John C Hozier, Professor
Director of Clinical Cytogenetics
John C. Hozier, Ph.D. is Professor of Pathology and Director of the Clinical Cytogenetics Laboratory. The clinical lab employs various forms of chromosome analysis to (detect) chromosome abnormalities that are helpful in the diagnosis of genetic diseases, including birth and developmental defects, and cancer. His long-term research interest is in the structure of mammalian chromosomes and the changes in organization of chromosomes that occur in disease. The research lab uses fluorescence in situ water hybridization (FISH) of DNA probes to chromosomes to study genetic changes in disease. It is possible to see, in the cell nucleus, any gene of interest, and count the number of copies. The number of copies of any gene in a normal cell is two, and deviation from two usually is associated with disease. Rearrangements of chromosomes also are important in cancer, and FISH provides information on such rearrangements as well. The current research focus is on FISH analysis of chromosome alterations in primary tumors of the breast as a possible indicator of long-term survival.
Figure Legend: Fluorescence in situ hybridization of two gene probes to a breast tumor thin section. Nuclei is stained blue. One probe, labeled in red has the normal number of copies per cell, while the other probe (labeled in green) is amplified, having many extra copies per cell. Such changes in gene number per cell have an important impact on disease progression and out-come.
