4.1.3 Survey of the terminators used
In the approved transgenic crops the terminator that is used most
frequently to terminate transgene transcription is nos 3', isolated
form the nopaline synthase gene from Agrobacterium tumefaciens.
It has been used in at least 16 of the 28 products. No data were
available on the terminators of three transgenes used in two different
crops (Papaya [ID 26] and rapeseed [ID 60]).
Figure 6.: Number of occurrences of the most frequently
used terminators introduced into the currently approved genetically
engineered agricultural crops (in total 28 distinct products were
approved; see text). In some cases (indicated by asterisks) distinct
variants of the respective terminator were used
(see Terminators in approved transgenic agricultural crops).
In at least seven products the terminator
of the cauliflower mosaic virus (T-35S) or derivatives thereof
was used, while the plant-derived terminator E9 3' (from pea)
was employed in five crops and ocs 3', Tr7 3' and tml 3' (all
from Agrobacterium tumefaciens) in at least four and three
products, respectively (Approved genetically modified crops in the United States,
Approved genetically modified crops in the European Community and
Terminators in approved transgenic agricultural crops,
Figure 6). Another five terminators were used in a single crop