Volume 48 Issue 2, February 2016

Sanwen Huang, Detlef Weigel, Roger Beachy and Jiayang Li propose a regulatory framework for precision breeding with genome-edited crops. They argue that society should benefit from the latest advances in plant genetics and genomics.

The idea that pollinators are in large part responsible for the diversity of flowering plants dates back more than 150 years to Darwin's work, but even modern scientists have struggled to identify specific 'speciation genes' and determine how they influenced flower-pollinator interactions. A new study proposes that a series of mutations in a single gene controlling floral chemicals influenced pollinator preferences, likely resulting in speciation, bringing us closer to finding a speciation gene.

Plant pathogens can evolve new host specificities and overcome host resistances over surprisingly few generations, a process that is greatly accelerated by agricultural practices. A new study provides a striking example in which the rapid emergence of a new pathogen via introgressive hybridization mirrors the evolution of a hybrid cereal crop.

The Legionella genus includes opportunistic human pathogenic species that invade human cells using effector proteins that evolved during association with their natural amoeba hosts. A new study compares the genomes of 41 Legionella species to identify nearly 6,000 effectors, providing insight into these species' evolution and pathogenic lifestyles.

William Greenleaf, Michael Snyder, Carlos Araya and colleagues use density-based clustering methods on ~4,700 exomes from 21 tumor types to detect significantly mutated regions (SMRs), which show recurrent alterations in coding and noncoding elements and often associate with changes in gene expression and signaling. Mutation frequencies in SMRs demonstrate that distinct protein regions are differentially mutated across tumor types.

Matthew Hurles and colleagues sequence the genomes of three multi-sibling families and investigate the rates and spectra of germline mutation. Their analyses suggest that the mutation rate per cell division is higher during early embryogenesis than in post-pubertal spermatogenesis.

Iris Heid, Gonçalo Abecasis, Sudha Iyengar and colleagues report the results of a large genome-wide association meta-analysis of macular degeneration based on over 43,000 subjects. They identify 16 new risk loci, including some very rare coding variants.

Anneke den Hollander, Patsy Nishina and colleagues report heterozygous missense mutations in CTNNA1 in three families with butterfly-shaped pigment dystrophy. Ctnna1-mutant mice display a similar phenotype and show increased cell shedding and large multinucleated cells in the retinal pigment epithelium, suggesting defects in intercellular adhesion and cytokinesis.

Leif Andersson, Gregory Barsh and colleagues show that Dun camouflage color in horses is due to TBX3 expression in hair follicles, which causes asymmetric distribution of hair follicle melanocytes and reduced pigment deposition. They find that most domestic horses are more intensely pigmented (non-dun) owing to regulatory mutations impairing TBX3 expression in the hair follicle.

Cris Kuhlemeier and colleagues analyze the genetic basis for floral UV absorbance in Petunia species with either nocturnal or diurnal pollinators. They show that distinct mutations in the MYB-FL gene explain gain or loss of UV absorbance that correlates with bee-to-moth and moth-to-hummingbird pollination transitions.

Gil Segal, Howard Shuman and colleagues sequence the genomes of 38 Legionella species and analyze 5,885 predicted effector proteins. Their analysis identifies a core set of seven effectors shared by all 38 species and numerous previously unidentified conserved effector domains.

Matthew Meyerson and colleagues identify focal amplifications of regions harboring super-enhancers near KLF5, USP12, PARD6B and MYC in epithelial cancers. CRISPR/Cas9-mediated repression or deletion of a MYC enhancer in a lung adenocarcinoma cell line with the enhancer amplification results in downregulation of MYC and its target genes and impaired anchorage-independent and clonogenic growth.

Jessica Okosun, David Sabatini and colleagues identify recurrent RRAGC mutations in follicular lymphoma, resulting in activated mTORC1 signaling. The activating nature of the mutations, their existence within the dominant clone and their stability during disease progression support the potential of these mutations as promising candidates for targeted therapy.

Janey Wiggs, Jonathan Haines and colleagues identify three new susceptibility loci for primary open-angle glaucoma. The association signals map near genes implicated in ocular development (FOXC1), neurodegeneration (ATXN2) and mitochondrial function (TXNRD2).

Elodie Ghedin, Benjamin Cowling and colleagues quantify the frequency at which variants of influenza virus were transmitted between individual hosts during the 2009 H1N1 pandemic in Hong Kong. They find transmission of multiple variants between donor-recipient pairs and provide estimates of the number of viral particles that can infect and replicate within a host.

Beat Keller, Thomas Wicker and colleagues compare the genomes of 46 isolates of powdery mildew, Blumeria graminis. They find that B. graminis f. sp. triticale, a pathogen growing on triticale (a wheat × rye hybrid plant), is a hybrid of B. graminis f. sp. tritici and B. graminis f. sp. secalis, which grow on wheat and rye, respectively.

Natsuhiko Kumasaka, Andrew Knights and Daniel Gaffney develop a new statistical approach for association mapping that models genetic effects and accounts for biases in sequencing data in a single probabilistic framework. They apply this method to generate a map of chromatin accessibility QTLs and show how it can be used to fine-map regulatory variants and link distal regulatory elements with genes.

Iuliana Ionita-Laza, Kenneth McCallum and colleagues developed an unsupervised statistical approach, Eigen, that integrates different functional annotations into a single measure of functional importance for coding and noncoding variants. Their meta-score can outperform the recently proposed CADD score and can be applied to fine-mapping studies.