The Genetic Basis of Identity
DNA technology has many practical uses. Because every individual has a unique DNA sequence, DNA samples can be used for identification. The legal system is now using DNA evidence to determine guilt or innocence. The application of DNA technology began in Britain in the mid-1980s and appeared in America shortly afterward. Today many societies have […]
Germ Warfare Among the Lower Eukaryotes
Paramecium is a well-known ciliated protozoan. Many strains of Paramecium carry symbiotic bacteria ( Caedibacter ), known as kappa particles , that grow and divide inside the larger, eukaryotic, Paramecium cell. Those strains of Paramecium with kappa particles are known as killers. Killing occurs when kappa particles are released by a killer and eaten by […]
Biological warefares
INTRODUCTION Biological warfare involves not only choosing a disease agent and perhaps modifying it genetically, but also manufacturing and storage, weaponization, and delivery. Accusations of using biological warfare or developing biowarfare agents are often made as propaganda ploys in the absence of any real evidence. Suspicious outbreaks of disease have frequently led to accusations of […]
Trangenic Insects
Several insects can now be genetically modified. The fruit fly Drosophila has been investigated at the molecular level for a long time and, not surprisingly, methods exist for introducing novel genetic material into these flies. P elements are transposons found in Drosophila and other insects, where they cause hybrid dysgenesis . In flies carrying […]
Transgenic Mosquitoes
The three diseases that kill most people are acquired immunodeficiency syndrome (AIDS), tuberculosis, and malaria. Each year, malaria infects some 300 to 500 million people and kills around 2 million, mostly African children. The Plasmodium parasite is transmitted by mosquitoes—as are several other major diseases including yellow fever, dengue fever, and filarial nematodes. At the […]
Recombinant Protien Production Using Transgenic Livestock
The somatotropin gene from cows has been cloned and expressed in bacteria thus allowing the production of large amounts of the hormone, which is known as rBST (recombinant bovine somatotropin) . The rBST is used in the dairy industry to increase milk production. Unlike in mice, boosting an adult cow’s somatotropin levels by injection of […]
Constructing a Library of Genes
Gene libraries are used to find new genes, to sequence entire genomes, and to compare genes from different organisms. Gene libraries are made when the entire DNA from one particular organism is digested into fragments using restriction enzymes, and then each of the fragments is cloned into a vector and transformed into an appropriate host. […]
Knockout Mice for Medical Research
Transgenic animals, mostly mice, are of great value in the genetic analysis of inherited diseases and cancer. Here we are interested not so much in adding a cloned transgene as in discovering the function of genes already present. The general approach is to inactivate, or “knock out,” the gene of interest and then ask what […]
Transgenic Animals
NEW AND IMPROVED ANIMALS For thousands of years people have improved crop plants and domestic animals by selective breeding, mostly at a trial-and-error level. Woollier sheep and smarter sheep dogs have both been improved through many generations of selective breeding. Obviously, the more we know about genetics, the faster and more effectively we can improve […]
BT Toxin and Butterflies
Another issue with transgenic plants is the effect they may have on nontarget organisms , that is, any plants or animals inadvertently exposed to the transgenic crop or insecticide. An article in the journal Nature suggested that Monarch butterflies were killed by eating pollen from corn carrying the Bt gene. The study alarmed the science […]