It is not true. There’s a lot of misinformation about GM crops on the Internet including the idea that there are animal genes in tomatoes. While there have been laboratory experiments where a gene was introduced that was based on a gene from an animal (the one folks may be most familiar with is a flounder gene in tomatoes to see if it would make them more cold tolerant), none of our companies have commercial GM crops on the market that are genetically modified to contain animal genes. With regard to GM tomato, there are not currently any commercial products on the market.
It should be noted, though, that plant scientists who study the genomes of plants have estimated that about 60% of the genes present in plants have very similar copies in animals. This is not surprising, since all organisms use the same genetic toolbox. DNA from any source is made up of the same four basic nucleotide building blocks: adenine (A), cytosine (C), thymine (T) and guanine (G). So DNA that comes from a plant or a microbe has the same four nucleotides as the DNA in animals. When any DNA is ingested it is broken down into these nucleotides which are further broken down and absorbed or excreted.
You may want to read more detailed articles that provide more in-depth information related to your question:
- The Skeptical Vegan: http://skepticalvegan.com/2012/05/02/animal-genes-rothamstead-wheat-trial/
- Karl Haro von Mogel: http://www.biofortified.org/2009/11/youre-eating-viral-dna/
- Reason.com: http://reason.com/archives/2002/11/27/veggie-tales
- Beyond the Rows (Monsanto blog): http://monsantoblog.com/2009/04/13/gmo-vegetables-animal-dna/