Capturing a hard-wired variability: What makes some identical twins noticeably different?
"We have captured a fundamental randomness at the level of gene expression that has never before been described — one that persists throughout development and into adulthood," says Ludwig scientist Rickard Sandberg at the Karolinska Institutet in Sweden. The discovery was made possible by a powerful new technique developed by Sandberg’s lab for analyzing the global expression of genes in single cells. With the exception of a subset of genes found on sex chromosomes, every mammal inherits one copy of every gene from each of its parents. Each of those copies is known as an allele, and alleles often differ measurably from their genomic siblings — a fact that accounts for a good deal of human and animal diversity…