Enlarge (credit: Timothy Hearsum)

Fritz Haber: good guy or bad guy? He won the Nobel Prize in Chemistry in 1918 for his part in developing the Haber-Bosch process, a method for generating ammonia using the nitrogen gas in air. The technique freed agriculture from the constraint of needing to source guano or manure for nitrogen fertilizer and is widely credited for saving millions from starvation. About half of the world’s current food supply relies on fertilizers made using it, and about half of the nitrogen atoms in our bodies can be traced back to it.

But it also allowed farmers to use this newly abundant synthetic nitrogen fertilizer with abandon. This has accentuated agriculture’s role as a significant contributor to global warming because the emissions that result from these fertilizers is a greenhouse gas—one that has a warming potential almost 300 times greater than that of carbon dioxide and remains in the atmosphere for 100 years. Microbes in soil convert nitrogen fertilizer into nitrous oxide, and the more nitrogen fertilizer they have to work with, the more nitrous oxide they make.

Agriculture also leaks plenty of the excess nitrogen into waterways in the form of nitrate, generating algal blooms that create low-oxygen ‘dead zones’ where no marine life can live.

Enlarge / The spliceosome is a large complex of proteins and RNAs. (credit: NCBI)

Almost 1,500 genes have been implicated in intellectual disabilities; yet for most people with such disabilities, genetic causes remain unknown. Perhaps this is in part because geneticists have been focusing on the wrong stretches of DNA when they go searching. To rectify this, Ernest Turro—a biostatistician who focuses on genetics, genomics, and molecular diagnostics—used whole genome sequencing data from the 100,000 Genomes Project to search for areas associated with intellectual disabilities.

His lab found a genetic association that is the most common one yet to be associated with neurodevelopmental abnormality. And the gene they identified doesn’t even make a protein.

Trouble with the spliceosome

Most genes include instructions for how to make proteins. That’s true. And yet human genes are not arranged linearly—or rather, they are arranged linearly, but not contiguously. A gene containing the instructions for which amino acids to string together to make a particular protein—hemoglobin, insulin, serotonin, albumin, estrogen, whatever protein you like—is modular. It contains part of the amino acid sequence, then it has a chunk of DNA that is largely irrelevant to that sequence, then a bit more of the protein’s sequence, then another chunk of random DNA, back and forth until the end of the protein. It’s as if each of these prose paragraphs were separated by a string of unrelated letters (but not a meaningful paragraph from a different article).

Enlarge (credit: YelenaYemchuk)

Commercialization has not dealt kindly with the Mayan Food of the Gods. Modern chocolate products are filled with sugar and calories, contributing to the obesity epidemic in the West. And the cocoa crop is hardly in great shape; climate change is decreasing production, causing prices to rise; farmers in West Africa have responded by clear-cutting rainforests to plant more cocoa plants. However, researchers at ETH Zurich may have found a path to start addressing both problems, making chocolate that has less sugar and calories and makes more efficient use of the cocoa crop. The Swiss perfected chocolate-making over 200 years ago, so if they say the chocolate is good, it is.

Chocolate is traditionally made by mixing dried, roasted, and ground fermented cocoa beans to make cocoa mass. The cocoa mass is then mixed with refined sugar, usually from sugar beets. Instead of sugar, this new Swiss whole fruit chocolate uses the pulp surrounding the cocoa beans along with the inner rind of the cocoa pod husk to make a cocoa gel. When mixed with cocoa mass, this produces chocolate that is higher in fiber and lower in saturated fat than conventional chocolate.

The “whole fruit” on its label is certainly more appealing than the air or fish oil that has previously been substituted for cocoa butter to reduce the saturated fat content of chocolate confections. (Extra cocoa butter, or fat isolated from the cocoa bean, is sometimes added to cocoa mass to make the end product smoother and waxier.) The pulp and the cocoa pods are generally discarded, so upcycling them instead of tossing them could reduce the land use impact and global warming potential of cocoa cultivation.

Enlarge / The Colorado River toad, also known as the Sonoran Desert Toad. (credit: Mark Newman)

It is becoming increasingly accepted that classic psychedelics like LSD, psilocybin, ayahuasca, and mescaline can act as antidepressants and anti-anxiety treatments in addition to causing hallucinations. They act by binding to a serotonin receptor. But there are 14 known types of serotonin receptors, and most of the research into these compounds has focused on only one of them—the one these molecules like, called 5-HT2A. (5-HT, short for 5-hydroxytryptamine, is the chemical name for serotonin.)

The Colorado River toad (Incilius alvarius), also known as the Sonoran Desert toad, secretes a psychedelic compound that likes to bind to a different serotonin receptor subtype called 5-HT1A. And that difference may be the key to developing an entirely distinct class of antidepressants.

Uncovering novel biology

Like other psychedelics, the one the toad produces decreases depression and anxiety and induces meaningful and spiritually significant experiences. It has been used clinically to treat vets with post-traumatic stress disorder and is being developed as a treatment for other neurological disorders and drug abuse. 5-HT1A is a validated therapeutic target, as approved drugs, including the antidepressant Viibryd and the anti-anxiety med Buspar, bind to it. But little is known about how psychedelics engage with this receptor and which effects it mediates, so Daniel Wacker’s lab decided to look into it.