Wednesday, July 25, 2007

The Out of Nowhere Gene

New genes have been for decades believed to created from existing genes. New research that some new genes pop up Out of Nowhere. Researchers studying the Drosophilia fruit fly have discovered a gene without peers.

A new gene, called hydra, exists in only a small number of species of Drosophila fruit flies. Research indicates that the gene was created roughly 13 million years ago, when it is believed that the melanogaster subgroup species diverged from a common ancestor.

In addition to the appearance of new gene, some early evidence also shows that this new gene is functional i.e. not "junk" DNA. and may express itself as a protein involved in late stages of sperm cell development (spermatogenesis). Other scientists working with functional genes in any species also are expressed in male testes and appear related to spermatogenesis.

One problem that the researchers are working on is how the hydra gene was created. They believe that it came out of nowhere. Some speculate that the gene may have developed from a piece of DNA junk called a transposable element which some refer to as a "jumping gene". It may have been inserted into the genome by a virus. These transposons are known to copy and insert themselves into DNA sequences. One theory is that when a transposon sits next to a gene it carries part of the gene sequence it was next to and then if it jumps to a new location it inserts that gene sequence in the new location. Current thinking is that transposable gene elements appear to have no function or may be harmful and are eliminated by natural selection, however, other researchers believe that some transposons may be a source for creating new functional genes as well.

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