GEN • September 2023 • Sticky Ends

chologists, engineers, and security professionals alike have found it useful to tinguish between “known unknowns” and “unknown unknowns.” And molecular b ologists? Besides investigating known omes, they are looking into an unknown ome—specifically, an understudied portion of the proteome they call the nknome.” It consists of proteins that are encoded by genes in the human genome, t whose functions are still mostly unknown. As indicated in PLOS Biology, scientists the MRC Laboratory of Molecular Biology have developed an unknome database t ranks proteins based on how little is known about them. The scientists also ed that in an animal model, knocking down genes encoding “low knownness” s could compromise survival. “Our work,” the scientists wrote, “highlights a need ure that misannotation does not erode our awareness of our own ignorance.”

Surprising Gene Absences in Mind Control Worms

The fungus that inspired the TV show The Last of Us isn’t the only parasite that exerts “mind control.” There are, for example, hairworms that cause their hosts, arthropods such as crickets and grasshoppers, to seek water. The hosts drown, and the hairworms leave their victims and seek out mates, ensuring that the hairworm lifecycle continues. In a recent study by Field Museum scientists, two hairworm species had their genomes sequenced. Surprisingly, the genomes lacked genes that occur in nearly all other animals. This result was reported in Current Biology, along with the observation that the genes are associated with cilia organization. It is unclear how the lack of cilia affects the hairworms. But it is thought that if certain structures in a parasite become unnecessary because the parasite can rely on its host, those structures may be lost.

Ecological Risks Posed by Time-Traveling Pathogens

Within a frozen wasteland, a strange organism lies dormant. Eons pass. Then, finally, a thaw occurs, and the organism awakens. What havoc might it wreak? This may sound like a science fiction scenario. Well, it is. But it also describes what is happening right now as climate change progresses, glaciers and permafrost melt, and ancient microorganisms once trapped in ice escape. To assess the risks posed by these microorganisms, scientists based at the European Commission ran artificial evolution experiments in silico. The results, which appeared in PLOS Computational Biology, suggest that “time-traveling pathogens” could, in a few highly unpredictable cases, precipitate substantial changes in ecosystem richness, potentially threatening human health. The scientists emphasized that given the sheer abundance of ancient microorganisms released into modern communities, even a low probability of outbreak events is worrying.