08 December 2010
Vol 2, Issue 61

About The Cover

Cover image expansion

ONLINE COVER Scanning Fetal DNA. During pregnancy, a fetus releases its DNA as short fragments into the blood of its mother. In this issue, Lo et al. report that by sequencing billions of DNA molecules from the plasma of a pregnant woman they were able to assemble the full genome of the fetus prenatally and noninvasively and identify a mutation in the fetal DNA for the inherited blood disease β-thalassemia. The outermost ring of this week’s cover image depicts human chromosomes arranged in a circle. The green, red, and blue rings show the sequence composition (GC content) and the extent of sequencing for total (mainly maternally-derived) DNA and fetal-specific DNA in maternal plasma, respectively. [CREDIT: PHOTOGRAPH OF FETUS/SCIENCE PHOTO LIBRARY; SCHEMATIC ADAPTED FROM FIGURE 2B IN LO ET AL. BY ALLEN CHAN AND LEONG WOO YAN]