The second DNA string is also important

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The second DNA string is also important

http://www.medicalnewstoday.com/medicalnews.php?newsid=30180

06 Sep 2005

The FANTOM Consortium for Genome Exploration Research Group and

Karolinska Institutet announce the publication of " Antisense

Transcription in the Mammalian Genome " in Science, September 2nd

2005.

It has been known for over half a century that our genetic material

occurs as a double strand of DNA molecules. Only one of these

strands - the so-called sense strand - encodes for proteins, the

building blocks of our cells that in turn make up our bodies. Then

what about the other DNA strand - the antisense strand - can it also

exert functions?

The answer is yes, it can produce so-called antisense genes that are

read in our cells in the opposite direction of the real - sense -

genes. This phenomenon has previously been regarded as rare, but

scientists now show that it is actually the rule rather than the

exception. More importantly, these antisense genes are now shown to

be extensively used to modulate the expression of the conventional -

sense - genes in our cells. Antisense genes are therefore likely to

participate in the control of many, perhaps all, cell and body

function.

These findings are also of interest because synthetic - man made -

antisense molecules have been widely used to inhibit conventional

genes, including applications as anti-viral and anti-cancer drugs,

which are currently on the market or in clinical trials. It can now

be argued that this same principle already has been used by nature on

a massive scale.

Many of the described antisense genes are also unusual because they

do not encode for proteins and therefore do not fit into the

classical definition of a gene.

This concept of non-protein-coding RNA is supported by the data in an

accompanying report entitled " The Transcriptional Landscape of the

Mammalian Genome " by the FANTOM Consortium in the same issue of

Science.

Since mammals, like humans and mice only have slightly more

conventional genes (around 22,000) than a simple worm, the results

clearly indicate that while proteins comprise the essential

components of our cells, the development of multicellular organisms

like mammals is controlled by vast amounts of regulatory noncoding

RNAs that until recently were not suspected to exist or be relevant

to our biology.

Moreover, since most proteins are similar among mammals it also

suggests that many of the differences between species may be embedded

in the differences in the RNA regulatory control systems, which are

evolving much faster than the protein components.

If correct, these findings will radically alter our understanding of

genetics and how information is stored in our genome, and how this

information is transacted to control the incredibly complex process

of mammalian development, with implications for the future of

biological research, medicine and biotechnology.

Both of these publications are part of a long-standing international

effort and represent an enormous body of work.

Prof. Claes Wahlestedt who is affiliated with Karolinska Institutet

in Sweden as well as Scripps Florida and the RIKEN Genomic Sciences

Center in Japan can be contacted for further information.

Peer reviewed publication and references

" Antisense Transcription in the Mammalian Genome " by S. Katayama, Y.

Tomaru, T. Kasukawa, K. Waki, M. Nakanishi, M. Nakamura, H. Nishida,

C.C. Yap, M. Suzuki, P. Carninci, Y. Hayashizaki, C. Wells, M. Frith,

T. Ravasi, K.C. Pang, J. Hallinan, J. Mattick, D.A. Hume, L.

Lipovich, P.G. Engstrom, Y. Mizuno, M.A. Faghihi, A. Sandelin, A.M.

Chalk, S. Mottagui-Tabar, Z. Liang, B. Lenhard and C. Wahlestedt in

Science, September 2nd 2005.

Reference URL

info.ki.se/article_en.html?ID=4323

SOURCE: http://www.alphagalileo.org