that may affect mate discrimination and sexual isolation.

A promoterless vector encoding a green fluorescent protein-nitroreductase fusion protein offers a versatile approach to trapping genes.

A computational approach is being used to identify disease-related regions in the mouse genome.

PCR analysis sheds light on the history of the pathogen that caused the Irish potato famine.

SNPs (single nucleotide polymorphisms) are valuable markers for mapping mutations and human disease-related genes. In the June issue of Nature Genetics, Wicks et al. describe a SNP-based strategy for rapid mapping in the C. elegans genome (Nature Genetics 2001, 28:160-164). They sequenced the entire genome of the CB4856 Hawaiian worm isolate and compared it with the standard laboratory wild type strain (Bristol N2). This alignment identified 6,222 potential polymorphisms, more than half of which

A recent report linked the human NOTCH4 locus with susceptibility to schizophrenia. In the June issue of Nature Genetics, two reports cast doubt on the NOTCH4-schizophrenia association. Sklar et al. conducted a large-scale study involving 519 parent-offspring trios in three independent families (compared to 80 trios in the original linkage study; Nature Genetics 2001, 28:126-128). Extensive association analyses failed to confirm the previous linkage results. McGinnis et al. analysed (CTG)n and

Animal anti-apoptotic genes can defend transgenic plants against pathogen attack.

Artificial neural networks can help in applying microarray data to tumour diagnosis.

Single-stranded oligonucleotides may provide a new tool for homologous recombination and genome modification.

Serial passaging in mouse lungs selects for virulent variants of influenza A virus that result from several mutations.

Deoxyribonuclease II (DNase II) is a lysosomal DNase that has been implicated in the degradation of DNA in apoptotic cells. In the May 25 Science, Kawane et al. report the analysis of mice lacking a functional DNase II protein (Science 2001, 292:1546-1549). No DNase II-null mice survived until birth. Mutant embryos developed anemia at embryonic days 12.4-14.5 and had dramatically reduced numbers of mature erythrocytes. Transplantation of DNase II-null fetal liver cells into irradiated mice gener

The RNA interference (RNAi) technique has been used to disrupt gene function in a range of model organisms, but its use in mammalian cells has been problematic. RNAi involves the ribonuclease-III-catalysed digestion of specific double-stranded RNA into 21-22 nucleotide small interfering RNA (siRNA) species. In the May 24 Nature, Elbashir et al. report the application of RNAi in cultured mammalian cells (Nature 2001, 411:494-498). They designed 21-nucleotide siRNA duplexes, with symmetric two-nuc