Editor's Note: Some of the articles described below are not yet available at the PNAS site, but they are scheduled to be posted some time this week.
A team from Yale University and the National Institute of Allergy and Infectious Diseases takes a look at transcripts in individual Trypanosoma brucei cell parasites from tsetse fly salivary glands. Using single-cell RNA sequencing on a pool of more than 2,000 isolates from tsetse flies, the researchers found gene expression-based clusters of developmentally similar T. brucei cells, along with a cell surface protein that showed potential as a vaccination target in mice. "We describe proteins associated with the different parasite developmental stages in salivary glands and specifically highlight a family of non-variant surface proteins associated with [infectious] metacyclic parasites," they write. "Immunization with one member of this family reduced parasitemia early in the infection in mice, promising to be a potential candidate antigen for a transmission blocking vaccine approach."
Researchers in Israel, the UK, and Switzerland estimate the number of individuals carrying variants involved in inherited retinal disease risk around the world. After putting together a database of almost 277,000 variants spanning 187 genes implicated in autosomal recessive inherited retinal diseases from half a dozen global populations, the team focused in on 10,044 variants classified as causative for one or more of these heterogeneous eye conditions. From there, the authors used an algorithm to estimate the number of individuals with autosomal recessive inherited retinal diseases around the world — around 5.5 million people — and to take a crack at tallying the number of unaffected carriers, which appeared to include billions of people around the world.
A research from a group in the US and Russia explores human gut microbial community development, by first culturing and genetically characterizing bacteria in healthy infant poop over time. With this approach, the researchers found sets of bugs that predominated earlier or later in the infant gut in the six months after birth. They then used those strains to model gut colonization, bacteria fitness, and more in germ-free mice receiving infant formula. "Applying feature-reduction methods disclosed a set of metabolic pathways whose presence and/or expression correlates with strain fitness and that enable early-stage colonizers to survive during introduction of later colonizers," they report, adding their broader research strategy "can be used to test the magnitude of the contribution of identified metabolic pathways to fitness in different community contexts, study various ecological processes thought to govern community assembly, and facilitate development of microbiota-directed therapeutics."