Genes & Cells

Heritable sleep
Morning larks can thank their parents for their early waking habit. The team captured physical activity using monitors worn on the hip and used sleep diaries to learn the sleep habits of 723 Old Order Amish in Lancaster County, Penn. This insular population lives free from many sleep-confounding technological gadgets. On average, men work up at 4:59 a.m., while women slept in until about 5:14 a.m. Whether a subject rose early or late depended heavily on the waking habits of his or her relatives, researchers from the University of California, San Francisco and colleagues report in an upcoming Sleep. —Laura Sanders

Gene screens find incest
Genetic tests used to diagnose children with disabilities can also turn up evidence of incest. Assays designed to look for mutations also spot genome regions that contain far too little diversity, a sign that the parents are first-degree relatives. Several such cases have been identified already, scientists from Baylor College of Medicine in Houston report in the Feb. 12 Lancet. Finding incest can aid diagnosis and treatment of inherited disorders, since incest can lead to disabilities. But the information also raises thorny ethical issues, such as whether to report potential criminal conduct or to inform parents about what could be revealed before testing a child. —Laura Sanders

Flu changes
Some flu mutations go hand-in-hand, a new study finds. The results, appearing February 17 in PLoS Genetics, may help scientists predict what the next season’s flu will look like, enabling more effective vaccines. Researchers at the University of Pennsylvania in Philadelphia and colleagues scrutinized genetic changes for 40 years of different flu strains. Some of these mutations worked as a team, so that seeing one mutation increased the likelihood of the other one showing up in the next few years. The new technique was able to pick out several well-known mutations that confer Tamiflu resistance. The method may help researchers create consistently effective flu vaccines. —Laura Sanders

Gonorrhea got human DNA
Gonorrhea bacteria borrowed a piece of human DNA, researchers have discovered. Bacteria swap genetic material regularly, but it is rare for microbes to pick up DNA from their hosts. Seven of 62 strains of Neisseria gonorrhoeae studied contained a piece of human DNA known as an L1 element, a team at Northwestern University in Chicago reports online February 14 in the online journal mBio. Closely related species of Neisseria, including one that causes meningitis, do not have the human DNA, leading the researchers to speculate that gonorrhea bacteria picked up the L1 fragment relatively recently in evolutionary history. —Tina Hesman Saey

Developmental difference
Mice are early bloomers, a study of the early development of mice and cattle reveals. Mice make the decision about which cells in the early embryo will form the placenta far earlier than cattle do, Debra Berg and colleagues at the AgResearch Crown Research Institute in Hamilton, New Zealand, report in the Feb. 15 Developmental Cell. Humans, pigs, rabbits and other mammals may follow the cattle’s timeline more closely than the mouse developmental clock, suggesting that cattle might be better animals to study than mice to understand the earliest stages of human development. —Tina Hesman Saey