More than 20 years ago, the human genome was first sequenced. While the first version was full of “holes” representing missing DNA sequences, the genome has been gradually improved in successive rounds. Each has increased the quality of the genome and, in so doing, resolved most of the blank spaces that prevented us from having a complete reading of our genetic material.

The fundamental difficulty researchers faced in reading the genome from end to end is the enormous number of repeated sequences that populate it. The 20,000 or so genes we humans have occupy barely 2% of the entire genome. The remaining 98% is essentially made up of these families of repeated sequences, mobile elements known as transposons and retrotransposons, and—to a lesser but functionally important extent— gene expression regulatory sequences. These function as switches that determine when and where genes are turned on and off.

In March 2022, a major revision of the genome was published in the journal Science. An international consortium of researchers known as “T2T” (telomere to telomere, which are the ends of chromosomes) used a novel strategy based a type of cell (CHM13) that retains only one copy of each chromosome.

Scientists from the University of Rochester have had the naked mole-rat (Heterocephalus glaber) in their crosshairs for some time, previously identifying how their unique cellular aging mechanisms lay the foundation for their long lifespans – up to 41 years, during which the females also remain fertile – and resistance to age-related diseases.

The modification directly led to the improved overall health of the aging mice and an approximate 4.4% increase in median lifespan.

They weigh about an ounce, spend their lives underground in sub-Saharan Africa and are unlikely to be making the shortlist for any cute animal calendars, but the naked mole-rat continues to show scientists it has incredible age-resistant biology beneath its pale, wrinkly skin.

Building on that knowledge, the researchers genetically modified mice to produce the naked mole-rat version of the hyaluronan synthase 2 gene, which makes a protein that produces high molecular weight hyaluronic acid (HMW-HA). While all mammals have hyaluronan synthase 2, the naked mole-rat’s version is somehow enhanced, driving stronger gene expression.

Scientists have found a way to reprogram human cells so that they mimic the highly plastic embryonic stem cells that have so much promise for use in regenerative medicine. By essentially wiping the cell’s “memory”, the team have created so-called induced pluripotent stem (iPS) cells, which could be used to regenerate or repair diseased tissue and organs.

IPS cells are a type of pluripotent cell that can be obtained by reprogramming mature human adult cells (“somatic” cells) into an embryonic stem cell-like state. This means that they have the capacity to differentiate into any cell of the body. They were first demonstrated in 2006, and have myriad potential biomedical and therapeutic uses, including disease modeling, drug screening, and cell-based therapies.

Despite this promise, researchers have continually hit a stumbling block that has prevented iPS cells from realizing their potential. “A persistent problem with the conventional reprograming process is that iPS cells can retain an epigenetic memory of their original somatic state, as well as other epigenetic abnormalities,” Professor Ryan Lister, lead author of a paper presenting the latest breakthrough, said in a statement.