Reviews & Analysis

At each ovulation cycle, the single-layer epithelia that encapsulate mammalian ovaries undergo rupture and rapid repair. Recent studies have identified stem cell pools that ensure ovarian epithelial homeostasis, thus providing insights into the regulation of stem cell function and the contribution of stem cells to ovarian tumorigenesis.

The unique physical and chemical properties of microfluidic devices have underpinned notable recent advances in molecular cell biology research and will facilitate a new era of biological enquiry of increased precision.

DNA methylation and H3K9 methylation are typically associated with gene silencing. Genetic, genomic, structural and biochemical data reveal functional connections between these two epigenetic marks. They also highlight how specialized protein domains that recognize the marks are essential for their establishment and maintenance at appropriate genomic loci.

Pseudouridine is the most abundant internal post-transcriptional modification of spliceosomal small nuclear RNAs and ribosomal RNAs. Transcriptome-wide maps of RNA pseudouridylation have recently established that pseudouridines are also found in mRNAs, potentially representing a new mechanism of proteomic diversification.

Measurement of protein binding to a large number of RNA variants reveals binding patterns and helps to quantify binding specificities, which enables the development of RNA–protein interaction models. Such models are changing the binary view of RNA binding by proteins as either specific or nonspecific.

The recent discovery of the genes encoding components of the mitochondrial calcium uniporter paves the way for further study of its mechanism of action and its relevance to physiological and pathological processes.

Aneuploidy, which results from chromosome mis-segregation, is a hallmark of cancer, but it can also inhibit tumorigenesis. Recent studies on the short- and long-term consequences of aneuploidy, which are caused by gene-specific effects and a stereotypic aneuploidy stress response, provide insights into this contradictory role in tumorigenesis.

Repressive histone Lys methyltransferases (KMTs) mediate gene silencing by methylating histone H3 Lys 9 (H3K9), H3K27 and H4K20. Progress has been made in our understanding of the biochemical and functional properties of KMTs, the mechanisms of their recruitment to chromatin and the interplay between them.

Autophagy serves to degrade proteins during starvation. Recent progress has illuminated how, during starvation and nutrient repletion, autophagy can mobilize diverse cellular energy and nutrient stores, such as lipids, carbohydrates and iron, to salvage key metabolites that sustain and facilitate core anabolic functions.

Recent findings revealed that DNA–protein crosslinks (DPCs) in yeast and Xenopus laevis are repaired by a dedicated, protease-based DNA-repair pathway. Mutations in the putative human homologue of a DPC protease result in premature ageing and cancer predisposition.

Actomyosin-mediated contractility generates mechanical stress in animal cells and underlies muscle contraction, cell migration, cell division and tissue morphogenesis. Insight into the mechanics of actomyosin arrays that lack sarcomeric organization has revealed novel modes of force transmission and shown that diverse mechanical behaviours can arise from common molecular components.

The function of p53 as a tumour suppressor has been attributed to its ability to promote cell death or permanently inhibit cell proliferation. However, p53 can also contribute to cell survival by regulating various metabolic pathways to allow cells to adapt to mild metabolic stresses.

Recent studies in different species have increased our understanding of the factors and molecular mechanisms that underlie the specification of germ cells, which are the specialized cells that generate gametes. Moreover, studies are elucidating how these cells ensure that only germline-appropriate transcripts are translated to protect germ cell identity.

Recent studies have shown that nuclear export of mRNAs, which is a crucial step in the regulation of gene expression, can be selective in mammalian cells. Selective transport involves transcription-export complexes TREX and TREX-2 and controls biological processes such as DNA repair, haematopoiesis, proliferation and maintenance of pluripotency.

DNA assembly methods are essential to the field of synthetic biology. Casiniet al. discuss the powerful DNA assembly methods and standards developed in the past decade that facilitate the streamlined assembly of genetic networks and even of whole chromosomes and cells.

Recent studies have revealed that the RNase III enzymes Drosha and Dicer (including newly discovered Dicer isoforms) have non-canonical nuclear RNAi functions in various organisms. These include the regulation of transcription initiation and termination, and the processing of various RNA species.

During the G1–S phase transition of the cell cycle, a variable subset of previously 'licensed' origins of replication is activated to initiate DNA synthesis. Insight is being gained into the mechanisms underlying which origins are activated and when; these mechanisms are associated with nuclear organization, cell differentiation and replication stress.

The mitochondrial respiratory chain comprises large multi-subunit protein complexes that generate ATP. The crystal structure of the entire bacterial complex I was recently solved, providing novel insights into its core architecture, as well as the electron transfer and proton translocation pathways and the coupling between them.

Apoptosis, autophagy and necroptosis are discussed in the context of molecular mechanisms of programmed cell death during development and tissue homeostasis. The signals that dying cells produce can in turn induce the apoptosis or proliferation of neighbouring cells.

Mitochondrial proteases can be classified into subgroups depending on their function and location. They are highly specific and modulate biochemical activities that are essential for mitochondrial function and integrity. Impaired or dysregulated function of mitoproteases is associated with ageing and longevity, as well as with pathological conditions and human hereditary diseases.