Horizontal gene transfer

==Horizontal gene transfer==
Transfer of genetic material between organisms by a mean different than by reproduction. By gene transfer, organisms can acquire DNA from an individual without being his descendants. The exchanged DNA is sometimes referred to as promiscuous DNA. 
Horizontal gene transfer in prokaryotes
Horizontal gene transfer causes bacterial resistance to antibiotics. There are tree methods of transfer of DNA between prokaryotic cells: transformation, conjugation and transduction. 
===Transformation===
Transformation is a process of uptaking "naked DNA" from the environment. A direct contact between the donor and the recipient is not usually necessary, which distinguishes transformation from other methods of gene transfer. Transformation can be either naturally occurring or artificial.
===Conjugation===
Is a type of horizontal gene transfer (of transfer of DNA) between two connected cells It is reffered to as the prokaryotic “mating”, but it doesn't require a formation of a zygote. Bacteria use for cennection pili and DNA is transferred in plasmids (F plasmids) or transposones and it requires a special origin of transfer-oriT. 
TransductionIs a form of genetic material transfer from one bacterial cell to another via a viral particle (a bacteriophage). Bacteriophage build in their DNA into the host organism, during replication, phages pick up fragments of the host DNA and transmit them into the recipient strand.
==Horizontal gene tranfer in Eukaryotes==
Horizontal gene transfer occurs even in Eukaryotes. As an example could serve the exchange between the nuclear DNA and the semi-autonomous organelles, such as mitochondria and chloroplasts.