By combining genome-wide association study results with single-cell transcriptomic data from the entire mouse nervous system, a team led by scientists from the Karolinska Institute identify the cell types underlying brain complex traits and uncover new details about the causes of Parkinson's disease. Among the findings, which appear in Nature Genetics, is an association of psychiatric disorders with projecting excitatory and inhibitory neurons. Parkinson's disease, meanwhile, was found to be genetically associated with cholinergic and monoaminergic neurons, as well as enteric neurons and oligodendrocytes, even at the earliest stages of the disease. The data, the study's authors write, suggest that the hallmark dopaminergic neuron loss in Parkinson's disease is at least partly due to intrinsic biological mechanisms. GenomeWeb has more on this, here.
A genomic and phenotypic analysis of modern maize published in Nature Genetics this week reveals new details about the significant increase in maize yield since breeding programs began in the first half of the 20th century. An international team led by scientists from South China Agricultural University collected 350 elite inbred maize lines representing multiple eras of germplasm from both China and the United States, phenotyping 15 key agronomic traits across the two countries. The investigators then sequenced the lines and used genome-wide association and selection scan methods to identify 160 loci underlying adaptive agronomic phenotypes and more than 1,800 genomic regions representing the targets of selection during modern breeding. "This work demonstrates the use of the breeding-era approach for identifying breeding signatures and lays the foundation for future genomics-enabled maize breeding," the authors write.