In this Review, Li and Durbin discuss how to generate telomere-to-telomere assemblies for large haploid or diploid genomes using currently available data types and algorithms, and outline remaining challenges in resolving highly repetitive sequences and polyploid genomes.

In this Review, the authors summarize our current understanding of nuclear pre-mRNA and mRNA decay pathways. They describe how aberrantly processed mRNAs are targeted for decay in the nucleus and how this process is regulated to finely control gene expression.

In this Perspective, Werner and colleagues discuss the many potential mechanisms by which natural antisense transcripts (NATs) can regulate expression of their complementary sense transcripts, the biological implications of their regulatory effects and the potential of NATs for therapeutic applications.

Genetic variants acquired early during embryogenesis can affect numerous tissues. The authors review the phenomenon of embryonic mosaicism, with a focus on small variants, and discuss mechanisms of cell competition that allow mosaic clones to expand, as well as the functional consequences of mosaicism for embryo viability and the health of the organism.