<p style="text-align: justify;">Transgenic cotton lines 1445 and 1698 were produced using recombinant DNA techniques to allow for the use of glyphosate, the active ingredient in the non-selective herbicide Roundup&reg;, as a weed control option in cotton crops. The novel plants express a naturally glyphosate tolerant version of the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene isolated from <i>Agrobacterium tumefaciens</i> strain CP4 (CP4 EPSPS). Glyphosate specifically binds to and inactivates EPSPS, which is involved in the synthesis of aromatic amino acids, tyrosine, phenylalanine and tryptophan (shikimate biochemical pathway). EPSPS is present in all plants, bacteria, and fungi but not in animals, which do not synthesize their own aromatic amino acids.</p>

<p style="text-align: justify;">An antibiotic resistance marker gene (<i>neo</i>) encoding the enzyme neomycin phosphotransferase II (NPTII), which inactivates aminoglycoside antibiotics such as kanamycin and neomycin, was also introduced into the genome of these transgenic lines. This gene was derived from a bacterial transposon (Tn5 transposable element from <i>Escherichia coli</i>) and was included as a selectable marker to identify transformed plants during tissue culture regeneration and multiplication. The expression of the <i>neo</i> gene in these plants has no agronomic significance and the safety of the NPTII enzyme as a food additive was evaluated by the United States Food and Drug Administration in 1994 (US FDA, 1994).</p>

<p style="text-align: justify;">Another selectable marker gene, <i>aad</i> (3&quot;(9)-O-aminoglycoside adenylyltransferase (AAD)), was also inserted into the host genome. This gene, which was not expressed in the plants, was used during the development process to select for bacterial colonies that had been transformed with recombinant plasmid DNA.</p>

<p style="text-align: justify;">Unless otherwise indicated, the information presented herein is based on documentation pertaining to cotton line 1445.</p>
