In this week's issue of Nature, a UK research team reports that they have identified large, rare chromosomal copy number changes linked to early obesity. In a group of 300 Caucasian individuals with early onset obesity, including 143 with developmental delays, the researchers found recurrent, rare deletions of various sizes affecting a chromosome 16 region called 16p11.2 — previously tied to conditions such as autism and mental retardation. The deletions all appear to affect a leptin- and insulin- signaling gene called SH2B1.
University of Salento researcher Maria Bozzetti and company explore how the Hsp90 chaperone protein helps prevent transposon-induced mutations in the Drosophila genome — and the how this protection relates to phenotypic variation in the fruit fly. Their results suggest Hsp90 interactions with a group of germline small RNAs called Piwi-interacting RNAs protect the genome from transposon mutagenic activity, while alterations in the gene coding for Hsp90 can lead to mutation and variation. "This indicates that Hsp90 mutations can generate new variation by transposon-mediated 'canonical' mutagenesis," they write.
In an early, online paper in Nature Genetics, a Swedish, Finnish, and American research team describe their use of genome-wide mapping to find systemic lupus erythematosus-related genes in dogs. By doing a GWAS involving 81 Nova Scotia duck tolling retrievers with SLE and 57 unaffected dogs genotyped at roughly 15,000 SNPs, the researchers identified five SLE-associated loci, which they subsequently validated by fine mapping in a larger group of dogs.
Meanwhile, an international team describes the first genome-wide association study of the malaria parasite Plasmodium falciparum. They used a custom microarray to interrogate nearly 3,500 SNPs in 189 culture-adapted P. falciparum strains developed from isolates collected in Asia, Africa, America, and Papua New Guinea. Their findings provide information on everything from parasite population structure to recombination hot- and cold-spots and drug resistance related genes in the P. falciparum genome. For more information, check out a related news story in our sister publication GenomeWeb Daily News.