Interrelationships of Staphyliniform groups inferred from 18S and 28S rDNA sequences, with special emphasis on Hydrophiloidea (Coleoptera, Staphyliniformia)

The series Staphyliniformia is one of the mega‐diverse groups of Coleoptera, but the relationships among the main families are still poorly understood. In this paper we address the interrelationships of staphyliniform groups, with special emphasis on Hydrophiloidea and Hydraenidae, based on partial sequences of the ribosomal genes 18S rDNA and 28S rDNA. Sequence data were analysed with parsimony and Bayesian posterior probabilities, in an attempt to overcome the likely effect of some branches longer than the 95% cumulative probability of the estimated normal distribution of the path lengths of the species. The inter‐family relationships in the trees obtained with both methods were in general poorly supported, although most of the results based on the sequence data are in good agreement with morphological studies. In none of our analyses a close relationship between Hydraenidae and Hydrophiloidea was supported, contrary to the traditional view but in agreement with recent morphological investigations. Hydraenidae form a clade with Ptiliidae and Scydmaenidae in the tree obtained with Bayesian probabilities, but are placed as basal group of Staphyliniformia (with Silphidae as subordinate group) in the parsimony tree. Based on the analysed data with a limited set of outgroups Scarabaeoidea are nested within Staphyliniformia. However, this needs further support. Hydrophiloidea s.str., Sphaeridiinae, Histeroidea (Histeridae + Sphaeritidae), and all staphylinoid families included are confirmed as monophyletic, with the exception of Hydraenidae in the parsimony tree. Spercheidae are not a basal group within Hydrophiloidea, as has been previously suggested, but included in a polytomy with other Hydrophilidae in the Bayesian analyses, or its sistergroup (with the inclusion of Epimetopidae) in the parsimony tree. Helophorus is placed at the base of Hydrophiloidea in the parsimony tree. The monophyly of Hydrophiloidea s.l. (including the histeroid families) and Staphylinoidea could not be confirmed by the analysed data. Some results, such as a placement of Silphidae as subordinate group of Hydraenidae (parsimony tree), or a sistergroup relationship between Ptiliidae and Scydmaenidae, appear unlikely from a morphological point of view.     

Molecular structure of the bilin binding protein (BBP) from Pieris brassicae after refinement at 2.0 A resolution

The bilin binding protein (BBP) from the insect Pieris brassicae has been analysed for amino acid sequence, spectral properties and three-dimensional structure. The crystal structure that had been determined by isomorphous replacement has been refined at 2.0 A (1 A = 0.1 nm) resolution to an R-value of 0.20. The asymmetric unit contains four independent subunits of BBP. The co-ordinate differences are 0.25 A, in accord with the estimated error in co-ordinates. The polypeptide chain fold is characterized by an eight-stranded barrel. The connecting loops splay out at the upper end of the barrel and open it, whilst the lower end is closed. The overall shape resembles a calyx. The biliverdin IX gamma chromophore is located in a central cleft at the upper end of the barrel. The bilatriene moiety is in cyclic helical geometry with configuration Z,Z,Z and conformation syn,syn,syn. The geometry is in accord with the spectral properties and permits a correlation between sign of the circular dichroism bands and sense of the bilatriene helices. The fold of BBP is related to retinol binding protein (RBP), as had been recognized in the preliminary analysis, although the amino acid sequences of RBP and BBP show only 10% homology. There are large differences in the loops at the upper end of the barrel, whilst the segments of the centre and the lower end of the barrel superimpose closely. The ligands of BBP and RBP, biliverdin and retinol, respectively, are also similarly located.     

Enzyme-coding genes as molecular clocks: The molecular evolution of animal alpha-amylases

Summary We constructed a cDNA library for the beetle,Tribolium castaneum. This library was screened using a cloned amylase gene fromDrosophila melanogaster as a molecular probe. Beetle amylase cDNA clones were isolated from this bank, and the nucleotide sequence was obtained for a cDNA clone with a coding capacity for 228 amino acids. Both the nucleotide sequence and predicted amino acid sequence were compared to our recent results forD. melanogaster alpha-amylases, along with published sequences for other alpha-amylases. The results show that animal alpha-amylases are highly conserved over their entire length. A borader comparison, which includes plant and microbial alpha-amylase sequences, indicates that parts of the gene are conserved between prokaryotes, plants, and animals. We discuss the potential importance of this and other enzyme-coding genes for the construction of molecular phylogenies and for the study of the general question of molecular clocks in evolution.     

