Volume 48 Issue 1, January 2016

Two new studies show how highly divergent modes of male reproduction in a wading bird are controlled by alternate alleles at a single locus encompassing a 4.5-Mb inversion in the genome. The locus is an example of a 'supergene' controlling multiple complex phenotypes.

The plant circadian clock is a complex network of genes crucial for plant survival. A new study finds that domestication gradually slowed down the circadian clock of tomato via selection on two major genes—one that delayed phasing of the clock with daylight, whereas the other induced a longer period.

Iron is essential in multiple cellular processes and is especially critical for cellular respiration and division. A new study identified a mutation affecting the iron import receptor TfR1 as the cause of a human primary immunodeficiency, illuminating the importance of iron in immune cell function.

Kerstin Meyer and colleagues analyze a breast cancer gene regulatory network generated using publicly available expression and ChIP-seq data sets. They identify a cluster of 36 regulons that are significantly enriched for known breast cancer risk-associated genes and propose the use of regulon activity for patient stratification.

Yaniv Erlich and colleagues report a genome-wide survey of the contribution of short tandem repeats (STRs) to gene expression in humans and identify 2,060 significant expression STRs (eSTRs). They find that eSTRs contribute 10–15% of the cis heritability mediated by all common variants and are associated with various clinically relevant phenotypes.

Christopher Haiman, Bogdan Pasaniuc, David Reich and colleagues report a major role for low-frequency variation in the risk for prostate cancer. They show that alleles with >1% minor allele frequency contribute an order of magnitude more to risk for prostate cancer than these alleles do to overall genetic variation.

Andrew Jackson, Grant Stewart, Bernd Wollnik and colleagues identify TRAIP mutations in three patients with primordial dwarfism. They show that TRAIP is involved in DNA damage response during genome replication and is necessary for efficient cell cycle progression.

Renee Reijo Pera, Vittorio Sebastiano and colleagues identify three human pluripotency-associated transcripts (HPATs) that function in preimplantation development. They find that these three HPATs are also required for efficient nuclear reprogramming and that one, HPAT5, interacts with let-7 to modulate gene expression during reprogramming and differentiation.

Paul Khavari and colleagues analyze tumor genomes to identify snoRNAs showing frequent copy number loss of adjacently encoded snoRNAs SNORD50A and SNORD50B. These snoRNAs directly bound K-Ras and their loss leads to increased activity of both wild-type and oncogenic K-Ras and is associated with reduced survival.

Murat Günel and colleagues use an integrated genomic approach to analyze the malignant progression of IDH1-mutant gliomas. They observe nonlinear clonal expansion of the original tumors and identify oncogenic pathways driving progression, including activation of MYC and RTK-RAS-PI3K pathways and epigenetic silencing of developmental transcription factors.

Ivona Aksentijevich and colleagues identify heterozygous loss-of-function mutations in TNFAIP3 (encoding A20) in six unrelated families with early-onset systemic inflammation. Affected individuals exhibit increased expression of NF-κB–mediated proinflammatory cytokines, consistent with the established role of A20 as a potent inhibitor of the NF-κB signaling pathway.

Raif Geha, Louis Kunkel, Waleed Al-Herz and colleagues report a mutation in TFRC (encoding transferrin receptor 1, TfR1) that causes combined immunodeficiency characterized by impaired function of T and B cells in homozygous patients. Iron citrate rescued the lymphocyte defects in patient-derived cells and in a mouse model, demonstrating the importance of TfR1-mediated iron internalization in adaptive immunity.

Terry Burke, Mark Blaxter, David Lank and colleagues report a reference genome sequence of the ruff and analysis of the three distinct male morphs of this bird species. They identify a ‘supergene’ consisting of a fixed inversion in two of the morphs and identify candidate reproductive trait genes in this region.

Leif Andersson and colleagues report the genome sequence of the ruff, a bird species with three male morphs with different reproductive strategies. Satellite and faeder morphs differ from the common independent morph by a 4.5-Mb inversion that occurred approximately 3.8 million years ago, and multiple genetic changes within this inverted region are associated with the satellite and faeder morphs.

José M. Jiménez-Gómez and colleagues report that the circadian clock of cultivated tomato was quantitatively slowed during domestication compared to its wild relatives, based on measurements of circadian leaf movements. They map QTL for phase and period, and identify the causal gene, EID1, underlying the phase QTL.

Matthew Stephens and colleagues present a method for visualizing geographic patterns in genetic population structure. They apply this method to data from elephant, human and Arabidopsis thaliana populations and illustrate its potential to highlight barriers and corridors to gene flow.