How Can Transgenic Animals Be Used To Create Recombinant DNA Cloning?

Recombinant DNA technology involves combining different sequences of DNA in order to create a new sequence. This technology can be used in many different areas of research, but our project focuses on the use of recombinant DNA technology to create transgenic animals. Transgenic animals are created by introducing genes from one species into the genome of another animal. In order to create transgenic animals, DNA cloning must first be understood. This process usually follows two basic elements. To begin, a segment of DNA is placed in culture and grown in vitro. Restriction enzymes are then introduced in order to slice the DNA into a specific fragment at specific sites, called restriction sites. An example of a common restriction enzyme is Eco-RI,

Cloning vectors are molecules that possess an origin of replication, allowing the fragmented DNA to replicate with the vector as it copies itself. Plasmids, which are circular DNA molecules, are common choices for gene cloning. In order to insert the specific DNA fragment into the plasmid, the plasmid must first be cut by the same restriction enzymes. Eco-RI would once again be utilized to cleave and open up the circular plasmid molecule into a linear form, also with sticky ends. Once the fragment is placed near the plasmid, the ends of the plasmid and fragment can be annealed and sealed together by DNA ligase to create a recombinant DNA

Plasmids containing new DNA can still replicate, only now the specific DNA fragment will replicate as the plasmid does, creating billions of copies of the donor fragment. At this point, the cells undergo the usual steps for gene expression. These include DNA being transcribed into mRNA, removal of introns through splicing, and translation of mRNA. The ability to use recombinant DNA technology to produce precise clones of DNA has allowed scientists to discover the process by which one organism’s DNA can be introduced into and combined with another organism’s genome. A transgene is the specific gene added into another genome. A transgenic organism, or genetically modified organism (GMO), is the organism with the new genome containing the transgene. There are three methods by which transgenic animals can be created: DNA microinjection, retrovirus-mediated gene transfer, and embryonic stem cell-mediated gene transfer.

For DNA microinjection, the desired gene must first be created in vitro through the cloning methods described earlier. This DNA is then inserted into the nucleus of an egg ell that has been isolated from an animal. The egg cell is then implanted into a surrogate organism’s oviduct where it can