Friday, July 22, 2011

Jumping genes may tell why people have varied looks, disease risks

 Jumping genes may tell why people have varied looks, disease risks
Washington, Feb 5: A Johns Hopkins study has identified ''jumping genes'' in humans that may one day explain why people have such varied physical traits and disease risks.
Using bioinformatics to compare the standard assembly of genetic elements, the team revealed 1,016 new insertions of RIPs, or retrotransposon insertion polymorphisms, thereby expanding the catalog of insertions that are present in some individuals and absent in others.
Retrotransposons are travelling bits of DNA that replicate by copying and pasting themselves at new locations in the genome. Having duplicated themselves and accumulated over evolutionary history, transposable elements now make up about half of the human genome.
"In any individual, only between 80 to 100 retrotransposons are actively copying and inserting into new sites. We''re not only discovering where they are and who has which ones, but also finding out that they insert with a remarkable frequency: On the order of one in every 50 individuals has a brand-new insertion that wasn''t in their parents," said Haig Kazazian of the Johns Hopkins University School of Medicine.
The researchers recognized L1 retrotransposons because these actively jumping genes are human specific and almost exactly the same in sequence from one person to another.
The results appeared in the journal Genome Research. (ANI)