The new higher level classification of eukaryotes with emphasis on the taxonomy of protists

This revision of the classification of unicellular eukaryotes updates that of Levine et al. (1980) for the protozoa and expands it to include other protists. Whereas the previous revision was primarily to incorporate the results of ultrastructural studies, this revision incorporates results from both ultrastructural research since 1980 and molecular phylogenetic studies. We propose a scheme that is based on nameless ranked systematics. The vocabulary of the taxonomy is updated, particularly to clarify the naming of groups that have been repositioned. We recognize six clusters of eukaryotes that may represent the basic groupings similar to traditional "kingdoms." The multicellular lineages emerged from within monophyletic protist lineages: animals and fungi from Opisthokonta, plants from Archaeplastida, and brown algae from Stramenopiles.     

Glandularia X hybrida (Verbenaceae), a new combination for a common horticultural plant

A new combination,Glandularia x hybrida, and a lectotype are proposed for the common Garden Vervain (Verbena xhybrida). The plant is of horticultural origin, but occurs widely in North America and Mexico as an adventive.     

Robust score statistics for QTL linkage analysis

The traditional variance components approach for quantitative trait locus (QTL) linkage analysis is sensitive to violations of normality and fails for selected sampling schemes. Recently, a number of new methods have been developed for QTL mapping in humans. Most of the new methods are based on score statistics or regression-based statistics and are expected to be relatively robust to non-normality of the trait distribution and also to selected sampling, at least in terms of type I error. Whereas the theoretical development of these statistics is more or less complete, some practical issues concerning their implementation still need to be addressed. Here we study some of these issues such as the choice of denominator variance estimates, weighting of pedigrees, effect of parameter misspecification, effect of non-normality of the trait distribution, and effect of incorporating dominance. We present a comprehensive discussion of the theoretical properties of various denominator variance estimates and of the weighting issue and then perform simulation studies for nuclear families to compare the methods in terms of power and robustness. Based on our analytical and simulation results, we provide general guidelines regarding the choice of appropriate QTL mapping statistics in practical situations.     

Phylogenetic systematics of Colotis and associated genera (Lepidoptera: Pieridae): evolutionary and taxonomic implications

We investigated the genetic diversity and phylogenetic placement of the butterflies in the genus Colotis and eight related pierid genera using sequence information from two mitochondrial and two nuclear genes. To establish the status of species, we initially barcoded 632 specimens representative of all genera and most species and subspecies in those genera. A subset was then selected for phylogenetic analysis where additional gene regions were sequenced: 16S rRNA (523 bp), EF‐1α (1126 bp) and wg (404 bp). DNA barcode results were largely congruent with the traditional classification of species in the Colotis group, but deep splits or lack of genetic divergence in some cases supported either species‐level differentiation or synonymy. Despite using information from four genes, the deeper nodes in our phylogeny were not strongly supported, and monophyly of the ‘Colotis group’ and the genera Colotis and Eronia could not be established. To preserve the monophyly of Colotis, we revive the genus Teracolus for three outlying species previously in Colotis (i.e. Colotis eris, Colotis subfasciatus and Colotis agoye), as well as the genus Afrodryas for Eronia leda. The position of Calopieris is unresolved although it appears to be well outside the molecular variation in Colotis (s.l.). A dispersal/vicariance analysis suggested that major diversification in Colotis (s.str.) occurred in Africa with subsequent dispersal to India and Madagascar.     

Validation of measurements of ventilation-to-perfusion ratio inequality in the lung from expired gas.

The analysis of the gas in a single expirate has long been used to estimate the degree of ventilation-perfusion (Va/Q) inequality in the lung. To further validate this estimate, we examined three measures of Va/Q inhomogeneity calculated from a single full exhalation in nine anesthetized mongrel dogs under control conditions and after exposure to aerosolized methacholine. These measurements were then compared with arterial blood gases and with measurements of Va/Q inhomogeneity obtained using the multiple inert gas elimination technique. The slope of the instantaneous respiratory exchange ratio (R slope) vs. expired volume was poorly correlated with independent measures, probably because of the curvilinear nature of the relationship due to continuing gas exchange. When R was converted to the intrabreath Va/Q (iV/Q), the best index was the slope of iV/Q vs. volume over phase III (iV/Q slope). This was strongly correlated with independent measures, especially those relating to inhomogeneity of perfusion. The correlations for iV/Q slope and R slope considerably improved when only the first half of phase III was considered. We conclude that a useful noninvasive measurement of Va/Q inhomogeneity can be derived from the intrabreath respiratory exchange ratio.     

Biotransformation of l-DOPA to Dopamine in the Substantia Nigra of Freely Moving Rats: Effect of Dopamine Receptor Agonists and Antagonists

Abstract: We investigated the effects of continuous intranigral perfusion of dopamine D1 and D2 receptor agonists and antagonists on the biotransformation of locally applied l -DOPA to dopamine in the substantia nigra of freely moving rats by means of in vivo microdialysis. The "dual-probe" mode was used to monitor simultaneously changes in extracellular dopamine levels in the substantia nigra and the ipsilateral striatum. Intranigral perfusion of 10 µ M l -DOPA for 20 min induced a significant 180-fold increase in extracellular nigral dopamine level. No effect of the intranigral l -DOPA administration was observed on dopamine levels in the ipsilateral striatum, suggesting a tight control of extracellular dopamine in the striatum after enhanced nigral dopamine levels. Continuous nigral infusion with the D1 receptor agonist CY 208243 (10 µ M ) and with the D2 receptor agonist quinpirole at 10 µ M (a nonselective concentration) attenuated the l -DOPA-induced increase in dopamine in the substantia nigra by 85 and 75%, respectively. However, perfusion of the substantia nigra with a lower concentration of quinpirole (1 µ M ) and the D1 antagonist SCH 23390 (10 µ M ) did not affect the nigral l -DOPA biotransformation. The D2 antagonist (−)-sulpiride (10 µ M ) also attenuated the l -DOPA-induced dopamine release in the substantia nigra to ∼10% of that of the control experiments. We confirm that there is an important biotransformation of l -DOPA to dopamine in the substantia nigra. The high concentrations of dopamine formed after l -DOPA administration may be the cause of dyskinesias or further oxidative stress in Parkinson's disease. Simultaneous administration of D1 receptor agonists with l -DOPA attenuates the biotransformation of l -DOPA to dopamine in the substantia nigra. The observed effects could occur via changes in nigral GABA release that in turn influence the firing rate of the nigral dopaminergic neurons.