Cloning

            
             The history behind the concept of cloning dates all the way back to 1902 when Walter Sutton proved chromosomes contained genetic information. This is what is widely accepted as the "beginning- of cloning, as we know it today. Also in 1902, Hans Spemann divided a salamander embryo into halves and showed early embryo cells contained all the genetic information necessary to create new organisms. A few years later, in 1907, American scientist Thomas Hunt Morgan began work on the first "chromosome map."" This map was created to show the location of genes. Morgan used fruit flies in his experiments because of their "simple genetic structure and rapid breeding."" (http://library.thinkquest.org/C0122429/history/history.htm). In 1928, Hans Spemann conducted the first nuclear transfer experiment. He used "salamander embryos, where he transferred the nucleus of a salamander embryonic cell into a cell with no nucleus. Using a strand of hair, he tightened a loop around a newly fertilized egg, until he separated the nucleus and some of the cytoplasm. The side with the nucleus divided until it has sixteen cells. Spemann then loosened the loop and let the nucleus from one of the embryonic cells to move over into the cytoplasm of the other side. He tightened the loop even more and separated the cytoplasm with the new nucleus from the other embryo. A normal salamander embryo grew from that cell. This experiment proved that the nucleus of an early embryo cell can lead to the growth of a complete organism."" (http://library.thinkquest.org/C0122429/history/1928.htm). Ten years later in 1938, Spemann had another vision. He envisioned Cloning with differentiated cells by nuclear transfer. He wrote a book in which he included his experiment of ten years prior; also he brought about the idea of cloning organisms by removing the nucleus of a separate cell and inserting it into an fertilized egg in which the nucleus had been removed.