Mice in which the gene for the cannabinoid receptor has been knocked out eat less than normal.

Plants have evolved a number of cold-response genes encoding proteins that induce tolerance to freezing, alter water absorption and initiate many other low temperature induced processes. In the 1 April Genes and Development, Jian-Kang Zhu and colleagues of the Department of Plant Sciences, University of Arizona, shed light on how these genes are regulated.Lee et al report that the protein HOS1 negatively regulates cold-response genes in Arabidopsis. At low temperatures, HOS1 relocalises from the

might be able to differentiate between real and imagined fear.

The first wave of programmed cell death in the early mouse embryo requires apoptosis-inducing factor (AIF) and not caspases.

Neurofibromatosis type 1 (NF1) is an inherited neurological disorder that affects 1 in 3,500 people worldwide. It is caused by mutations in the NF1 gene, which encodes neurofibromin, a protein involved in the Ras signalling pathway. Patients have tumours of neural origin and many have learning difficulties.Previous attempts to knock out the NF1 gene have been unsuccessful because the mutant mice die as embryos. Now, a team of researchers led by Luis Parada of the University of Texas Southwestern

Tobacco plants emit chemical signals in response to caterpillar attack. Ovipositing moths exploit these signals to reduce competition for their offspring.

Some people perceive colours when they see letters or numbers. A study sheds light on this unusual phenomenon.

Critically important sensory surfaces, such as the fingertips, are allocated more cortical brain space. Research into the development of sensory appendages in moles helps explain how cortical magnification arises.

In 20 March Current Biology, Kai Zinn and colleagues at the California Institute of Technology, describe a genetic screen for identifying genes involved in axon guidance and synapse formation (Curr Biol 2001, 11:417-430).They started with a set of 2293 Drosophila lines, each carrying an 'EP element' inserted at known sites throughout the genome. An EP element is a transposable P element containing a basal promoter and 14 copies of the yeast UAS sequence, which responds to the transcription facto

Amoebae are capable of primitive social interaction and co-operation.

The enzyme Cox-2 mediates inflammatory pain at sites of injury. Two studies now show that local inflammation can also cause pain in neighbouring areas by upregulating Cox-2 expression in the central nervous system.

gene and with defects in chromosome segregation. Two studies now show that microtubules need APC for proper attachment when they pull chromosomes apart.