Evolution

Molecular evidence for the early colonisation of land by fungi and plants. Heckman, D. S. et al. Science 293, 1129–1133 (2001) [PubMed]

Fossil evidence indicates that the establishment of eukaryotes on land occurred around 480–460 million years (Myr) ago. Molecular clock data, based on a ribosomal gene, however, places this event at around 600 Myr ago. Now, an estimate of fungal divergence times based on the alignment of nuclear-encoded proteins pushes the origin of land eukaryotes to as early as 1,000 Myr ago.

Bioinformatics

Assembly of the working draft of the human genome with GigAssembler. Kent, W. J. & Haussler, D. Genome Res. 11, 1541–1548 (2001) [PubMed]

The draft human genome sequence data has been assembled using several approaches. One of the most successful and widely used assemblies is the “Golden Path” (http://genome.ucsc.edu) pioneered by these authors. This paper provides an overview of the algorithm that underlies the Golden Path assembly, shows how genome sequence data were combined with other types of data and gives useful insight into the strengths and weaknesses of the assembly.

Plant genetics

Plant growth homeostasis is controlled by the Arabidopsis BON1 and BAP1 genes. Hua J. et al. Genes Dev. 15, 2263–2272 (2001) [PubMed]

Organisms maintain their morphology under varying environmental conditions as a result of a poorly understood interplay between extrinsic and intrinsic factors. Hua et al. here identify a cell-membrane-associated, phospholipid-binding protein, BON1, and its partner BAP1 as factors that are necessary for normal Arabidopsis growth at low temperatures. BON1 and BAP1 co-ordinately regulate the rate of cell growth and division, possibly through their involvement in exocytosis or by controlling membrane lipid content.

Human genetics

Human mtDNA and Y-chromosome variation is correlated with matrilocal versus patrilocal residence. Oota, H. et al. Nature Genet. 29, 20–21 (2001) [PubMed]

Mitochondrial DNA often shows greater genetic diversity between human populations than does the Y chromosome, possibly because many human societies practice patrilocality, in which males remain at their birthplace but women migrate to join marriage partners. By collecting and analysing DNA from patrilocal and matrilocal tribes in Thailand, Oota et al. found that genetic variation does indeed strikingly correlate with patterns of residence, proving that social structure can influence human genetic diversity.