DNA microarray analysis has been used to define gene-expression profiles following treatment with antisense oligonucleotides.

It has been proposed that isoforms of Drosophila mod(mdg4) result from the trans-splicing of independent mRNA transcripts derived from both anti-parallel DNA strands. In the August 14 Proceedings of the National Academy of Sciences, Rainer Dorn and researchers at the Martin Luther University, Halle, Germany, provide proof for trans-splicing of mod(mdg4) transcripts in transgenic flies (Proc Natl Acad Sci USA 2001, 98:9724-9729).They characterized 26 different classes of mod(mdg4) transcripts all

The search is on to identify and locate neural stem cells (NSCs). In the August 16 issue of Nature, Rodney Rietze and colleagues at The Walter and Eliza Hall Institute for Medical Research Australia, report the isolation of a pluripotent stem cell population from mouse brains (Nature 2001, 412:736-739).They performed a series of enrichment steps to purify NSCs from the ependymal and subventricular zones of the lateral ventricular walls. Flow cytometry was used to select a population expressing l

Ordered acetylation of the HMGI(Y) protein controls enhanceosome stability and switches on gene expression.

Chromosomes are composed of functionally distinct domains separated by chromatin boundaries. In the August 10 Science, Noma et al. define the boundaries of the heterochromatin domain at the mating-type locus (mat) in fission yeast (Science 2001, 293:1150-1155).They used chromatin immunoprecipitation (ChIP) and PCR analysis to scan the entire mat region (about 47 kilobases). Methylation of lysine 9 of histone H3 and the Swi6 protein were both enriched in a 20kb interval that contains the mat2/3 s

Microbial comparative genomics provides insights into gene function, bacterial speciation and evolutionary relationships. In the August 14 Proceedings of the National Academy of Sciences, Murray et al. describe an approach to explore genome diversity and relatedness in the absence of complete sequence information (Proc Natl Acad Sci USA 2001, 98:9853-9858).They used sequence information from the Shewanella oneidensis strain MR-1 to construct DNA microarrays containing over 100 full-length open r

Argonaute2, a component of the nuclease complex that carries out gene-silencing during RNAi, has been biochemically purified.

The protozoan parasite Plasmodium causes malaria, the most serious parasitic disease in humans. The identification of proteins expressed at the infectious sporozoite stage is important for the selection of potential vaccine candidates. In the August 14 Proceedings of the National Academy of Sciences, Stefan Kappe and colleagues from the New York University School of Medicine describe attempts to characterize the sporozoite transcriptome (Proc Natl Acad Sci USA 2001, 98:9895-9900).They construct

In the August 3 Science, Laxminarayana Devireddy and colleagues from the University of Massachusetts Medical School report the use of DNA microarrays to identify genes whose expresssion is induced during apoptosis (Science 2001, 293:829-834). They studied cell death of a mouse pro-B lymphocytic cell line upon withdrawl of interleukin-3. The gene that showed the largest induction (12.6-fold) was 24p3, which encodes a lipocalin. Lipocalins are small secreted proteins, and Devireddy et al. found th

protein-fragment complementation assay can monitor protein-protein interactions in living plant cells.

When primary murine fibroblasts are placed in culture they exhibit replicative senescence, associated with the induction of cell-cycle inhibitors. The Ink4a-Arf locus encodes two proteins, p16Ink4a and p19Arf, which regulate the cell cycle by modulating the activities of pRb and p53, respectively. In the Early Edition of the Proceedings of the National Academy of Sciences, Randle et al. describe the role of p19Arf in preventing immortalization of bone-marrow-derived preB cells and macrophages (P

In the August issue of Nature Biotechnology, Francesca Sotrici and colleagues from the National Institute of Environmental Health Sciences describe how to commit the perfect murder (Nature Biotechnology 2001, 19:773-776). "Delitto perfetto" (Italian for perfect murder) is the name they gave to a two-step, cloning-free, technique that creates desired mutations, be they simple nucleotide replacements, precise insertions or large deletions. The first step involves integration of a counterselectable