In a new study published in Cell, Stanford University's Stephen Quake and his colleagues report the first genetic comparison of single sperm cells, says New Scientist's Jessica Hamzelou. Using a high-throughput single-cell whole-genome analysis method, the team compared sperm cells from a single sample. To overcome the difficulty inherent in analyzing individual cells, they used a microfluidic chip that is about three square centimeters, Hamzelou says. "The group injected a liquid sample containing sperm cells from the ejaculate of one man into the channels of their chip," she adds. "Valves were set up to separate 91 sperm cells into individual chambers. The team was then able to amplify the genes in each cell in preparation for sequencing."
The researchers scanned each of the 91 sperm cells to measure recombination in the DNA and found that some of the cells had recombined in unexpected places. "The findings suggest that the process of genetic reshuffling is unique to each sperm cell. This further adds to the genetic diversity between siblings," Hamzelou says. The experiment also has implications for how recombination problems causing male fertility could be diagnosed, and could be used to help select eggs for in vitro fertilization, the researchers say. Albert Einstein College of Medicine's Adam Auton, who was not involved in the study, tells Hamzelou that the technique used by Quake's team could also be used to study individual cancer cells, to get a better picture of which genes are mutated.
Daily Scan's sister publication, GenomeWeb Daily News, has more on the study here.