Fleeting Amyloid-like Forms of Rim4 Ensure Meiotic Fidelity.

Berchowitz et al. establish that transient amyloid-like forms of Rim4, a yeast RNA-binding protein with a predicted prion domain, translationally repress cyclin CLB3 in meiosis I, thereby ensuring homologous chromosome segregation. These findings suggest that prion domains might enable formation of tightly regulated amyloid-like effectors in diverse functional settings.

Mutations in prion-like domains in hnRNPA2B1 and hnRNPA1 cause multisystem proteinopathy and ALS.

Algorithms designed to identify canonical yeast prions predict that around 250 human proteins, including several RNA-binding proteins associated with neurodegenerative disease, harbour a distinctive prion-like domain (PrLD) enriched in uncharged polar amino acids and glycine. PrLDs in RNA-binding proteins are essential for the assembly of ribonucleoprotein granules. However, the interplay between human PrLD function and disease is not understood.

Relative clonal proportions over time in mixed-genotype infections of the lizard malaria parasite Plasmodium mexicanum.

Vertebrate hosts of malaria parasites (Plasmodium) often harbour two or more genetically distinct clones of a single species, and interaction among these co-existing clones can play an important role in Plasmodium biology. However, how relative clonal proportions vary over time in a host is still poorly known. Experimental mixed-clone infections of the lizard malaria parasite, Plasmodium mexicanum, were followed in its natural host, the western fence lizard using microsatellite markers to determine the relative proportions of two to five co-existing clones over time (2-3 months).

Relative clonal density of malaria parasites in mixed-genotype infections: validation of a technique using microsatellite markers for Plasmodium falciparum and P. mexicanum.

Quantifying the relative proportion of coexisting genotypes (clones) of a malaria parasite within its vertebrate host's blood would provide insights into critical features of the biology of the parasite, including competition among clones, gametocyte sex ratio, and virulence. However, no technique has been available to extract such data for natural parasite-host systems when the number of clones cycling in the overall parasite population is likely to be large. Recent studies find that data from genetic analyzer instruments for microsatellite markers allow measuring clonal proportions.

Detecting number of clones, and their relative abundance, of a malaria parasite (Plasmodium mexicanum) infecting its vertebrate host.

Microsatellites, short tandem repeats of nucleotides in the genome, are useful markers to detect clonal diversity within Plasmodium infections. However, accuracy in determining number of clones and their relative proportions based on standard genetic analyzer instruments is poorly known. DNA extracted from lizards infected with a malaria parasite, Plasmodium mexicanum, provided template to genotype the parasite based on three microsatellite markers.