Estimates of the number of human genes have fallen and narrowed in range over the years as research has shed more light on how genes are arrayed along DNA. Credit: M. Pertea and S. Salzberg/Genome Biology 2010, Adapted by E. Feliciano
High-contrast direct DNA image. Transmission electron micrograph (TEM) of the first high-contrast direct image of a bundle (fibre) of strands of DNA (deoxyribonucleic acid). This bundle is six DNA strands wrapped around a seventh. The inset at lower right shows the helical structure, with the red arrows pointing to the edges of the helix. The width of a DNA strand is 20 angstroms (2 nanometres), and the scale bar (bottom left) is 20 nanometres long. This image was obtained by a team led by Enzo di Fabrizio from the Department of Nanostructure, at the Italian Institute of Technology (IIT) in Genoa. The results were published in November 2012 in the journal Nanoletters, and in Nature in January 2013.
This two-hour special, hosted by ABC "Nightline" correspondent Robert Krulwich, chronicles the fiercely competitive race to capture one of the biggest scientific prizes ever: the complete letter-by-letter sequence of genetic information that defines human life—the human genome. NOVA tells the story of the genome triumph and its profound implications for medicine and human health.
Epigenetics -- hidden influences upon the genes -- could affect every aspect of our lives. The lives of your grandparents -- the air they breathed, the food they ate, even the things they saw -- can directly affect you, decades later, despite your never experiencing these things yourself. And that what you do in your lifetime could in turn affect your grandchildren.
James
Watson and Francis Crick's classic paper that first describes the
double helical structure of DNA. With some understatement they note that
the structure “suggests a possible copying mechanism for the genetic
material”.