The type locality of <Emphasis Type="Italic">Pan troglodytes vellerosus</Emphasis> (Gray, 1862), and implications for the nomenclature of West African chimpanzees

We show that, in 1862, Richard Burton collected the type specimen of Pan troglodytes vellerosus not on Mount Cameroon, as has been generally assumed, but in Gabon. Therefore, P. t. vellerosus is not the correct name for the chimpanzee population of western Cameroon and southern Nigeria, if that population is taxonomically distinct. As First Reviser, we choose the name Pan troglodytes ellioti for this population of chimpanzees, based on Anthropopithecus ellioti named by Matschie [Matschie P (1914) Neue Affen aus Mittelafrika. Sitzungsber Ges Naturforsch Freunde Berlin 1914:323–342] from a specimen in the Humboldt Museum, Berlin, collected in Bascho (=Basho), Cameroon, and given to the museum in 1905.     

CytochromeBSequences Suggest Convergent Evolution of the Asian Takin and Arctic Muskox

Relationships of the takin (Budorcas taxicolor) and muskox (Ovibos moschatus) have been speculated upon for many years. Morphological and behavioral similarities between these species have led to suggestions that they are closely related. To test the hypothesis that characteristics shared by the takin and muskox stem from a recent common ancestor, we compared sequences of their mitochondrial cytochromebgenes with those of three other species of Caprinae. We present data that may support rejection of the hypothesis of recent common ancestry and suggest that similarities in behavior and morphology in these two species might be attributed to convergent evolution rather than shared phylogeny.     

Characterization of calretinin I-II as an EF-hand, Ca2+, H+-sensing domain

Calretinin, a neuronal protein with well-defined calcium-binding properties, has a poorly defined function. The pH dependent properties of calretinin (CR), the N-terminal (CR I-II), and C-terminal (CR III-VI) domains were investigated. A drop in pH within the intracellular range (from pH 7.5 to pH 6.5) leads to an increased hydrophobicity of calcium-bound CR and its domains as reported by fluorescence spectroscopy with the hydrophobic probe 2-(p-toluidino)-6-naphthalenesulfonic acid (TNS). The TNS data for the N- and C-terminal domains of CR are additive, providing further support for their independence within the full-length protein. Our work concentrated on CR I-II, which was found to have hydrophobic properties similar to calmodulin at lower pH. The elution of CR I-II from a phenyl-Sepharose column was consistent with the TNS data. The pH-dependent structural changes were further localized to residues 13-28 and 44-51 using nuclear magnetic resonance spectroscopy chemical shift analysis, and there appear to be no large changes in secondary structure. Protonation of His 12 and/or His 27 side chains, coupled with calcium chelation, appears to lead to the organization of a hydrophobic pocket in the N-terminal domain. CR may sense and respond to calcium, proton, and other signals, contributing to conflicting data on the proteins role as a calcium sensor or calcium buffer.     

Landscape genomics of Colorado potato beetle provides evidence of polygenic adaptation to insecticides

The ability of insect pests to rapidly and repeatedly adapt to insecticides has long challenged entomologists and evolutionary biologists. Since Crow's seminal paper on insecticide resistance in 1957, new data and insights continue to emerge that are relevant to the old questions about how insecticide resistance evolves: such as whether it is predominantly mono‐ or polygenic, and evolving from standing vs. de novo genetic variation. Many studies support the monogenic hypothesis, and current management recommendations assume single‐ or two‐locus models. But inferences could be improved by integrating data from a broader sample of pest populations and genomes. Here, we generate evidence relevant to these questions by applying a landscape genomics framework to the study of insecticide resistance in a major agricultural pest, Colorado potato beetle, Leptinotarsa decemlineata (Say). Genome–environment association tests using genomic variation from 16 populations spanning gradients of landscape variables associated with insecticide exposure over time revealed 42 strong candidate insecticide resistance genes, with potentially overlapping roles in multiple resistance mechanisms. Measurements of resistance to a widely used insecticide, imidacloprid, among 47 L. decemlineata populations revealed heterogeneity at a small (2 km) scale and no spatial signature of origin or spread throughout the landscape. Analysis of nucleotide diversity suggested candidate resistance loci have undergone varying degrees of selective sweeps, often maintaining similar levels of nucleotide diversity to neutral loci. This study suggests that many genes are involved in insecticide resistance in L. decemlineata and that resistance likely evolves from both de novo and standing genetic variation.     

Nitric oxide synthase: models and mechanisms

The overproduction or underproduction of nitric oxide has been implicated in pathological symptoms such as endotoxic shock, diabetes, allograft rejection, and myocardial ischimia/reperfusion injury. A thorough understanding of the biosynthesis of nitric oxide is necessary to probe and manipulate these signaling events. There is also considerable pharmacological interest in developing selective inhibitors of the several isoforms of nitric oxide synthase. The recently determined crystal structures of complexes between nitric oxide synthase and substrate, the mechanisms of the enzymatic reaction that generate nitric oxide and chemical precedents and models for these reactions are now coming into focus, but there are still numerous fascinating and unanswered questions regarding nitric oxide biosynthesis.