Molecular biology

Life could use a more expansive genetic code in theory, but new work shows that improving on three-letter codons would be a challenge.

Steven Strogatz explores the mysteries of knots with the mathematicians Colin Adams and Lisa Piccirillo.

Large blocks of genes conserved through hundreds of millions of years of evolution hint at how the first animal chromosomes came to be.

The detailed understanding of brains and multicellular bodies reached new heights this year, while the genomes of the COVID-19 virus and various organisms yielded more surprises.

Genomes hold immense quantities of noncoding DNA. Some of it is essential for life, some seems useless, and some has its own agenda.

The DNA of some viruses doesn’t use the same four nucleotide bases found in all other life. New work shows how this exception is possible and hints that it could be more common than we think.

Researchers have finally seen how some smell receptors bind to odor molecules. The work yields new insights into one of the most mysterious and versatile senses.

In some symbiotic partnerships, an RNA-based mechanism may sabotage the growth of greedy hosts.

Transcription factors that act throughout the genome can arise from mashups of transposable elements inserted into established genes.