A Reversible Color Polyphenism in American Peppered Moth (Biston betularia cognataria) Caterpillars

Insect body color polyphenisms enhance survival by producing crypsis in diverse backgrounds. While color polyphenisms are often indirectly induced by temperature, rearing density, or diet, insects can benefit from immediate crypsis if they evolve polyphenisms directly induced by exposure to the background color, hence immediately deriving protection from predation. Here, we examine such a directly induced color polyphenism in caterpillars of the geometrid peppered moth (Biston betularia). This larval color polyphenism is unrelated to the genetic polymorphism for melanic phenotypes in adult moths. B. betularia caterpillars are generalist feeders and develop body colors that closely match the brown or green twigs of their host plant. We expand on previous studies examining the proximal cues that stimulate color development. Under controlled rearing conditions, we manipulated diets and background reflectance, using both natural and artificial twigs, and show that visual experience has a much stronger effect than does diet in promoting precise color matching. Their induced body color was not a simple response to reflectance or light intensity but instead specifically matched the wavelength of light to which they were exposed. We also show that the potential to change color is retained until the final (sixth) larval instar. Given their broad host range, this directly induced color polyphenism likely provides the caterpillars with strong protection from bird predation

A communal catalogue reveals Earth's multiscale microbial diversity

Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

A communal catalogue reveals Earth’s multiscale microbial diversity

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

A mutation affecting polycystin-1 mediated heterotrimeric G-protein signaling causes PKD

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the growth of renal cysts that ultimately destroy kidney function. Mutations in the PKD1 and PKD2 genes cause ADPKD. Their protein products, polycystin-1 (PC1) and polycystin-2 (PC2) have been proposed to form a calcium-permeable receptor-channel complex; however the mechanisms by which they function are almost completely unknown. Most mutations in PKD1 are truncating loss-of-function mutations or affect protein biogenesis, trafficking or stability and reveal very little about the intrinsic biochemical properties or cellular functions of PC1. An ADPKD patient mutation (L4132Δ or ΔL), resulting in a single amino acid deletion in a putative G-protein binding region of the PC1 C-terminal cytosolic tail, was found to significantly decrease PC1-stimulated, G-protein-dependent signaling in transient transfection assays. Pkd1ΔL/ΔL mice were embryo-lethal suggesting that ΔL is a functionally null mutation. Kidney-specific Pkd1ΔL/cond mice were born but developed severe, postnatal cystic disease. PC1ΔL protein expression levels and maturation were comparable to those of wild type PC1, and PC1ΔL protein showed cell surface localization. Expression of PC1ΔL and PC2 complexes in transfected CHO cells failed to support PC2 channel activity, suggesting that the role of PC1 is to activate G-protein signaling to regulate the PC1/PC2 calcium channel