Multifactorial genetics

Identification of wound healing/regeneration quantitative trait loci (QTL) at multiple time points that explain seventy percent of variance in (MRL/MpJ and SJL/J) mice F2 population. Masinde, G. L. et al. Genome Res. 11, 2027–2033 (2001) [PubMed]

To identify key genes involved in wound healing, Masinde et al. crossed two mouse strains together that have markedly different wound-healing rates. They then carried out genome-wide scans in F2 mice at different time points after ear punching and found ten wound-healing quantitative trait loci (QTL), eight of which are new. Some QTL are involved at all stages of wound healing, and epistatic interactions between loci also occur.

Comparative genomics

Comparative genomics between rice and Arabidopsis shows scant collinearity in gene order. Liu, H. et al. Genome Res. 11, 2020–2026 (2001) [PubMed]

Arabidopsis and rice are distantly related, but their genomic similarities could help in transferring information, such as gene location, from the smaller, sequenced Arabidopsis genome to the larger rice genome. To investigate the degree of conserved gene order between these two species, Liu et al. compared 126 annotated and mapped rice BAC sequences with the Arabidopsis sequence. Gene order was conserved in some regions, but these are quite small, indicating that the Arabidopsis genome might not be useful for assembling the rice genome.

Human genetics

Type 2 diabetes and three Calpain-10 gene polymorphisms in Samoans: no evidence of association. Tsai, H.-J. et al. Am. J. Hum. Genet. 69, 1236–1244 (2001) [PubMed]

In 2000, three calpain-10 (CAPN10) single nucleotide polymorphisms (SNPs) were found to be associated with increased susceptibility to type 2 diabetes in Mexican Americans. Tsai et al. have now tested the association of these SNPs with the disease in Samoans, among whom it is highly prevalent. No association was found, perhaps because CAPN10 is a susceptibility gene only in certain ethnic groups or because their sample size was too small to detect its effects.

Technology

Transgenic DNA introgressed into traditional maize landraces in Oaxaca, Mexico. Quist, D. & Chapela, I. H. Nature 414, 541–543 (2001) [PubMed]

Transgenic DNA has been found in wild strains of maize in the Oaxaca region of Mexico. Despite a moratorium in Mexico on the planting of transgenic maize since 1998, these authors have found clear evidence of transgenic DNA in 5 of 7 landraces tested, which they believe was introduced multiple times. This finding has implications for the maintenance of food and crop diversity.