Hobbies And Interests
Bacteria
Most bacteria contain plasmids, which are small fragments of DNA that contain from two to 30 genes. These plasmids can be transferred from parent cell to daughter cell during cell division. They can also be transferred from one individual to another of the same species, to another bacteria of a different species or even into a virus, which is biologically removed from all species of bacteria. Genes coding for antibiotic resistance can be transferred between bacteria by means of plasmids.
Aphids
While genetic material moving directly from one bacteria to another is a common occurrence, multicellular animals generally do not share genes so easily. Such events, called lateral gene transfer, do occur, although only rarely. The pea aphid produces carotenoids, chemicals which make the tiny insect red. This is the only animal in the animal kingdom capable of producing carotenoids, a chemical normally only produced by plants. In 2010, Dr. Nancy Moran of the University of Arizona reported that she had identified the gene within the pea aphid that produces carotenoids and that the gene was picked up by the insect from a fungus during its evolution tens of millions of years ago.
Spidersilk Goats
Scientists are rapidly improving their skills in manipulating the genome. It is now possible to insert desirable genes from one animal into another. A spider's silk is stronger than steel and yet very flexible. The substance could be used to make improved bulletproof vests or artificial tendons -- if it were available in large quantities. Farming spiders for their silk is not practical, so professor Randy Lewis of the University of Wyoming has inserted the spider silk gene into the DNA of goats, creating transgenic animals. These goats, which look and behave like any other farm goats, produce spider silk in their milk, which can then be processed to extract the spider silk proteins.
Retroviruses
When animal cells replicate, the double-stranded DNA molecule is separated into two single strands called RNA, which then have their other half rebuilt to form DNA once more. Retroviruses are viruses that contain RNA molecules. The virus injects its genetic code into a host cell, where the viral RNA gets incorporated into the host DNA with the assistance of enzymes contained within the virus. Whenever the host cell replicates, it will replicate the incorporated viral genes as well. The host cell will be forced to produce the proteins encoded in the viral RNA, which code for the production of more viruses. HIV and certain forms of cancer are caused by retroviruses.