Dolly Sheep

Name: Sharon Chávez Izquierdo Course: Sixth Quibio “A”
SHEEP DOLLY
Dolly was a female sheep, and the first mammal to be cloned from anadult somatic cell, using the process of nuclear transfer. She was cloned by Ian Wilmut, Keith Campbell and colleagues at the Roslin Institute and the biotechnology company PPL Therapeutics inScotland. She was born on 5 July 1996 and she lived until the age of six, at which point she died from a progressive lung disease. Dolly was the first clone produced from a cell taken from an adult mammal.To clone Dolly, researchers took a cell from the udder of a six year old Finn Dorset sheep, and kept in a nutritional solution. They then deprived the cell of the nutrients which made the cell's DNAgo into a 'sleeping' state. She was created using the technique of somatic cell nuclear transfer, where the cell nucleus from an adult cell is transferred into an unfertilized oocyte (developing eggcell) that has had its nucleus removed. The hybrid cell is then stimulated to divide by an electric shock, and when it develops into a blastocyst it is implanted in a surrogate mother. The nucleus of asheep egg cell from another ewe was then removed, and inserted the sleeping cell into the now nucleus-free egg cell. The two combined cells with were then given an electric shock, and to thescientist surprise, the combined cells acted like a fertilized egg cell and starting to divide and grow, thus starting the development of Dolly. The egg was then implanted into a third ewe and a few monthslater, Dolly was born. She was genetically an exact copy of the ewe from which the udder cell was taken.
There are two possible reasons for why Dolly died far too young:
Telomere shortening:Telomeres are the ends of a chromosome. As each cell replicates, the telomeres grow progressively shorter. Scientists believe cells stop replicating when the telomeres reach some critical length. Dolly's...