Talking Glossary of Genetic Terms
Metaphase is a stage during the process of cell division (mitosis or meiosis). Usually, individual chromosomes cannot be observed in the cell nucleus. However, during metaphase of mitosis or meiosis the chromosomes condense and become distinguishable as they align in the center of the dividing cell. Metaphase chromosomes are used during the karyotyping procedure that is used to look for chromosomal abnormalities.
Metaphase is a stage in the cell cycle where all the genetic material is condensing into chromosomes. These chromosomes then become visible. During this stage, the nucleus disappears and the chromosomes appear in the cytoplasm of the cell. During this stage in human cells, the chromosomes then become visible under the microscope. As metaphase continues, the cells partition into the two daughter cells. Cells in metaphase are used in medical research to measure whether all of the chromosomes are present and whether or not they are all intact. This process of looking at chromosomes under the microscope is called karyotyping.
Name: Lawrence C. Brody, Ph.D.
Occupation: Chief & Senior Investigator, Genome Technology Branch; Head, Molecular Pathogenesis Section
Biography: Dr. Brody investigates the genetics of breast cancer and neural tube defects. As chief of the NHGRI Genome Technology Branch's Molecular Pathogenesis section, he is interested in studying genetic mutations that lead to perturbations in normal metabolic pathways and cause disorders such as cancer and birth defects. His laboratory investigates mutations in two breast cancer-linked genes, breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2). Dr. Brody's laboratory was among the first to report that women carrying BRCA1 or BRCA2 mutations have a higher risk of developing both breast and ovarian cancer than women without such mutations.