2.  We have mentioned previously that it is possible to insert DNA from one organism to another ◦ These are known as transgenic organisms  These have many uses ◦ Production of human proteins (such as insulin) in bacteria ◦ Modified crops to increase yield  But the more notable, and controversial, transgenic organisms would be clones

3.  Scientists have developed methods to make genetic copies (clones) of entire organisms  The problem came from the fact that cells will differentiate during the embryonic stage, and could not revert back  The answer came when it was discovered that cells in G 0 could be forced into a totipotent stage  This was first successfully performed in 1996 with the creation of Dolly

4.  Dolly was created by removing a mammary cell from an adult sheep  The cell was forced into G 0, and its nucleus removed  An egg cell from another sheep was removed, and its nucleus was removed  The nucleus from Dolly’s donor was inserted, and the egg was implanted into a womb  The lamb that was born (Dolly) was the genetic copy of the donor

6.  Dolly was euthanized when she was 6 ◦ Most sheep live 10-12 years  It was speculated that her genetic age was older than her birth age  Her telomeres were artificially short, since she was cloned from an older sheep  This raised questions about the viability of cloned organisms

7.  Blood and tissue samples are often left at particularly violent crime scenes  Scientists used to use blood type as a method of indentifying a defendant ◦ However, this only proves if a person is innocent  DNA fingerprinting (now called profiling) can indentify the guilty individual with a much higher certainty  A few different methods have been used

8.  Many of the technologies we have discussed are used to directly assist humans  In particular, DNA fingerprinting has become quite useful

9.  Restriction fragment length polymorphism  Restriction enzymes are added to suspect’s DNA, and samples of DNA at crime scene  The length of introns is variable in a population  When a gel is ran, the two samples are compared

11.  More recently, variation in the lengths of satellite DNA have been used  These are repeats of the same 1-10 nucleotides, and are highly variable in humans

12.  Restriction enzymes are still used

13.  Started in 1990, projected completion by 2005  Essentially completed in 2000, officially announced in 2003  First found sequence of small sequences far apart ◦ Used these as makers  Cut the genome up into many smaller segments, and sequenced these separately  Computer analyzed to find areas of overlap

14.  Aligned these, with markers, to get complete version  Called this shotgun sequencing  Next up was to look for genes  Scan for promoting regions  Then, have to differentiate between intron regions and exon regions  Indentifying the genes is the first step in gene therapy  Is the proper sequence is known, a strand can be engineered into a virus, and inserted into a patient