In this week's Science, an international team of researchers describes the whole-genome sequencing of mountain gorillas, revealing how the animals' shrinking population has led to inbreeding that is affecting their survival. The team sequenced blood samples collected from 13 eastern gorillas and compared their genomes of these animals with those of all four gorilla subspecies. They discovered that genetic diversity is much lower in the eastern subspecies, particularly for genes important to immune system function, and concluded that the mountain gorilla is at least partially genetically isolated from the other eastern gorilla subspecies and possesses extremely low genetic variation that may reflect inbreeding. GenomeWeb has more on this study here.
Also in Science, researchers from Stanford University report on the identification of a genetic mutation associated with maternal aneuploidy, or the inheritance of an irregular number of chromosomes from one's mother and a key cause of miscarriage, and suggest that this mutation might be more common than previously believed. The researchers sequenced the genomes of day-three embryos in which aneuploidy had been detected, as well as their parents during in vitro fertilization cycles, and identified a particular region of the genome that appears to be associated with defects in maternal chromosome number. The region harbors a gene called polo-like kinase 4, which the team tested, discovering a specific mutation that increases the rate of maternal aneuploidy. Further screening showed that this variant is common in many modern human populations and that it has probably undergone recent positive selection.