In molecular biology, the stretch of DNA
base pairs that lie in the 5´ direction from the site of initiation of
transcription. Usually the first transcribed base is designated +1 and the
upstream nucleotides are marked with minus signs, e.g., -1, -10. Also, to
the 5´ side of a particular gene or sequence of nucleotides.
The region extending in the 5' direction
from a gene
Hypermedia Glossary Of Genetic Terms.