March 12, 1999

"The Sky's the Limit!"
Janet D. Rowley, M.D.
Blum-Riese Distinguished Service
Professor of Medicine and of Molecular
Genetics and Cell Biology
Department of Human Genetics
The University of Chicago

Dr. Rowley will review the progress made in the microscopic analysis of chromosomes from standard Giemsa Stains in the 1950's and 1960's to banding techniques in the 1970's and now the latest techniques that label each chromosome with a unique combination of fluorochromes.

Bio Sketch

Dr. Janet Rowley received her B.S., Ph.D., and M.D. all in medicine from the University of Chicago. Her professional experiences began as a Research Assistant at the University of Chicago in 1949 where she is actively doing research.

Selected honors include: Member of the National Academy of Sciences; Fellow, American Association for the Advancement of Science; Albert Lasker Clinical Award (co-recipient); National Medal of Science.

SMSI Meeting Report of March 12, 1999

The meeting was called to order at 7PM by Bill Mikuska who returned to duty after missing the previous month's session due to illness. The featured speaker, Dr.. Janet Rowley, promptly declared herself to be a rather non-technical person with respect to microscopes and then proceeded to dazzle the attentive audience with a colorful series of fluorescence microscopy images. Dr. Rowley is a pioneer in leukemia research at the University of Chicago and has long probed the issues surrounding the genetic changes which occur when cells metamorphose from ordinary healthy cells to cancer cells. Thirty years ago it had been debated as to whether or not changes in chromosomes played a role in cancer genesis or were 'merely' a secondary consequence of the disease's onset. In the seventies a technique of banding the chromosomes by staining with Giemsa and later with various dyes made it possible to label chromosomes. It turned out that in leukemia all the chromosome parts remained; some of them translocated from, say, the end of the long arm (q) of one chromosome to the short arm (p) of a different chromosome.

Fluorescence in situ hybridization (F.I.S.H.) made it possible to mind our chromosomal p's and q's and eventually lead to very precise mapping of the contents of helix strands. Hybridized probe detection and precise labeling techniques yielded insight into the split in chromosome 16, which has at least 100 kilobases (100,000 pairs of bases), and subsequent translocation to chromosome 11, leading to a description of an 'event' associated with leukemia. A specific therapy involving retanoic acid developed directly from this work.

A number of other genetic mapping and tracking techniques were discussed, including SKY a spectral imaging technique which utilizes unique fluorescent color signatures for each chromosome. This combination of Fourier spectroscopy and CCD imaging, developed in Israel, incorporates the use of an interferometer.

Although all of the color slides were fascinating, especially so were those demonstrating the beautiful colors given to the 23 chromosomes by M. F. Smith. Questions followed the close of the presentation and lead to a short discussion regarding problems encountered in the staining process.

The meeting was adjourned shortly after 8PM.

Report submitted by John Macdonald, Recording Secretary.