In the Early Edition of the Proceedings of the National Academy of Sciences, Andrew Su and collaegues describe high-throughput gene-expression analysis of the mouse and human transcriptomes in different tissues (Proc Natl Acad Sci USA 2002, 10.1073/pnas.012025199).Su etal. performed oligonucleotide hybridisation experiments on samples from 46 human and 45 mouse tissues of diverse origin. They found that 6% of genes are ubiquitously expressed, and individual samples express 30-40% of genes; almos

Now that the Arabidopsis thaliana genome has been sequenced, plant biologists are turning their efforts to genome annotation. In a 21 March report on the Sciencexpress website, Motoaki Seki and colleagues from the RIKEN Institute in Japan, describe a large-scale analysis of full-length Arabidopsis cDNA libraries (Sciencexpress 2002 10.1126/science.1071006).Seki et al. isolated over 150,000 RIKEN Arabidopsis Full-Length (RAFL) cDNA clones, sequenced the ends and clustered them into almost 15,000

An RNA interference (RNAi) screen has been used to find genes involved in RNA interference.

In the March 19 Proceedings of the National Academy of Sciences, Mohammed Kashani-Sabet and colleagues describe the use of plasmid-based ribozymes as functional genomics tools to unravel complex phenotypes, such as cancer metastasis (Proc Natl Acad Sci USA 2002, 99:3878-3883).Kashani-Sabet et al. reasoned that ribozyme-based gene targeting in mice might overcome experimental problems associated with transgenesis and lethal knockout phenotypes. They tested the use of systemic administration of ca

A reverse transcriptase enzyme and genomic repeat sequences coordinate a tropic switch in a bacteriophage.

'CpG islands' are often associated with promoter regions. A CpG island has traditionally been defined as a 200 bp region of DNA with a G+C content over 50% and an observed/expected CpG ratio of 0.6 or more. In the March 19 Proceedings of the National Academy of Sciences, Daiya Takai and Peter Jones of the University of Southern California describe a re-evaluation of CpG islands using the finished sequences of human chromosomes 21 and 22 (Proc Natl Acad Sci USA 2002, 99:3740-3745).They developed

Discussion of the potential of using pluripotent stem cells for tissue transplantation has raised issues about the frequency and types of spontaneous mutation in these cells. In the March 19 Proceedings of the National Academy of Sciences, Rachel Cervantes and colleagues from the University of Cincinnati, Ohio, report a study of spontaneous and induced mutagenic events in murine embryonic stem (ES) cells (Proc Natl Acad Sci USA 2002, 99:3586-3590).Cervantes et al. used a murine model with a disr

Individuals with mutations in the ATM gene develop ataxia-telangiectasia, a neurodegenrative disorder characterized by immunological defects and cancer predisposition. In an Advanced Online Publication from Nature Genetics, Franco Pagani and colleagues describe a new kind of ATM mutation that leads to an unusual splicing defect (Nat Genet 2002, DOI:10.1038/ng858).The mutant ATM allele contains a four-nucleotide deletion (GTAA) within intron 20. This deletion results in the inclusion of a 65 nucl

Analysis of differentiation-dependent transcription reveals that the pre-initiation complex (PIC) can assemble before chromatin remodeling.

There has been much debate about whether DNA sequences may, or indeed should, be patented. This issue has prevented the release and dispersal of much genomic data by commercial genomics companies. In the March issue of Nature Biotechnology, Willem Stemmer of Maxygen Inc. in California, offers a harmonious solution for the sharing of DNA sequences while maintaining intellectual property (IP) protection (Nat Biotechnol 2002, 20:217).While the patentability of DNA is in question, music and original

Unmodified starches present a problem to the frozen food industry as they tend to result in poor texture upon cycles of freeze-thawing. In March Nature Biotechnology, Stephen Jobling and colleagues describe a genetic solution to generating freeze-thaw-stable starch (Nat Biotechnol 2002, 20:295-299).Jobling et al. created potato plants with reduced levels of the three starch synthase genes using triple antisense technology. The authors showed that the there was an efficient downregulation of the

In the March 5 Proceedings of the National Academy of Sciences, Pascal Braun and colleagues describe a methodology to perform high-throughput purification of human proteins using several affinity-tags (Proc Natl Acad Sci USA 2002, 99:2654-2659).Braun et al. exploited the Gateway recombinational cloning system that employs a versatile 'master' vector for easy transfer into different expression vectors. They chose a test set of 32 human genes and expressed them in four different vectors with diffe