Barbara McClintock The scientist who discovered jumping genes

Kevin Jones

Early years Barbara McClintock was born in June, 6 1902, and lived in Hartford, Connecticut, with a very active lifestyle. Her father was an army doctor and her mother was a piano teacher. She enjoyed playing volleyball, skating, and swimming.

College Her passion for

information led her to Enroll in Cornell University(the college of agriculture). McClintlock thrived academically, So much so that in her second year of graduate school, she was a paid assistant working in cytology.

career When she graduated

with her Ph.D. in 1927, she stayed at her college as an instructor, in order to map corn chromosomes in linkage groups.

Discovery For the 20th century,

many people believed that genes were formed in a pattern, which formed a chromosome, linked together like a necklace. Barbara challenged that concept. she discovered that genes could in fact, be mobile. Her discovery was found in corn. A chromosome-breaking locus that could change its position within a chromosome, a.k.a transposons.

Why doesn't it kill us? Transposons change our genetic

structure, specifically in our chromosomes. And it leaves a copy of itself where it was before. Can’t that kill us? Transposase binds to either end of the transposons , then, brings the transposons together. The transposons interfere with each other. The transposition process is then halted.

Rejection The idea that genes could move seemed very “confusing” to the scientific community. Being so used to the simple idea that genes could not move, they did not accept her idea of jumping genes. She needed a reason why genes could still remain stationary, and yet be able to “jump.”

Explanation In the 1950s McClintlock discovered a

key element in her discovery, a suppressor-mutator (spm). Spm’s, mainly are chemicals which turn the jumping genes on and off. The reactions are powered by methylation. Therefore this explains why our genes do not jump as frequently as corn.

Retirement The impact of jumping genes

explains certain types of cancer, mutations, and other radical changes in DNA. Barbra received a Nobel prize for her discovery and her “delayed recognition.” she spent nearly the rest of her life improving upon her discovery. She lived all the way to 1992.

sources http://www.dnaftb.org/

http://www.pnas.org/

http://www.britannica.com/