No one really understands why activation of the tumor suppressor p53 sometimes leads to cell-cycle arrest and sometimes induces an apoptotic program. It has been proposed that post-translational modifications (phosphorylation and acetylation) induced by genotoxic stress affect the DNA binding affinity of p53. In the January 8 issue of Proceedings of the National Academy of Sciences, Kaeser and Iggo suggest that such models should be reassessed in light of their results using chromatin immunoprec

The retina contains neuronal cells (including photoreceptors) and non-neuronal retinal pigment epithelium (RPE). In January 8 Proceedings of the National Academy of Sciences, Dror Sharon and colleagues at Harvard Medical School describe characterisation of gene expression profiles in the human eye using the SAGE (serial analysis of gene expression) technology (Proc Natl Acad Sci USA 2002, 99:315-320).They prepared SAGE libraries from the peripheral retina, the macula and the RPE of two individua

The Plasmodium yoelii yoelli genome contains around 35 genes encoding 235 kD rhoptry proteins (Py235) that are involved in erythrocyte invasion and parasite virulence. In the January 11 issue of Science, Preiser et al. describe the transcription pattern of py235 genes during the parasite's life cycle and their role in cell invasion (Science 2002, 295:342-345).Immunofluorescence analysis using antibodies recognizing distinct Py235 proteins revealed differences between pre-erythrocytic and erythro

Large-scale purification and mass spectrometry has been used to characterize hundreds of multiprotein complexes in yeast.

Gene therapists have developed a RNA-mediated technique for correcting gene defects that cause cystic fibrosis.

The fourth chromosome of Drosophila melanogaster was believed to be free from variation and meiotic recombination, leading to several theories about its selection and evolution. In the January 4 Science, Wen Wang and researchers at the University of Chicago challenge these theories with their discovery of regions of variation along the chromosome (Science 2002, 295:134-137).They analysed nucleotide sequence around the toy gene locus from many fly collections worldwide. The observation that there

Combined functional genomics approaches help to identify novel genes involved in the DNA damage response pathway in nematodes.

Following the completed draft of the human genome sequence, there is renewed interest in the genetic differences between species and, particularly, in what makes us human. In 4 January Science, Asao Fujiyama and colleagues at the RIKEN Genomic Sciences Center, Japan present a first-generation human-chimpanzee comparative genome map (Science 2002, 295:131-134).They used over 77,000 chimp bacterial artificial chromosomes (BAC) and aligned end-sequences with the human genomic sequence. The BAC clon

Finding genes within genomic sequence remains a major challenge, even for a genome that has undergone extensive annotation such as that of the yeast Saccharomyces cerevisiae. In January Nature Biotechnology, Anuj Kumar and colleagues at Yale University describe an integrated genomics approach for gene hunting (Nat Biotechnol 2002, 20:58-63).Kumar et al. performed a large-scale insertional mutagenesis screen using a modified transposon as a LacZ-reporter gene-trap. Candidate genes were then verif

The 'Year of the Genome' ended with the publication of a tiny genome, that of the marine chordate Oikopleura dioica. Oikopleura is a small pelagic chordate that measures just 5mm. It is easy to culture and has a short life cycle (2-4 days) and high female fecundity (around 300 oocytes). In 21 December Science, Hee-Chan Seo and colleagues reported the genome sequence of O. dioica (Science 2001, 294:2506).They used large-scale shotgun sequencing to assemble contigs covering 32.6 Mb. The total geno

The three-spined stickleback (Gasterosteusaculeatus) is a teleost fish that has undergone rapid adaptive evolution and speciation within the last 15,000 years. The benthic species has greatly reduced body armour, increased body depth and fewer gill rakers than the limnetic species, which more closely resemble an ancestral marine fish. In the December 20/27 Nature, Peichel et al. report the generation of a genome-wide linkage map for G. aculeatus (Nature 2001, 414:901-905).They collected 1,176 cl

locus encodes a death-domain adaptor protein associated with hypohidrotic ectodermal dysplasia.