A resonance raman investigation of perturbed states of tree and fungal laccase

Resonance Raman (RR) spectra of Rhus vernicifera laccase and Polyporus versicolor laccase in several perturbed states are reported. Coordination of fluoride to the type 2 copper of either laccase does not produce RR-detectable changes at the type 1 sites. Removal of the type 2 copper of Rhus laccase induces RR-detectable changes at the type 1 site that are most readily interpreted as arising from a heterogeneous sample. Freezing the Rhus laccase does not induce changes in its RR spectrum; further cooling to liquid nitrogen temperature induces a change in the type 1 site that is reflected in the RR spectrum. Electron paramagnetic resonance spectra confirm that the structure of the type 1 site is temperature dependent. Some variability in the Rhus laccase RR spectrum is observed in the absence of exogenous ligands or other perturbations; it is suggested that Rhus laccase preparations may be heterogeneous with respect to the structure of the type 1 copper site.     

SplitsTree: analyzing and visualizing evolutionary data

MOTIVATION: Real evolutionary data often contain a number of different and sometimes conflicting phylogenetic signals, and thus do not always clearly support a unique tree. To address this problem, Bandelt and Dress (Adv. Math., 92, 47-05, 1992) developed the method of split decomposition. For ideal data, this method gives rise to a tree, whereas less ideal data are represented by a tree-like network that may indicate evidence for different and conflicting phylogenies. RESULTS: SplitsTree is an interactive program, for analyzing and visualizing evolutionary data, that implements this approach. It also supports a number of distances transformations, the computation of parsimony splits, spectral analysis and bootstrapping.      

Adaptive accuracy of temperature oviposition preferences in newts

Oviposition-site choice has profound fitness consequences for both a mother and her offspring. The adaptive significance of oviposition behaviour for both generations depends on two rarely considered assumptions: (1) the fit of maternal oviposition preferences with local phenotypic optimum (adaptive accuracy) and (2) the predictability of future conditions for developing offspring based on conditions at the time of oviposition. We examined both assumptions using temperature oviposition preferences (T _p,o) previously measured under laboratory conditions in the alpine newt, Ichthyosaura (formerly Triturus) alpestris. Analyses of temperature time series in the newt natural environment revealed, in agreement with oviposition-site choice of female newts, that T _p,o were closer to phenotypic optima at the water surface than at the maximal depth (bottom). Temperature time series in both depths contained a high proportion of predictable variation, though bottom thermal conditions were more predictable than those at the water surface. We concluded that female newts have to trade the adaptive accuracy of T _p,o for the predictability of future thermal conditions at the time of oviposition.