Tue Nov 27, 2012, 01:53 PM
HuckleB (31,611 posts)
What does GMO really mean?
"For years, journalists, television producers and newspaper reporters that write about genetically engineered crops, have used the term “GMO” (genetically modified organism) to describe these new crop varieties. The marketing industry has taken to writing “GMO-free” on their products, as a way to increase sales to consumers fearful of the genetic engineering process.
Breeders have a 8000 year history of genetic modification (also called genetic improvement or conventional breeding)- that is, they have modified the genome of crop species in a number of ways. Such conventional breeding methods include hybridization (transfer of pollen from one plant variety to another to generate new seed with genes from both parents), mutagenesis (in which chemicals or irradiation are used to induce random mutations in DNA) and embryo rescue (where plant or animal embryos produced from inter-species gene transfer are placed in a tissue culture environment to complete development). Today, everything we eat has been genetically modified in some way.
Genetic engineering, in contrast, uses a direct method to introduce new genes into a crop. Because the transfer is not limited by the relatedness of the parental varieties, any gene, even a gene from another species can be introduced into a crop plant. A committee established by the National Academy of Sciences was asked to look carefully at the GE process. Their report concluded that the process of genetic engineering is not inherently hazardous. However, as with every other technology used for genetic modification, GE carries the potential for introducing unintended compositional changes. It depends on what gene is introduced or modified. For example, a new celery variety developed through conventional breeding that carried improved resistance to pests caused some farm workers to develop a rash on their hands when harvesting. In contrast, after 1 billion acres of GE crops grown over 10 years, there has not been a single instance of harm to human health or the environment.
The method that we used to develop flood tolerant rice is called precision breeding, which is a sort of hybrid between genetic engineering and conventional genetic modification. Precision breeding (also called marker assisted selection) uses DNA technology to detect the inheritance of a desired gene to a seedling resulting from a genetic cross between two parent varieties. The result is the precise introduction of one to several novel genes from closely related species. For example, our flood tolerant rice was developed from a cross of a low-yielding rice variety that carried a rare gene for tolerance with modern, locally adapted modern varieties. The resulting seedlings were screened using precision breeding to develop new varieties with the taste and yield favored by consumers with the flood tolerant trait. The rice is now being grown by farmers in Bangladesh and India, where 4 million tons of rice are lost each year to flooding, enough to feed 30 million people.
A good piece as a starter in an attempt to bring science and perspective to the discussion of GE/GMO.
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Replies to this discussion thread
What does GMO really mean? (Original post)
Response to HuckleB (Original post)
Tue Nov 27, 2012, 09:26 PM
svpadgham (594 posts)
1. Thanks for posting this.
As a former student of biotechnology, I have become aware of the processes that go into genetic modification. It struck me as ridiculous when people would be up in arms about GMO's. It's much the same with producing rBGH. I believe the real problem is how certain corporations go about their business and treat small farmers or home gardeners.
Response to HuckleB (Original post)
Wed Nov 28, 2012, 07:52 AM
xchrom (108,903 posts)
2. while i'm doubtful about the necessity of - or even the safety - of some engineering --
this is a good read.