The week’s most astounding developments from the neobiological frontier.

January 6, 2022

It’s not your fault, bro. It’s her neurons.

Two otherwise identical female mice can exhibit remarkably different dispositions when courted by male mice, according to researchers at Caltech, and that difference can be traced to a small set of neurons in the brain. Female virgins are generally gung-ho to mate, and they respond favorably to even the most clumsy fumbling of their “brodent” counterparts. But once female mice give birth and are lactating, they reject even the most suave murine mates and aggressively turn on them with violent attacks. This behavior is controlled by two different neurons in the female brains’ hypothalamus, the scientists showed, which change their responsiveness to social cues during the transition from virginity to maternity. We’re guessing some new human fathers can relate. Neuron

The genetic basis of human fingerprints

Researchers at the Chinese Academy of Sciences, Fudan University, and the University of Edinburgh have uncovered the genetic basis of human fingerprints—identifying specific genes involved in limb development that give our fingertips at birth those characteristic arcs, loops, and whorls that remain unique and unchanged across our lives. Performing a genome-wide association study of 9,909 ethnic Han Chinese individuals and a large-scale meta-analysis of more than 23,000 people of European ancestry, they uncovered dozens of genomic regions associated with fingerprint patterns. Cell

Noncoding DNA connected to schizophrenia and bipolar

Schizophrenia and bipolar disorder are among the most heritable mental health disorders, but we don’t fully understand why. Some genetic factors contributing to both diseases have been identified, but they only account for a small fraction of the total inherited risk. But are we looking in the right places? That’s the question raised by a provocative new study published last month by researchers at the University of Cambridge. There are some 20,000 proteins in the human genome, but their DNA accounts for just 1–2 percent of the total. Searching the remaining “noncoding” 98 percent of genomes taken from 1,340 people—428 of whom have schizophrenia and 188 have bipolar disorder—the researchers uncovered nearly 100 genetic loci (called “novel open reading frames”) that appear to be linked to the two diseases. They say this could help uncover new targets for drug development and disease diagnostics. So maybe it’s not all junk DNA after all. Molecular Psychiatry

Potential new blood test for pre-eclampsia

One of the most common complications of pregnancy is pre-eclampsia, an often serious and somewhat still mysterious condition that presents as high blood pressure and other symptoms in the second half of pregnancy. Even though pre-eclampsia accounts for 15 percent of all premature births in the United States, it remains hard to predict. Now researchers at the biotech company Mirvie in South San Francisco, the University of Pennsylvania in Philadelphia, and Brigham and Women’s Hospital in Boston have analyzed blood to predict pre-eclampsia. Examining RNA in plasma taken from 1,840 racially diverse pregnant women, and stored samples taken from 2,539 women while they were pregnant, they found the plasma RNA levels could predict the complication 75 percent of the time and was seven times more accurate than the current state-of-the-art methods. Nature

Collecting DNA from the air

Traces of DNA in the environment reflect the many local organisms living in that ecosystem, and a team of scientists at York University in Toronto has shown that sampling the air for such DNA could be a game-changing way of monitoring biodiversity and ecological health in terrestrial habitats. They sampled the air within Hamerton Zoological Park in the English countryside district of Huntingdonshire, and they were able to tease out dozens of separate species from the samples, including 17 species found in the zoo as well as DNA from local wildlife, like the endangered Eurasian hedgehog. Though the research focused on animals, we wonder whether the same approach could find traces of people and track human populations in urban and rural settings. Current Biology

Blocking this molecule could block brain inflammation

Scientists at the University of Montreal have discovered a critical role played by an immune system molecule known as DICAM (the domain containing cell adhesion molecule), which experts are now describing as a “molecular passport” for entry into the brain. DICAM contributes to diseases like multiple sclerosis, which is marked by pathogenic inflammation in the brain, by helping a type of pro-inflammatory immune cell cross the blood–brain barrier. Blocking DICAM with antibodies in mice prevented the infiltration of those immune cells, reduced the severity of an inflammatory condition known as encephalomyelitis, and suggested targeting DICAM therapeutically could reduce inflammation in the brain. Science Translational Medicine

Electric fields control critical “chirality” of molecules

Many molecules found in nature exist in two separate but chemically equal forms that are nevertheless geometrical opposites and not identical—in the same way your right and left hands are mirror images of one another. This basic property of matter, which chemists call “chirality,” is hugely important in medicine because some drugs are active in one form and toxic in the other. Controlling chirality is also seen as enabling for future data storage devices because introducing it could enhance the storage capacity of future chips. There are many ways to chemically control chirality, but now researchers at the University of California, Berkeley have developed a way to do it physically, showing that they could reversibly control the handedness of materials with an electric field, paving the way for controlling chirality electronically. Science Advances