GENETICALLY MODIFIED MICE essays

GENETICALLY MODIFIED MICE essays The science of biology has evolved to the point today that an animals basic nature can be quickly and permanently changed by altering its generic structure. The possibilities that the genetic engineering of animals can bring us is endless; from the Harvard-Dupont mouse prone to developing cancer, to pigs with people-friendly organs that can be used for transplant purposes. But genetic engineering is, as yet, an imperfect science that yields imperfect results and too, endless risks. The use of humans for testing is far too hazardous for first-time products. Therefore, the use of animals, especially mice, as testers is often seen as a way of helping our technological advances. There are two primary techniques that are utilized to modify an animals genome (the unique combination of genes in an individual animal): Transgenesis by pronuclear microinjection and the manipulation of embryonic stem cells. Transgenesis by pronuclear microinjection is the process of permanently introducing a foreign gene into an animal, creating a transgenic animal that is genetically different from any other animal that ever existed. The following steps are taken to create a transgenic animal, the following steps are taken. Female mice are injected with a hormone to induce their ovaries to produce five-six times the number of egg cells that would normally be produced during ovulation, bred with a male mouse, and then killed so that the fertilized egg cells can be surgically removed. After a few hours in culture, the embryos are injected with a gene from another animal (a transgene). In some cases, the transgenes will become permanently inserted into the genetic make-up of the embryo. After a few hours of culturing to allow the cells to grow a bit larger, they are surgically placed into the reproductive tract of a foster mother mouse. In order to receive these manipulated eggs successfully, the foster mother must be induced int ...