Same gene is different in different tissues

Washington, Nov 3 (IANS) A gene is known to produce slightly different versions of the same protein by skipping or including certain sequences from the messenger RNA, knowledge that may be significant in the fight against cancer.

Now, a Massachusetts Institute of Technology (MIT) team has shown that this phenomenon, known as alternative splicing, is far more prevalent and varies more between tissues than was previously suspected.

About 94 percent of human genes generate more than one form of their protein products, said the MIT team. Scientists' previous estimates ranged from a few percent 10 years ago to 50-plus percent more recently.

'A decade ago, alternative splicing of a gene was considered unusual, exotic. . . but it turns out that's not true at all - it's a nearly universal feature of human genes,' said Christopher Burge, co-author of the paper and an associate professor of biology and viological engineering at MIT.

Burge and his colleagues also found that in most cases the mRNA produced depends on the tissue where the gene is expressed. The work paves the way for future studies into the role of alternative proteins in specific tissues, including cancer cells.

They also found that different people's brains often differ in their expression of alternative spliced mRNA isoforms, according to an MIT release. The findings were reported in Sunday online edition of Nature.