In Nature this week, a multinational team of researchers publishes an analysis of the bread wheat genome, identifying genes associated with crop productivity and finding that these families have grown in size, potentially because of selection during domestication. Despite the importance of bread wheat to global human populations, the size and polyploid complexity of its genome has stymied genomic analysis. Using whole-genome shotgun sequencing, the team found more than 90,000 genes and assigned them to ancestral grass genomes. Additionally, several classes of genes involved in energy harvesting, metabolism, and growth were uncovered. The analyses, "coupled with the identification of extensive genetic variation, provide a resource for accelerating gene discovery and improving this major crop." For more on this study, see this article from our sister publication GenomeWeb Daily News.
Also in Nature, a University of Washington team reports on the results of an analysis of the exomes of more than 6,500 European Americans and African Americans, conducted as part of the National Institutes of Health's Exome Sequencing Project. The investigators found that the spectrum of protein-coding variation in the modern human genome is quite different than that of 5,000 years ago, with about 73 percent of mutations arising within the past 5,000 years to 10,000 years. The study suggests that the increased mutational capacity of modern human populations has influenced the burden of single-gene disorders, but has also likely yielded beneficial genetic changes.
In Nature Genetics, Chinese researchers publish a draft genome of watermelon, Citrullus lanatus, containing 23,440 predicted protein-coding regions. Resequencing of 20 watermelon accessions representing three different subspecies of C. lanatus produced "numerous haplotypes and identified the extent of genetic diversity and population structure of watermelon germplasm," while genome regions preferentially selected during domestication and disease-resistance genes lost during this process were also identified. GenomeWeb Daily News also has more on this study here.