’ Science Times column “Well” profiled Biology Professor Jane Carlton and her research project to sequence microbiome of New York City by examining wastewater samples.

Steinhardt Professors Use a Play as Therapy

The New York Times wrote about a play written by Steinhardt Music Professor Robert Landy about the relationship between Adjunct Professor Cecilia Dintino, a clinical psychologist in the Drama Therapy Program, and a patient, former Broadway actress Jill Powell.

NYU Public Health Experts Urge Strengthening Local Health Systems to Combat Ebola

Dean Cheryl Healton of the Global Institute of Public Health and Public Health Professor Christopher Dickey wrote an op-ed in the Huffington Post saying international health agencies need to strengthen their presence in countries at the local level to prevent future ebola outbreaks.

NYU Footer