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Every science requires a special language because every science has its own ideas.
~Étienne Bonnot de Condillac (1715-1780)
recombinant bovine growth hormone
a synthesized version of a protein hormone naturally produced in the pituitary glands of cattle. rBGH was developed to increase milk production in dairy cattle. Since it is a protein (rather than steroidal) hormone, it is biologically inactive when consumed by humans. However, its administration to cows negatively impacted their health and welfare. In the US, the vast majority of milk products are therefore now rBGH-free.
|recombinant DNA technology|
|red, green, and white GE||
genetic engineering applications can be broken down into three areas: medical (red), agricultural (green), and industrial (white). Red and white applications have resounding public approval, while green applications remain controversial.
the simplification of complex genotypes to form homozygous parental lines, which are then used to make classical breeding vastly more efficient. First, crosses are made under conditions that prohibit homologous recombination. Then male or female spores from the resulting plants (which contain various mixtures of non-recombinant parental chromosomes) are cultured in vitro to generate homozygous doubled haploid plants.
gene to phenotype. In reverse genetics, the gene sequence is known, but the phenotype is not. Genes are altered in order to illuminate their affect on phenotype. Techniques used in reverse genetics approaches include directed deletions and point mutations, gene silencing, and gene interference. See also forward genetics.
genetically engineered papaya that saved Hawaii's papaya crop from decimation in the 1990s. Created by inserting the gene for a ringspot virus coat protein into papaya, rendering the plant resistant. The GE papaya yields 20 times more than the conventional variety and was distributed for free to growers. Other than genetic engineering, no viable approach to combating papaya ringspot virus existed then or now.
some RNA molecules are used to synthesize proteins directly (e.g. messenger RNA, ribosomal RNA, and transfer RNA). Others modify other RNAs (e.g. small nuclear RNAs that facilitate the removal of exons from mRNAs during translation, or ribonucleases that form functional tRNAs). Still others act as translational regulators (e.g. antisense RNA that binds to complimentary mRNAs, physically obstructing translation; small interfering RNA that binds to mRNAs, targeting them for enzymatic degradation; and microRNA that binds to mRNAs, repressing translation and silencing genes. Biotechnologists can use the RNA translational regulators already present in plants or algae in order to enhance the production of biofuels, pharmaceuticals, etc (see epigenetics).
the brand name of a systemic, broad-spectrum herbicide produced by the US company Monsanto that contains the active ingredient glyphosate, as well as a surfactant that increases the herbicide’s penetration. Monsanto’s patent on glyphosate expired in 2000, allowing other companies to produce it.
soybean, canola, cotton, corn, or sugar beet plants genetically engineered to be tolerant to the broad-spectrum herbicide glyphosate (Roundup, etc). Roundup Ready crops allow farmers to use glyphosate against most weeds. RR crops sometimes yield better (e.g. sugar beet), and support usage of no-till farming techniques. When RR crops are not used as part of an integrative pest management strategy, glyphosate-resistant weeds arise. The US-based company Monsanto markets RR seeds — their US patent on RR soybeans will expire in 2014.
Roundup Ready sugar beets
GMO sugar beets
sugar beets genetically engineered to withstand the weed killer, glyphosate. Because sugar beets grow so slowly and weeds grow so quickly, weed control is a beet farmer’s number one challenge. When they grow RR beets instead of conventional beets, farmers are able to cut the number of cultivations and herbicide applications pretty much in half. Their yields go up, their costs go down, and their crops have a markedly reduced environmental impact (because less fuel and fewer chemicals are used). There is very little risk of gene flow in sugar beet root production because the crop is harvested well before it flowers. Seed production does have a gene flow risk because the beets are allowed to flower and disperse pollen. This risk can be mediated by imposing isolation distances between fields and by using non-RR male plants as pollinators for male-sterile, RR female plants.