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The authors show that increased Xist RNA levels can induce de novo silencing of genes that normally escape X inactivation. SPEN depletion prevents the silencing of escape genes upon Xist RNA overexpression in neural progenitors.

Duncan Odom and colleagues map Pol III occupancy genome-wide in liver tissue from six mammals. The analysis showed variable binding of Pol III at individual tRNA genes that nevertheless led to conserved expression of amino acid isotypes.

Mutagenic lesions such as those that give rise to cancer frequently segregate—unrepaired—during cell division, resulting in phasing of multiple alleles across generations of daughter cells and consequent tumour heterogeneity.

Here the authors find a genetic alteration in the popular “Four Core Genotypes” mouse model that is used to distinguish sex-biased phenotypes caused by sex chromosomes and gonads. This alteration increases the expression of some X-linked genes, which might confound the interpretation of the model.

Long noncoding RNAs (lncRNAs) regulate key steps of cell division. Here, the authors perform a comprehensive RNAi imaging screen targeting more than 2,000 human lncRNAs, and suggest a role of chromatin-associated linc00899 in regulation of cell division by suppressing the transcription of microtubule-binding protein TPPP/p25.

Low IVF efficiency is in part due to fertilization failure, though little is known about why retrieved oocytes vary in this regard. Here they show that oocyte maturation and nurse cell contacts are disrupted by superovulation and aging, and propose nurse cell markers to predict success of fertilized eggs.

Here the authors show that genetic changes between species often alter gene expression in a cell type-specific manner. Most of this variability is driven by locally functioning cis-acting variation, and this contributes to the speed at which cell types accumulate expression changes.

A single-cell-based approach allows the daughters of a damaged cell to be separately tracked following single mitotic events. This technique highlights the different ways in which ultraviolet light and reactive oxygen species cause mutagenesis.

How strand-asymmetric processes such as replication and transcription interact with DNA damage to drive mechanisms of repair and mutagenesis is explored.

A technique that combines retrograde axon tracing with single-cell transcriptomics is used to characterize neurons innervating pancreatic ductal adenocarcinoma and healthy pancreas, providing insight into the role of neural connections in cancer progression.

The authors show that the lncRNA-derived microprotein SMIMP, which is shown to promote tumor formation, regulates cohesin core subunit binding to cis-regulatory elements and alters the expression of tumor-suppressive cell cycle regulators.

The transcriptional regulation of murine spermatogenesis is not well understood. Here, the authors use single-cell and bulk RNA-Sequencing of juvenile and adult mice to characterise somatic and germ cell development, and chromatin profile the X chromosome to show that spermatid-specific genes are repressed by H3K9me3 during meiosis.

“Variation in the noncoding regulatory sequences in the genome plays important roles in human disease and evolution. Here, the authors use F1 mouse hybrids to shed light on the regulatory mechanisms mediating transcription factor binding, chromatin state and gene expression in mammalian cells.”

LncRNAs regulate gene expression via their RNA product and through transcriptional interference. Here, Stojic et al.uncouple these functions by using multiple siRNAs against GNG12-AS1 to show that this lncRNA has a product related role in MET signaling while its transcription modulates DIRAS3 expression.

Analysis of promoter and enhancer activity and levels of downstream transcripts in liver samples from 15 mammalian species finds an association between the complexity of the regulatory landscape and the evolutionary stability of gene expression.

Although cyclin D1 is frequently overexpressed in human cancers, the full range of its functions in normal development and oncogenesis is unclear. Here, tagged cyclin D1 knock-in mouse strains are developed to allow a search for cyclin D1-binding proteins in different mouse organs using high-throughput mass spectrometry. The results show that, in addition to its established cell cycle roles, cyclin D1 has an in vivo transcriptional function in mouse development.

Pseudogenes are key markers of genome remodelling processes. Here the authors present genome-wide annotation of the pseudogenes in the mouse reference genome and 18 inbred mouse strains, update human pseudogene annotations, and characterise the transcription and evolution of mouse pseudogenes.

Sequence assemblies for the genomes of 16 widely used inbred laboratory mouse strains highlight considerable strain-specific haplotype variation and allow for the identification of regions with the greatest sequence diversity between strains.

The genome of a western lowland gorilla has been sequenced and analysed, completing the genome sequences of all great ape genera, and providing evidence for parallel accelerated evolution in chimpanzee, gorilla and human lineages at a number of loci.

The authors present an integrative framework for identifying structural variants (SVs) in cancer that applies optical mapping, Hi-C, and whole-genome sequencing. They find SVs affecting distal regulatory sequences, DNA replication, and three-dimensional chromatin structure.

High hyperploidy is a common feature in childhood B-cell precursor acute lymphoblastic leukemia. Here, the authors perform proteogenomic and Hi-C analyses of this leukemia and the ETV6/RUNX1 subtype and show that CTCF and cohesin expression are low in hyperdiploid cases and transcriptional dysregulation in relation to topologically associating domain borders in some of these cases.

The genome of the gibbon, a tree-dwelling ape from Asia positioned between Old World monkeys and the great apes, is presented, providing insights into the evolutionary history of gibbon species and their accelerated karyotypes, as well as evidence for selection of genes such as those for forelimb development and connective tissue that may be important for locomotion through trees.

The rate and mechanisms of evolution of transcription factor binding show striking differences across diverse metazoan phyla. This Review highlights insights gained from sequence-based comparisons of genomes and ChIP–seq studies analysing the evolution of transcription factor binding, as well as their conceptual contribution to models of regulatory evolution and gene expression control.

The transcriptional role of c-Myc in maintaining tissue homeostasis is still unclear. Using mice conditionally expressing an activated form of c-Myc in the epidermis, and genome-wide approaches, Frye and colleagues show that c-Myc modulates the expression of the epidermal differentiation complex locus in the skin by displacing or recruiting specific transcriptional regulators. c-Myc activity is negatively regulated in vivo in this context by Sin3a.

Transposable elements can be activated during germ cell maturation, potentially leading to genome instability and rewiring of the genetic circuitry. In this review, the authors discuss how the piRNA machinery suppresses these elements to ensure accurate spermatogenesis.