GM Organisms

Fitness effects of transgenic disease resistance in sunflowers. Burke, J. M. & Reiseberg, L. H. Science 300, 1250 (2003)

Could transgenes that escape from GM crops into wild populations confer a fitness advantage and spread quickly? Burke and Reiseberg crossed the transgene that confers resistance to white mold into wild sunflowers, to simulate the early stage of gene escape. The transgene provided protection against infection, but had no effect on seed output after inoculation with white mold. So, this particular transgene would diffuse neutrally after its escape.

Technology

Chips and solution detection of DNA hybridization using a luminescent zwitterionic polythiophene derivative. Nilsson, K. P. R. & Inganäs, O. Nature Mater. 2, 419–424 (2003)

Most methods for mutation detection rely on labelling of a nucleic acid or probe. This new technique removes the need for labelling, by detecting SNPs through the fluorescent signal that is produced when they interact with an electronic polymer. Unlike similar methods, this approach is still effective when the polymer is deposited and patterned on a surface, making it ideal for the development of high-throughput SNP detection microarrays.

Genomics

The male-specific region of the human Y chromosome is a mosaic of discrete sequence classes. Skaletsky, H. et al. Nature 423, 825–837 (2003)

Abundant gene conversion between palindromes in human and ape Y chromosomes. Rozen, S. et al. Nature 423, 873–876 (2003)

The full sequence of the male-specific region of the Y chromosome (MSY) has revealed an unanticipated number and diversity of genes. MSY euchromatic sequences are a mosaic of three classes: those closely related to the X chromosome, remnants of the autosomes from which the X and Y evolved and gene-rich groups of repeated sequences. The last class has eight large palindromes that contain many testis-specific genes and have arms with a minimum of 99.94% sequence identity. Recurrent gene conversion in the Y is responsible for maintaining intra-palindromic similarity.

Evolution

Stress-induced mutagenesis in bacteria. Bjedov, I. et al. Science 300, 1404–1409 (2003)

Using conditions that mimic the stresses encountered by bacteria in natural environments, this study shows that mutation rates increased in most of the 787 natural isolates of ageing E. coli colonies studied. It is still unclear what mechanisms are responsible for stress-induced mutations, but, regardless, they are likely to have an important influence on adaptive evolution in bacteria.