Integrating ecology into macroevolutionary research

On 9 March, over 150 biologists gathered in London for the Centre for Ecology and Evolution spring symposium, 'Integrating Ecology into Macroevolutionary Research'. The event brought together researchers from London-based institutions alongside others from across the UK, Europe and North America for a day of talks. The meeting highlighted methodological advances and recent analyses of exemplar datasets focusing on the exploration of the role of ecological processes in shaping macroevolutionary patterns.     

Altered accumulation of a membrane protein unique to a membrane-deoxyribonucleic acid complex in a dna initiation mutant of Bacillus subtilis.

Membrane-deoxyribonucleic acid complexes (M-bands) have been isolated from Bacillus subtilis by their affinity for crystals of Mg2+-Sarkosyl. The membrane proteins of these complexes were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Comparison of the membrane protein composition of M-band and unfractionated membrane revealed three protein components of 125,000 (mac-1), 57,000 (mac-2), and 42,000 (mac-3) daltons unique to M-band membrane. Growth of a temperature-sensitive dna initiation mutant at the restrictive temperature resulted in an accumulation in the membrane of mac-2. This accumulation did not begin, however, until cell growth had nearly ceased, some 3 to 4 h after the cessation of deoxyribonucleic acid synthesis. Upon return of the mutant to the permissive temperature, mac-2 did not begin to return to normal levels until after the first round of deoxyribonucleic acid synthesis. A protein of 30,000 daltons, common to both M-band and whole membrane, was found to disappear from the membrane when the mutant was grown at the restrictive temperature. This disappearance is the result of increased degradation or removal from the membrane followed by a decreased rate of synthesis or insertion.     

Multivariate phenotypic evolution among island and mainland populations of the ornate day gecko, Phelsuma ornata

Interpopulation variation in morphology, such as that among small island populations, plays a key role in speciation and diversification. There are two approaches to investigating evolution of morphological characters: comparing patterns of trait variances and covariances within and among populations, and testing particular adaptive scenarios. Here, we combine both approaches to infer the role of natural selection in shaping morphological variation in body size, head color pattern, and body shape among 10 populations of a day gecko, Phelsuma ornata, and its close relative, P. inexpectata, in the Mascarene Islands. We find that local populations are morphologically distinct, and that natural selection has likely influenced phenotypic diversification in the group. Lizards on small outer islands tend to be larger than lizards on the mainland of Mauritius. For body shape and head color pattern, comparisons of variation within and among populations reveal that differences among populations for some variables are too great to be explained by neutral processes alone, although we cannot identify the causal agents for this selection. These results reveal that the forces shaping different sets of organismal traits may be distinct, such that a variety of statistical approaches are needed to investigate selection in natural populations.     

The major ribonucleoprotein-associated protein kinase of vesicular stomatitis virus is a host cell protein

Ribonucleoprotein particles (RNPs) of vesicular stomatitis virus (VSV) were fractionated by column chromatography through Fractogel TSK HW-55F and by centrifugation through KCl sucrose. Analyses of fractions for protein content and for protein kinase activity indicated that the major peak of kinase activity did not correspond exactly with any of the VSV-specific proteins. Neither anti-NS nor anti-M IgG preparations inhibited protein kinase activity, and IgG did not act as an exogenous phosphate acceptor. Reconstitution of an RNP-enzyme complex did not result in a restoration of protein kinase activity. In vitro translation of VSV-specific poly(A)-containing RNA did not result in any detectable production of kinase activity. Thus, the major RNP-associated kinase is a host cell protein which is tightly bound to the RNP particle.