May 10th, 2018
(written by lawrence krubner, however indented passages are often quotes). You can contact lawrence at: email@example.com
My friend Lark points me to this, and I am surprised to realize that the theory of epigenetics was around for a long time before it gained acceptance:
McClintock and the Theory of Epigenetics
Beyond her discovery of TEs and her revolutionary cytogenetic research techniques, Barbara McClintock was also the first scientist to correctly speculate on the basic concept of epigenetics-or heritable changes in gene expression that are not caused by changes to DNA sequences. Mainly, she recognized that genes can be expressed and silenced during mitosis in genetically identical cells. McClintock proposed this theory before the molecular structure of DNA and more than 40 years before the concept of epigenetics was formally studied, thereby further cementing her reputation as an innovator in her field.
Barbara McClintock’s discovery of transposable elements in Zea mays changed the way scientists think about genetic patterns of inheritance. Although not widely accepted at the time of its discovery, McClintock’s observation of the behavior of kernel color alleles was revolutionary in its proposition that genomic replication does not always follow a consistent pattern. Indeed, as a result of both autonomous and activator-controlled transposition at different stages of seed development, the genes of maize kernels are capable of producing a variety of coloration patterns. Over time, McClintock’s work with TEs became widely accepted, and McClintock eventually earned a Nobel Prize for her discoveries in this area. Today, McClintock is also recognized for her groundbreaking cytogenetic techniques, as well as her early speculations on the concept of epigenetics. Thanks to these and other valuable contributions to the field, Barbara McClintock is rightly viewed as one of the pioneering figures in modern genetics.