The newly completed genome, dubbed T2T-CHM13, represents a major upgrade from the current reference genome, called GRCh38, which is used by doctors when searching for mutations linked to disease, as well as by scientists looking at the evolution of human genetic variation. Among other things, the new DNA sequences reveal never-before-seen detail about the region around the centromere, which is where chromosomes are grabbed and pulled apart when cells divide, ensuring that each “daughter” cell inherits the correct number of chromosomes.
A group of geneticists from Berkeley Lab, UC Davis, UC Santa Cruz, and UC Berkeley are unraveling new details about human evolution by studying the uniquely regulated portion of our chromosomes that surround the centromeres. These stretches of DNA – termed centromere-proximal regions (CPRs) – are largely composed of highly repetitive, mostly non-gene-coding sequences that … Read more »
In a study published in eLife, Biological Systems and Engineering (BSE) postdoctoral researcher Grace Lee and senior scientist Gary Karpen investigated the extent to which transposons—bits of DNA that copy themselves and jump to other locations in the genome—harm organisms through epigenetic means, such as changing the way DNA is packaged in cells, and whether this influences how transposons evolve. In a Q&A with the journal, Lee explained the background of the research, the specific question she and Karpen were interested in, and the most illuminating result among their findings.
In a paper published June 21 in the journal Nature, Berkeley Lab Biological Systems and Engineering Division researchers Amy Strom and Gary Karpen provide evidence that liquid-liquid phase separation in the nucleus of cells plays an important role in how genes are regulated to be silenced or expressed. They observed that heterochromatin—an unusual part of DNA that generally must be silenced for cells to function properly—is sequestered in droplets that fuse together just like two drops of oil surrounded by water. Understanding this mechanism could open up a third of the genome that was previously inaccessible to genome manipulation and gene therapy, Karpen said. Read more in the News Center release.
A new study, led by Gary Karpen of the Biological Systems & Engineering (BSE) Division, links the overexpression of 14 genes related to cell division to cancer patients’ prognosis and response to specific treatments. The researchers said the findings, published today in the journal Nature Communications, could lead to a new biomarker for the early stages of tumor development. The information obtained could help reduce the use of cancer treatments that have a low probability of helping.
The research team included lead author Weiguo Zhang and Jian-Hua Mao of BSE; collaborators Wei zhu and Anshu Jain; and Ke Liu and James (Ben) Brown of the Environmental Genomics & Systems Biology Division. Read more on the Berkeley Lab News Center.