Correlates and predictors of the age of menarche

In a cross-sectional study of 452 girls between 10 and 16 years of age 36 indices of physical and 50 of mental development were tested for their correlation with age at menarche and chronological age, as well as for their predictive power for estimating menarche by multiple regression analysis. Indices of physical maturity and body weight when adjusted for chronological age showed the highest partial correlation coefficients with age at menarche. Among mental characters which show lower intercorrelations with menarche occurred the highest correlation coefficients for a handmotor factor "Spurennachzeichnen" and a factor "Gruppenabh?ngigkeit" (which indicates a type of social motivation). In general physical and mental factors correlate higher with chronological age than with age at menarche. By multiple regression analysis we determined 14 physical and 25 mental predictors explaining 21% and 17% respectively of the variance of age at menarche. The error of the estimate predicting menarche on body weight without knowledge of onset of menarche is +/- 1 year. Using chronological age in a sample of girls before menarche the error of the estimate only is +/- 6 months. To compare the predictive power of chronological age combined with body weight or with skeletal age the time interval is calculated within which 95% of girls attain menarche. The range of prediction extends from 4.3 to 1 year on chronological age (11-16 years); using mean body weight it can be improved by 1.8 to 6 months, while using mean skeletal age an improvement of 0.2 to 3.9 months is possible compared with body weight. The correlations between age at menarche and physical and mental variables are attributed to a common hormonal influence on rate of development.     

Biochemical characterization of chromatin fractions isolated from induced and uninduced friend erythroleukemia cells

Summary Chromatin fractions from Friend erythroleukemia cells after induction of differentiation by dimethylsulfoxide (DMSO) were compared in their biochemical characteristics to fractions from uninduced cells. Fractions were prepared by extracting chromatin from nuclei after mild micrococcal nuclease treatment with increasing concentrations of NaCl according to Sanders [1]. This procedure has been found to release chromatin containing hyperacetylated histones preferentially [2]. The fractions obtained by this procedure were analysed in respect to the amount of chromatin released, the amount of histone H1, the degree of acetylation of histone H4, the presence of non-histone proteins and the concentration of transcribed and non-transcribed sequences. It was found that the fractions differ in the amount of histone H1 present, in several non-histone proteins and in the acetylation of histonie H4, regardless whether induced or uninduced cells were analysed. The distribution of transcribed sequences versus non-transcribed sequences among the fractions was the same, demonstrating that this fractionation procedure, although leading to fractions with biochemical differences, is not able to discriminate functional states of chromatin and that the biochemical characteristics of the fractions may be common to both, active as well as inactive states of chromatin.     

The complete amino-acid sequence of the alpha and beta subunits of B-phycoerythrin from the rhodophytan alga Porphyridium cruentum

Determination of the complete amino-acid sequence of the subunits of B-phycoerythrin from Porphyridium cruentum has shown that the alpha subunit contains 164 amino-acid residues and the beta subunit contains 177 residues. When the sequences of B- and C-phycoerythrins are aligned with those of other phycobiliproteins, it is obvious that B-phycoerythrin lacks a deletion at beta-21-22 present in C-phycoerythrin. However, relative to C-phycoerythrin from Fremyella diplosiphon (Calothrix) (Sidler, W., Kumpf, B., Rüdiger, W. and Zuber, H. (1986) Biol. Chem. Hoppe-Seyler 367, 627-642), B-phycoerythrin has deletions at beta-141k-o, beta-142, beta-143, beta-147 and beta-148. The four singly-linked phycoerythrobilins at positions alpha-84, alpha-143a, beta-84 and beta-155, and the doubly-linked phycoerythrobilin at position beta-50/61 are at sites homologous to the attachment sites in C-phycoerythrin. The aspartyl residues (alpha-87, beta-87, and beta-39), that interact with the bilins at alpha-84, beta-84, and beta-155 in C-phycocyanin, are found in the homologous positions in B-phycoerythrin. B-Phycoerythrin, in common with other phycobiliproteins, contains a N gamma-methylasparagine residue at position beta-72.