Research published in Science demonstrates the value of high-throughput sequencing in small RNA analysis

Solexa, Inc. (Nasdaq: SLXA) today announced that its researchers in collaboration with the Delaware Biotechnology Institute and the University of Delaware reported the most comprehensive analysis to date of the small RNA component of the transcriptome. The research, “Elucidation of the Small RNA Component of the Transcriptome,” was published in the September 2, 2005 issue of the peer-reviewed journal Science. Solexa’s
assay can be used to elucidate small RNAs in any plant or animal species, notably humans.

“Finding that small RNAs comprise a potent set of regulatory molecules in diverse organisms is among the most important discoveries in the past 10 years,” stated John West, Solexa’s chief executive officer. “This research is pioneering in its ability to characterize these important regulatory molecules on a genome-wide scale.”

Solexa’s technology has the advantage of producing highly accurate, reproducible and quantitative readouts of the full complement of activated genes and small RNAs, including genes expressed at low levels, without requiring advance knowledge of the genes or sequences of interest. Solexa performed this research in its Genomic Services business unit. The Company also intends to develop this small RNA assay for use with its next-generation sequencing platform, which is scheduled to be introduced to the market by the end of this year.

Using Solexa’s unique high-throughput sequencing technology, the study identified over 77,000 unique small RNAs in Arabidopsis plants, 10 times more than previously known. This study, funded by the National Science Foundation, generated more than two million short DNA sequences, known as signature sequences or sequence tags, to identify and quantify both known and novel small RNA molecules. Many regions of the Arabidopsis genome previously considered to be inactive or featureless were found to be sites of considerable small RNA
activity.

“The signature sequencing approach makes possible the study of global identity, regulation and function of small RNA populations in diverse organisms. This extensive small RNA data will help biologists understand small RNAs and their regulation,” said Blake Meyers, an Assistant Professor at the University of Delaware and a senior author on the study. “We have also released an enhanced version of our Arabidopsis MPSS website (http://mpss.udel.edu/at) to further facilitate public access and use of these data.”

“These experiments underscore the importance of studying the entire genome for evidence of small RNA activity. The newly discovered small RNAs that match to genes are exciting, but so are those that derive from relatively featureless regions between genes,” added Pamela J. Green, a professor at the University of Delaware and the Delaware Biotechnology Institute, another senior author on the study.

About small RNAs

The two major categories of small RNAs are microRNAs (miRNAs) and small interfering RNAs (siRNAs). Small RNAs function to silence genes by inhibiting the synthesis or function of mRNA. Deficiencies in small RNA production can have a profound effect on development, and small RNAs have been associated with other important biological processes such as stress responses. In addition, recent data suggests a possible role for small RNA profiling in cancer diagnostics.

Solexa, Inc. is developing and preparing to commercialize a new genetic analysis instrument system which will be used to perform a range of analyses including whole genome resequencing, gene expression analysis and small RNA analysis. We expect the first generation of Solexa’s new technology to generate over a billion bases of DNA sequence per run and to enable whole genome resequencing below $100,000 per sample, making it the first platform to reach this important milestone. Solexa's longer-term goal is to reduce the cost of human resequencing to a few thousand dollars for use in a wide range of applications from basic research through clinical diagnostics. The Company expects to introduce its first instrument system by the end of 2005.