Review Articles in 2021

In this Review the authors provide an overview of key algorithmic developments, popular tools and emerging technologies used in the bioinformatic analysis of genomes. They also describe how such analysis can identify point mutations, copy number alterations, structural variations and mutational signatures in cancer genomes.

The authors review the field of mammalian mitochondrial genome engineering, culminating in the recent development of mitochondrially targeted programmable nucleases and base editors. They describe research that led to the development of animal models of mitochondrial disease, as well as the potential for translating these approaches to the clinic.

Loci that encode long non-coding RNAs (lncRNAs) can be complex and function through multiple modalities. The authors provide a framework for elucidating the physiological roles of lncRNAs using genetically engineered mouse models, including whole-gene deletion, transcription termination, reporters and transgene rescue strategies.

Machine learning is widely applied in various fields of genomics and systems biology. In this Review, the authors describe how responsible application of machine learning requires an understanding of several common pitfalls that users should be aware of (and mitigate) to avoid unreliable results.

In this Review, the authors discuss explanations for why ultraconserved sequences — which are presumed to be functionally crucial on the basis of strong evolutionary constraint — often result in surprisingly minor phenotypic consequences when experimentally disrupted. They also discuss the wider implications of extreme non-coding conservation for understanding the mechanisms of gene regulation and human variant interpretation.

Hologenomic studies aim to further our understanding of host–microbiota interactions through the integrated analysis of host genomes and microbiota metagenomes. Here, Alberdi and colleagues discuss key considerations for designing optimal hologenomic studies and outline important biological questions that these studies can address.

The authors review overlapping sequences as fundamental features of prokaryotic, eukaryotic and viral genomes, discussing the diverse topologies and functions of overlapping genes, open reading frames and coding sequences. Moreover, they highlight the potential of harnessing sequence overlaps for synthetic biology approaches.

In this Review, Janssen and Lorincz discuss the intricate and multilayered interplay between chromatin marks. Focusing on histone methylation and DNA methylation during mammalian development, they discuss the implications for gene regulation, differentiation and human disease.

In this Review, Zhang et al. summarize our current understanding of the molecular mechanisms underlying the responses of plants to abiotic stresses, and how this knowledge can be used to improve crop resilience through genetic, chemical and microbial approaches.

In this Review, Loos and Yeo summarize our current understanding of the genetic underpinnings of monogenic and polygenic obesity. They highlight the commonalities revealed by recent studies and discuss the implications for treatment and prediction of obesity risk.

In this Review, Przybyla and Gilbert describe the latest approaches for CRISPR-based functional genomics screens, including the adoption of single-cell transcriptomic read-outs and applications in characterizing the non-coding genome and mapping genetic interactions at scale.

In this Review, Conine and Rando discuss, across species, the myriad examples of intercellular RNA trafficking from nurse cells or somatic tissues to developing gametes, and consider how intercellular RNA trafficking shapes the germline epigenome.

In this Review, the authors describe our latest understanding of the emergence and properties of SARS-CoV-2 genetic variants, particularly those designated as WHO (World Health Organization) ‘variants of concern’. They focus on the consequences of these variants for antibody-mediated virus neutralization, with important implications for reinfection risk and for vaccine effectiveness.

The authors review intra-individual and inter-individual plant epigenome variation during development and in response to environmental changes, including stress. They also discuss functions of epigenome plasticity and epigenome editing technologies that will drive future research.

Regular physical activity reduces the risk of chronic disease and mortality, but the mechanisms underpinning this protective effect are poorly understood. Here, Kim et al. review candidate genes and pathways implicated in human performance by genetic, genomic and multi-omic studies.

Leigh and colleagues describe the potential of the emerging field of macrogenetics to improve conservation and biodiversity management. Challenges preventing the field from reaching its full promise are highlighted and possible solutions and a framework for future macrogenetic studies are proposed.

The evolutionary persistence of animal symbioses depends on both host and symbiont innovations. Perreau and Moran review how genome sequencing and related experiments have clarified how these innovations arise under different symbiont population structures, categorized here as open, closed and mixed.

In this Review, Ethan Bier discusses how several impactful technical advancements, particularly involving CRISPR-based methods, are providing a diverse toolkit of gene-drive systems for the control of populations such as insect vectors of disease.

In this Review, Senft and Macfarlan discuss the diverse ways by which transposable elements (TEs) contribute to mammalian development and evolution, including direct contributions through TE-derived regulatory elements, RNAs and proteins, as well as indirect effects through the evolution of a TE repression system, the Krüppel-associated box zinc finger proteins (KRAB-ZFPs).

In this Review, the authors discuss computational methods for interpreting the molecular and clinical effects of genetic variants. They focus on methods leveraging machine learning, including those that characterize the effects on wider molecular networks.