National Biotechnology Centre (CNB-CSIC)

A team from the Netherlands has successfully edited pathogenic mutations in mitochondrial DNA in human cells, changes in DNA that cause disease, according to research published in PLoS Biology. The authors used a genetic tool known as a base editor. Until now, techniques derived from CRISPR have made it possible to correct mutations in nuclear DNA, and new techniques are being developed that allow mitochondrial DNA to be edited.

Several studies have suggested that taurine concentrations in the blood decrease with age and that supplementation with this amino acid could delay ageing. Now, a study carried out in the USA with Spanish participation, including data from humans, monkeys and mice, shows that this decline is not systematic and that it depends more on individual factors than on ageing, so taurine is not a reliable marker of ageing. The results are published in the journal Science.

A team from the Children's Hospital of Philadelphia and Penn Medicine (United States) has successfully treated a baby diagnosed with a rare genetic disorder using personalised CRISPR gene editing therapy. The baby, known only by the initials KJ, was born with a rare metabolic disease known as severe carbamoyl phosphate synthetase 1 (CPS1) deficiency. After spending the first months of his life in hospital on a very restrictive diet, KJ received the first dose of his tailored therapy in February 2025, between six and seven months of age. The treatment, which is being used for the first time for this type of disorder, was administered safely, and the baby is now growing well and improving. The case is detailed in a study published by The New England Journal of Medicine (NEJM).

23% of people infected with SARS-CoV-2 between 2021 and 2023 developed long covid and more than half of them had persistent symptoms for two years. These are the main conclusions of a study led by ISGlobal that followed more than 2,700 people in Catalonia. The results are published in the journal BMC Medicine.

Colossal Biosciences has announced the creation of genetically modified mice with characteristics reminiscent of the fur of extinct mammoths, such as fur colour, texture and thickness. The non-peer-reviewed results were shared today in the BioRXiv prepublication repository.

Research has analyzed how extreme heat influences the biological age of elderly populations, specifically in the United States. The study, published in Science Advances, used blood samples from more than 3,600 adults with an average age of 68 collected between 2010 and 2016. The team compared epigenetic aging trends with the number of days of extreme heat in the participants' places of residence. The models showed that more days of heat or long-term heat — over a period of one to six years — increased the biological age of the participants by more than two years.

An international team has analyzed data from nearly half a million people to analyze the influence of genes or environment on mortality, age-related diseases and aging. Although the relationship may vary according to the type of disease, their conclusions are that the environment -especially socioeconomic conditions, smoking habits and physical exercise- has a much greater influence than genetics in all the aspects studied. Among other data, environment explains 17 % of the variation in mortality risk, while genetics is limited to 2 %. The results are published in the journal Nature Medicine. 

A team of researchers has used embryonic stem cell engineering to create a bipaternal mouse - a mouse with two male parents - that lived to adulthood. Their results, published in the journal Cell Stem Cell, show how targeting a particular set of genes involved in reproduction enabled this breakthrough in unisexual reproduction in mammals.

Thirty eight scientists from different specialties, including Craig Venter, a pioneer in the creation of artificial synthetic life, have written an article in the journal Science in which they assess the possibilities of synthesizing mirror organisms, but also warn of the risks they pose. This type of microorganisms, which would present a mirror structure to that currently found in nature, would have potential applications due to their resistance to biological degradation. However, they would also pose a danger because they would not be recognized by our defenses and could spread in ecosystems. Scientists call for more research and a broad debate, and warn that until more is known, this type of organism should not be created. 

Two articles published in Nature describe a new genome editing technique that enables the insertion, inversion, or deletion of long DNA sequences at specific positions in the genome. This is a one-step approach that could offer a simpler method for genome editing in the future. The authors describe a technique to create reprogrammable recombinases—key enzymes in genetic recombination. These enzymes are guided by RNA, which acts as a bridge, directing the recombinase to target sites and facilitating predetermined editing.