genomics

A team of researchers has analyzed more than 300 human genomes from the last 50,000 years and has concluded that most of the gene flow we received from Neanderthals is attributable to a single period, which probably occurred between 50,500 and 43,500 years ago. In addition, Neanderthal inheritance underwent rapid natural selection in subsequent generations, especially on the X chromosome, according to a study published in Science.

A team of researchers at the Centre for Genomic Regulation in Barcelona (CRG) has found that a region of the genome is less active in model mice and people with Down's syndrome. This region is found in the so-called dark genome and does not code for a protein. According to the authors of the study, this "leads to reduced neurogenesis and impaired plasticity, which play a direct role in learning and memory". The results are published in the journal Molecular Psychiatry.

A team of researchers led by the Max Planck Institute for Evolutionary Anthropology in Germany has analysed nearly 10,000 ancient genomes and found six cases of people with Down's syndrome and one with Edwards' syndrome. Most of them died before or shortly after birth. The findings correspond to different periods up to 5,500 years old and several of them have been found in Navarra. According to the authors, "the care with which the burials were carried out and the objects found with these individuals indicate that ancient societies probably treated people with trisomies 18 and 21 as members of their communities". The findings are published in Nature Communications.

A Chinese research team has reported the birth of a crab-eating macaque that is a chimera: an animal generated from the mixing of embryonic cells from two different individuals; in this case, from the same species, according to the journal Cell. Until now, this type of chimera had only been developed with rodents. This is the first time it has been achieved in non-human primates.

A team of researchers has managed to combine more than seven synthetic chromosomes made in the laboratory in a single yeast cell. This involves developing for the first time a eukaryotic cell with more than 50% synthetic DNA, which survives and replicates in a similar way to wild yeast strains. The results, which are part of the Synthetic Yeast Genome Project (Sc2.0), are published in the journal Cell.

A US research team has identified several genes that may be associated with a strict vegetarian diet. Some of these genes have "important roles in lipid metabolism and brain function", according to the paper, which suggests that these differences could explain the ability to subsist on a vegetarian diet in those who carry these genes. The study, published in the journal PLoS ONE, used data from the UK Biobank to compare a group of more than 5,000 vegetarians with a group of more than 320,000 non-vegetarians.

A team of scientists led by the Catholic University of America in Washington has designed new artificial vectors based on viruses to improve gene therapy processes. The main novelty is that they are constructed from viruses that infect bacteria. Among other advantages, this would make it possible to avoid the possible memory of our defences against them and have a greater capacity. According to the authors, who publish their results in the journal Nature Communications, these nanoparticles "have the potential to transform gene therapies and personalised medicine".

In a series of three articles and a companion article - collected in Nature Biotechonology - Nature publishes the first draft of the human pangenome reference, which contains highly detailed data from 47 genetically diverse individuals. The first human genome was published more than two decades ago but, being from a single person, it does not represent human diversity, whereas the pangenome refers to the gene pool of our entire species. The ultimate goal of the Human Pangenome Reference Consortium project is to include genetic material from 350 people by 2024. It is hoped that this data will allow more clinically relevant genetic variants to be identified.

A study led by Spanish researchers and published in Science Advances has tested a new technique to improve gene therapy treatments for Parkinson's disease. Using ultrasound, they have managed to open the blood-brain barrier in specific areas, allowing the viruses used in the therapy to pass through and better reach the desired brain areas. After testing it on monkeys and three patients -patients were not given gene therapy, but the efficacy of the technique was tested using a radiotracer that does not normally cross the blood-brain barrier-, their conclusions are that the technique is safe and feasible and "could allow early and frequent interventions to treat neurodegenerative diseases".

Seven studies published in Nature and Nature Medicine look at how lung cancer evolves, with genomic studies of more than 1,600 tumour samples taken from 421 patients in the TRACERx project. The research includes the most common type of lung cancer (NSCLC) and assesses why tumours sometimes recur, spread to other parts of the body or the effects of platinum-based chemotherapy.