DNA recombination

Global mapping of meiotic recombination hotspots and coldspots in the yeast Saccharomyces cerevisiae. Gerton, J. L. et al. Proc. Natl Acad. Sci. USA 97, 11383–11390 (2000)

Microarray experiments usually involve a comparison of gene expression profiles, but Gerton et al. have used microarrays to assay the distribution of recombination events over the entire yeast genome at single-gene resolution. The strongest association seen is between hotspots of recombination and elevated G+C content, and the goal is now to relate the positions of hotspots — and coldspots — to chromosome structure. [PubMed]

Gene expression

Genomic analysis of gene expression in C. elegans. Hill, A. A. et al. Science 290, 809–812 (2000)

Comparative genomics and microarray analysis of gene expression are a potent combination. In this first, comprehensive analysis of gene expression in animal development, the authors find that Caenorhabditis elegans genes conserved in Drosophila melanogaster and yeast tend to be expressed at higher and more uniform levels during development. Worm-specific genes, however, are more likely to be developmentally regulated — observations consistent with the view that ancient genes deal with the `core' functions, whereas newer genes see to worm-specific developmental processes.[PubMed]

Technology

Specific mutations induced by triplex-forming oligonucleotides in mice . Vazquez, K. M. et al. Science 290, 530–533 (2000)

One gadget missing from the geneticist's toolkit is a technique to introduce targeted mutations into somatic cells. Vazquez et al. have achieved this in the somatic cells of adult mice using triplex-forming oligonucleotides (TFOs), which recognize and bind to specific duplex DNA sequences. TFO's seem to increase the hypermutability of G-rich, recombinogenic sites and, although their mechanism of action remains unknown, their mutagenic activity depends on a functioning nucleotide-excision–repair system. [PubMed]

Disease model

Identification of genes that modify ataxin-1-induced neurodegeneration . Fernandez-Funez, P. et al. Nature 408, 101–106 (2000)

The power of using flies to study human neurodegenerative disease is convincingly illustrated in this study, in which the authors expressed the human SCA1 gene, encoding transcripts with and without expanded polyglutamine repeats, in the Drosophila melanogaster eye. They then used these flies in genetic screens to identify modifiers of the eye neurodegeneration phenotype. The modifiers they identified point to new mechanisms of polyglutamine pathogenesis and implicate protein folding and protein clearance in SCA1 aetiology. [Abstract]