In Nature Genetics this week, an international research team presents the fully assembled genome of modern durum wheat, a cereal grain primarily used for pasta production that evolved from domesticated emmer wheat. Genome-wide genetic diversity analyses of the assembly revealed changes imposed by thousands of years of empirical selection and breeding The researchers uncovered a gene encoding a metal transporter with a non-functional variant that causes high accumulation of cadmium in grain. This allele, they write, is widespread among durum cultivars, but is not detected in wild emmer accessions. It increased in frequency during the plant's domestication and could exert some beneficial effects on plant fitness. The findings, the authors state, may prove useful for "future innovation for the wheat scientific community and the breeding sector." The Scan has more on this, here.
And in Nature Human Behavior, scientists from the US and UK describe a new method for analysing the joint genetic architecture of complex traits. Called genomic structural equation modelling — or genomic SEM — the approach synthesizes genetic correlations and single-nucleotide polymorphism heritabilities inferred from genome-wide association study summary statistics of individual traits from samples with varying and unknown degrees of overlap. According to the researchers, it enables modeling of multivariate genetic associations among phenotypes, the identification of variants with effects on general dimensions of cross-trait liability, the calculation of more predictive polygenic scores, and the identification of loci that cause divergence between traits. To demonstrate genomic SEM, the team performed a joint analysis of summary statistics from five psychiatric traits.
And in Nature Microbiology, researchers from Harvard Medical School and Boston University report a CRISPR interference-based approach for generating functional genomic data on Vibrio natriegens, a Gram-negative bacterium that has potential to be a model for molecular biology due to its short generation time. The investigators developed a pooled genome-wide CRISPRi screen to identify a minimal set of genes required for rapid wild-type growth, finding core genes comprising putative essential and growth-supporting genes that are enriched for respiratory pathways. The screen also refines metabolic pathway annotations by distinguishing functional biosynthetic enzymes from those predicted on the basis of comparative genomics. This work, they conclude, "provides a broadly applicable platform for high-throughput functional genomics to accelerate biological studies and engineering of V. natriegens."