Antisense strand of DNA

Stephen R. Lasky Stephen_Lasky at
Fri Dec 22 08:52:40 EST 1995

Mick and Ken: 

I am going to do it again.  That is "correct" you on this point.  You are
both wrong.  I sincerely hope you are don't  teach molecular genetics to
students before you get this right.  The sense strand is the strand that
is transcribed into mRNA and therefore is the anti-parellel complement of
the mRNA.  I realize that this is contra-intuitive given the convention of
placing the strand that is equivelant to the mRNA on the top of published
sequences and also given the meaning of anti-sense RNA, but you both have
gotten it backward.

Mick, your really should check references from  "the good old days" before
you cite them.  If you go back and look any number of early molecular
genetics textbooks you will find definitions similar to:

1: "Since ... the resultant mRNA is translated in a 5' to 3' direction it
follows that the beginning of the gene will lie to the 3' end of the SENSE
STRAND (caps my own) and the conclusion of the gene will lie at the 5'
end.  The sole function of the anti-sense strand is to generate a
complementary sense strand for use by the next generation of virus or
cell.  The sense strand will give rise to an antisense strand during
replication".  U. Goodenough, Genetics, circa 1980.

2:  "The COPIED strand of DNA which contains the actual code for a protein
is known as the SENSE STRAND.  Its partner is known as the antisense
strand."  R.A. Woods. Molecular Genetics (i think), circa 1978.

Please note that in the definition of the sense strand is the strand that
is copied by the RNA polymerase.  It is read in the 3' to 5' direction,
polymerizing ribonucleoside triphospates into a strand growing the the 5'
to 3' direction that is anti-parellel and complementary to the template
(sense) strand.

I would give you more quotes, but I have donated all of my old genetics
books to charities that take them to Central America but another book that
I suggest for all students of molecular genetics, that is "Molecular
Genetics" by Gunter Stent.  While this book is dated (as is Goodenough's
statement about the anti-sense strand) it is extremely well writen and
gives you an historical perspective on the early development of molecular

If you can find published works that substantiate your definition of the
sense strand as being the same as the mRNA, I would appreciate the

Ken, since you are in the UC system, I suggest you make an intercampus
call to a couple of classical geneticists so that you can get this right. 
You might want to call D.E. Morse (one of the early workers on Trp
attenuation with C. Yanofsky and one of the first persons to show the
polarity effect of nonsesnse mutations), E. Englesberg and N. Lee (who
defined postive regulation of gene expression in the Ara operon), or even
R. Sinsheimer who used to be at UCSC.  All of these people are now at
UCSB, and except for Sinsheimer, are the scientists who I learned genetics

As I said, given our current conventions, the definition of a sense strand
is contra-intuitive, but as scientists, when there is a question about a
definition, it would serve you well to go back to the literature in order
to make sure you have it right.

> Mick,
> I responded on Dec. 11th with pretty much the same answer you gave and 
> was "corrected" (sorry, I didn't save the message since it was the only 
> one I received and I'm pretty sure that my/our response is the correct one):
> I wrote:
> <<More simply put, the sense strand of a "DNA sequence which is
> <<transcribed into RNA" is that strand whose sequence is identical to 
> <<that of the RNA (with the replacement of T's to U's), and so the antisense
> <<strand is that strand whose sequence is complementary to that sequence.
> <<The antisense strand is the strand which is read during transcription.
> <<
> On 14 Dec 1995, Mick Jones wrote:
> >This is always a problem for new students to molecular biology.
> >DNA is double stranded, and the DNA strand that is identical to the 
> >transcribed RNA (except for Us for Ts) is called the SENSE strand.  The 
> >complementary strand, which acts as the template for transcribing the
> >RNA is called the ANTISENSE strand.
> Thanks for coming to my rescue.
> Ken Howe
> "the onions expressed here are my own"

Stephen R. Lasky Ph.D.   Brown U/Roger Williams Medical Center,  Providence, RI.   
Phone: 401-456-5672     Fax: 401-456-6569     e:mail: Stephen_Lasky at
America may be unique in being a country which has leapt from barbarism to decadence without touching civilization.  John O'Hara.

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